IEC/TR 62685 Test requirements and EMC

IEC/TR 62685:2010 is NOT harmonized. The full title is Industrial communication networks – Profiles – Assessment guideline for safety devices using IEC 61784-3 functional safety communication profiles  (FSCPs).

IEC/TR 62685 was produced from the test requirements of the German BGIA document GS-ET-26 and covers the requirements of safety components within a safety function. It covers the issue of labeling and  EMC as well as mechanical and climatic tests. This closes some of the gaps left by EN ISO 13849-1 and EN 61784-3. Overall the document is more relevant to safety component manufacturers than plant and  machine builders. However, as the document contains a good comparison of EMC requirements, it may also  be of interest to machine builders.

Engineering Safety Standards

There is no intention at this point to provide a complete list of the European engineering safety standards. Over 600 standards are listed as harmonized under the Machinery Directive alone. The following section  addresses a selection of the general safety standards. They are explained in various degrees of detail,  depending on the significance of the individual standard.

Machinery Directive

98 /37/EC and its successor 2006/42/EC have special significance in terms of the functional safety of machinery. This directive, generally known as the “Machinery Directive”, is concerned with the standardization of European safety requirements on machinery.

Content:
The Machinery Directive covers the key aspects of machine safety. The contents of the Machinery Directive are as follows:

• Scope, placing on the market, freedom of movement
• Conformity assessment procedures
• CE marking
• Essential health and safety requirements
• Categories of machinery and the applicable conformity assessment procedures
• EC declaration of conformity and type-examination
• Requirements of notifi ed bodies

Validity:
The Machinery Directive 2006/42/EC replaced the previous version 98/37/EC with effect from 29.12.2009. There is no transition period.

Standards relating to the Machinery Directive:
At this point, it makes no sense to name all the standards that are listed under the Machinery Directive and are therefore considered as harmonized. As of Spring 2011, there were more than 700 standards listed directly. To then add all the standards that are relevant indirectly via the standards that are listed directly, would go far beyond the scope of this compendium. The following chapters will therefore concentrate on those standards for the Machinery Directive which are of general significance.

Standards, Directives and Laws: Directives

Of the almost 30 active directives now available, only a small selection is relevant to the typical machine builder. Some directives may have a very long or bureaucratic title in addition to the directive number (e.g. 2006/42/EC). Variations can be seen in the last part of the directive number. This will contain EC, EU, EG, EWG or some other abbreviation, depending on the language area and issue date. As a result it is generally very difficult to name the directive. These long titles are often abbreviated separately, even though this can  also lead to misunderstandings. Here is a list of some of the key directives with both their official title and  their usual, though unofficial, abbreviated title:

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The aim of the directives is to guarantee freedom of movement within the EU. The full texts of the directives http://eur-lex.europa.eu/de/legis/index.htm are available from the EU. Of all these directives, only the  Machinery Directive will be examined here in any further detail. However, the list of relevant standards will naturally refer to standards that relate to other directives.

Seven Steps to a CE Mark: Step 7, Affix the CE Marking

The CE mark may be affixed once the EC declaration of conformity has been issued.

It’s important that CE marking for the complete machine is clearly  distinguishable from any other CE markings, e.g. on components. To  avoid confusion with any other  markings, it is advisable to affix the CE marking for the complete machine to the machine type plate, which should also contain the name and address of the manufacturer.

Seven Steps to a CE Mark: Part Six, Issue the Declaration of Conformity

By issuing the EC declaration of conformity, the manufacturer declares that they have considered all the  directives that apply to the product. The person signing an EC declaration of conformity must be authorized to represent his company. This means that the signatory is legally entitled to execute a legal transaction, such as signing the EC declaration of conformity, on account of their job function.

When an authorized employee of the company adds their valid signature to an EC declaration of conformity, they trigger the liability of the natural responsible person and, if applicable, the company as a legal entity.

The declaration may also be signed by an authorized representative, who is established in the EU.

The new Machinery Directive requires the declaration to name the person authorized to compile the technical documentation. This person must be established in the EU.

The Seven Steps to a CE Mark: Step 5, Compile the Technical Documentation

In accordance with the Machinery Directive, technical documentation specifically comprises:

• An overall drawing of the machinery and drawings of the control circuits
• Full, detailed drawings (accompanied by any calculation notes, test results, etc.) required to check the conformity of the machinery with the essential health and safety requirements
• A list of the essential requirements of this directive, standards and other technical specifications used in the design of the machinery, a description of the protective measures implemented to eliminate hazards presented by the machinery (generally covered by the risk analysis)
• Technical reports or certificates; reports or test results showing conformity
• The machine’s operating instructions
• A general machine description
• Declaration of conformity or declaration of incorporation plus the assembly instructions
• Declarations of conformity for the machines or devices incorporated into the machinery

This documentation does not have to be permanently available in material form. However, it must be possible to assemble it and make it available within a period of time commensurate with its importance. It must be retained for at least ten years following the date of manufacture and be available to present to the relevant national authorities. In the case of series manufacture, that period shall start on the date that the last machine is produced.

The Seven Steps to a CE Mark: Step 4, Performing the Risk Assessment

The manufacturer is obliged to carry out a risk analysis to determine all the hazards associated with his machine. The result of this analysis must then be considered in the design and construction of that machine. The contents and scope of a hazard analysis are not specified in any directive, but EN ISO 12100 describes the general procedure.

All relevant hazards must be identified, based on the intended use – taking into consideration all the lifecycles once the machine is first made available on the market. All the various groups who come into contact with the machine, such as operating, cleaning or maintenance staff for example, are also considered.

The risk is assessed and evaluated for each hazard. Risk-reducing measures are established in accordance with the state of the art and in compliance with the standards. The residual risk is assessed at the same time: If it is too high, additional measures are required. This iterative process is continued until the necessary safety is achieved.

Seven Steps to a CE Mark: Step Three, Ensure That Safety Regulations Are Met

It is the responsibility of the machine manufacturer to comply with the essential health and safety requirements in accordance with Annex I of the Machinery Directive. The formulation of these requirements is relatively abstract, but specifics are provided through the EU standards.

The EU publishes lists of directives and the related harmonized standards. Application of these standards is voluntary, but compliance does provide presumption of conformity with the regulations. This can substantially reduce the amount of evidence required, and a lot less work is needed to incorporate the risk assessment.

Seven Steps to a CE Mark: Step Two, Check the Appplication of Additional Directives

Where machinery is also subject to other EU directives, which cover different aspects but also provide for the affixing of the CE mark, the provisions of these directives must be met before the CE mark is applied. If the machine contains electrical equipment, for example, it will often be subject to the Low Voltage Directive and, possibly, the EMC Directive too.

Seven Steps to a CE Mark: Step 1, Categorize the Product

Step 1: Categorize the product
The CE marking process starts by categorizing the product.

The following questions need to be answered:
• Is the product subject to the Machinery Directive?

Here it’s important to note that with the new Machinery Directive coming into force, some new products have been introduced (e.g. pressure vessels, steam boilers and funicular railways), while others have been omitted (e.g. electrical household and office equipment).

• Is the product listed in Annex IV of the Machinery Directive?

Annex IV of the Machinery Directive lists machinery that is  considered “particularly hazardous”, such as presses,  woodworking machinery, service lifts, etc. In this case, CE marking and the declaration of conformity must meet special requirements.

• Is the machine a subsystem or partly completed machinery?

Manufacturers issue an EC declaration of conformity for functional machines that meet the full scope of Annex I of the Machinery Directive. For subsystems, e.g. robots, which cannot yet meet the full scope of
Annex I, the manufacturer issues a manufacturer’s declaration in accordance with Annex II B.

The new Machinery Directive refers to subsystems as “partly completed machinery”. From the moment the new Machinery Directive becomes valid, all partly completed machinery must be accompanied by a declaration of incorporation in accordance with Annex II. At the same time, the manufacturer must perform a risk assessment and provide assembly instructions in accordance with Annex VI. Effectively the  manufacturer’s declaration or declaration of incorporation bans the subsystem from being put into service, as the machine is incomplete and as such may not be used on its own.

• Is it a safety component?

Under the old Machinery Directive, safety components are treated separately and are not awarded a CE mark, although it is necessary to produce a declaration of conformity. Under the new Directive they will be treated as machinery and will therefore be given a CE mark.

Potential assessment procedures in accordance with the new Machinery Directive.

Machinery for own use

CE certification for individual machines and the overall plant.

The Machinery Directive also obliges users who manufacture machinery for their own use to comply with the Directive. Although there are no problems in terms of free trade - after all, the machine is not to be traded - the Machinery Directive is applied to guarantee that the safety level of the new machine matches that of other machines available on the market.

Importing a machine from a country outside the EU

When a machine is imported from a third country for use within the EU, that machine must comply with the Machinery Directive when it is made available on the EU market.Anyone who places a machine on the market for the first time within the European Economic Area must have the necessary documentation to establish conformity, or have access to such documentation. This applies whether you are dealing with an  “old machine” or new machinery.

CE Marking of Plant and Machinery

According to the Machinery Directive, a machine manufacturer is anyone who assembles machines or  machine parts of various origins and places them on the market.

A manufacturer may be the actual machine builder or – where a machine is modified – the operator. In the case of assembled machinery, it may be the manufacturer, an assembler, the project manager, an engineering company or the operator himself, who assembles a new installation from various machines, so that the different machine parts constitute a new machine.

However, according to the Machinery Directive, only one manufacturer is responsible for the design and manufacture of the machine. This manufacturer or his authorized representative takes responsibility for implementing the administrative procedures for the entire plant. The manufacturer may appoint an authorized representative, who must be established in the EU, to assume responsibility for the necessary procedures for placing the product on the market:

• Compiling the plant’s technical documentation
• Complying with the technical annex
• Providing operating instructions for the plant
• Affixing the CE mark in a suitable position on the plant and drawing up a declaration of conformity for the  entire plant

It’s important that the manufacturer considers the safety aspect early, as the contracts are being formulated or in the components’ requirement manual. The documentation shall not be compiled solely from the point of view of machine performance. The manufacturer is responsible for the whole of the technical documentation and must determine the part that each of his suppliers is to undertake in this process.

Use of machinery in the European Economic Area
Irrespective of the place and date of manufacture, all machinery used in the European Economic Area for the fi rst time from 01.01.1995 is subject to the EU Machinery Directive and as such must be CE certified.

Assembled machinery
On large production lines a machine may often consist of several individual machines assembled together. Even if each of these bears its own CE mark, the overall plant must still undergo a CE certification process.

CE Marking of Machinery: What is a machine?

For the purposes of the Directive, one definition of a machine is:

An assembly of linked parts or components, at least one of which moves, and which are joined together for a specific application. (see Article 2 of the Machinery Directive)

Example of a machine for the purposes of the Directive.

 

The following are also considered as machines for the purposes of the Machinery Directive:

• An assembly of machines or complex plants (complex plants include production lines and special purpose machinery made up of several machines)
• Safety components (The issue of which components to classify as safety components is very controversial. As yet there is no discernible, uniform trend.)
• Interchangeable equipment that can modify the basic functions of a machine.

There is also a list of exceptions where machinery falls under the scope of the Directive by definition, but for which other statutory provisions generally apply.

Legal Principles of the CE Mark and the Machinery Directive

The obligation to affix CE marking extends to all products which fall under the scope of directives providing for such marking and which are destined for the single market. CE marking should therefore be affixed to the following products that fall under the scope of a directive:

• All new products, irrespective of whether they were manufactured in member states or third-party  countries
• Used products imported from third-party countries and second hand products
• Products that have been substantially modified and fall under the scope of the directives as new products.

The directives may exclude certain products from CE marking.

The manufacturer uses the declaration of conformity to confirm that his product meets the requirements of the relevant directive(s).

The information that follows is intended to explain CE marking in terms of the Machinery Directive.

The Basis of Machine Safety: Machinery Directive and CE mark

When the Machinery Directive (MD) was ratified in 1993, the aim was to remove trade barriers and enable a free internal market within Europe. After a two-year transition period, the Machinery Directive has been binding in Europe since 01.01.1995. It describes standardized health and safety requirements for interaction between man and machine and replaces the host of individual state regulations that existed on machinery safety. The new Machinery Directive 2006/42/EC has applied since 29.12.2009.

The CE mark stands for “Communauté Européenne”. A manufacturer uses this mark to document the fact that he has considered all the European internal market directives that are relevant to his product and applied all the appropriate conformity assessment procedures. Products that carry the CE mark may be imported and sold without considering national regulations. That’s why the CE mark is also referred to as the “Passport to Europe”.

Generally speaking, all directives in accordance with the new concept (“new approach”) provide for CE marking. Where a product falls under the scope of several directives which provide for CE marking, the marking indicates that the product is assumed to conform with the provisions of all these directives.

Standards, directives and laws in the European Union (EU)

Relationship between harmonized standards and laws in the EU.

 The European Union is increasingly merging. Machine builders will recognize this in the increasing  harmonization of laws, regulations and provisions. Not that long ago, each country published its own guidelines on the different areas of daily life and the economy, but today you’ll find more and more standardized regulations within Europe.

How are European laws, directives and standards connected?

Initially, the EU formulates general safety objectives via directives. These safety objectives need to be specified more precisely; the actual provision is made via standards.

EU directives generally deal with specific issues. The directives themselves have no direct impact on individual citizens or companies. They only come into effect through the agreements of individual countries within the EU, who incorporate these directives into their domestic law. In each EU country, a law or provision refers to the relevant EU directive and thus elevates it to the status of domestic law. Between the time a directive is adopted and the point at which it is incorporated into domestic law there is inevitably a transition period, during which time the directive awaits incorporation into domestic law in the individual  countries. However, for users this is generally unimportant because the directives themselves provide clear indication on the respective validity date. So although the titles of these documents describe them almost harmlessly as directives, in practice they have legal status within the EU.

This explains how laws and directives are connected, but doesn’t deal with the issue of the standards.

Although the standards themselves make interesting reading, on their own they have no direct legal relevance until they are published in the Official Journal of the EU or are referenced in domestic laws and provisions. These are the publications by which a standard can acquire “presumption of conformity”. Presumption of conformity means that a manufacturer can assume he has met the requirements of the corresponding directive provided he has complied with the specifications in the standard. So presumption of conformity confirms proper conduct, as it were. In a formal, legal context this is called a reversal of the burden of proof. Where the manufacturer applies a harmonized standard, if there is any doubt, misconduct will need to be proven. Where the manufacturer has not applied a harmonized standard, he will need to prove that he has acted in compliance with the directives.

If a manufacturer does not comply with a standard, it does not necessarily mean that he has acted incorrectly. Particularly in innovative industries, relevant standards either may not exist or may be inadequate. The manufacturer must then demonstrate independently that he has taken the necessary care to comply with the safety objectives of the relevant directives. Such a route is usually more complex but, in an innovative industry, it is often unavoidable.

It’s important to stress that the EU does not publish every standard in the Official Journal, so many are still not harmonized. Even if such a standard is deemed to have considerable technical relevance, it will still not have presumption of conformity. However, sometimes a standard that has not been listed in the EU Official Journal does achieve a status that’s comparable with harmonization. This is the case, for example, when a harmonized standard makes reference to the respective standard. The standard that is not listed in the EU Official Journal is then harmonized “through the back door”, as it were.

Product Liability and Protective Laws

In addition to the broad text of the general clausein § 823 para. 1 of the German Civil Code (BGB), liability  to pay compensation may also arise in accordance with § 823 para. 2:

§ 823 para. 2 of the German Civil Code (BGB) “The same liability (meaning liability to pay compensation) is held by anyone who breaks a law that is intended to protect another person.”

In this case, the activity that violates the protected right violates a “protective law”: Protective law means that the respective legal provision is (also) intended to protect the individual through some other body of legislation and therefore, in the event of damage, violation of the law itself already establishes liability for compensation.

In terms of the liability risks from violating a protective law, special laws that determine safety requirements for certain product groups have a role to play. The most important of these is the law covering technical work equipment and consumer products (Equipment and Product Safety Act/GPSG), as it covers a wide range of products: Hair dryers, kettles and skid loaders fall under its scope just as much as respiratory equipment and complex machinery. As various EC CE marking directives have also been “reflected” nationally via the GPSG and its subordinate ordinances (incl. the low voltage, ATEX, machinery, toys, pressure equipment, recreational craft, lifts, gas appliances directives), failure to comply with the safety specifications contained in the CE regulations can lead to unexpected liability risks. Further CE directives
have been implemented via separate legislation, which can also be combined with § 823 para. 2 of the German Civil Code (BGB) in the event of damage (e.g. EMC Act/EMVG, Medical Product Act/ MPG, Radio and Telecommunications Terminal Equipment Act/FTEG).

So, if an unsafe product is put into circulation, liability may arise due to violation of this type of technical safety regulation – in addition to liability under the Product Liability Act and § 823 para. 1 of the German Civil Code (BGB).

 

Hazard prevention measure, warning, retrofit, recall

If after-sales product monitoring establishes that a product which has been put into circulation fails to meet safety expectations, the producer should check whether a hazard prevention measure is indicated with regard to the respective product, in order to avoid liability risks. In the context of this Safety Compendium, this includes any measures to prevent, remove or reduce hazards emanating from products that have already been put into circulation (e.g. warnings, new operating instructions, safety uploads, on-site retrofits or factory recalls).

Prerequisites for hazard prevention measure
There is no general answer to the question as to when such a hazard prevention measure must be implemented. It depends on the circumstances of the individual case, taking into consideration the extent of the threatened damage and the likelihood of its occurrence. Expressed in economic terminology, the “expected loss value” is decisive, i.e. the product resulting from the extent of loss and the probability of occurrence. The producer must therefore analyze:

1. How high is the probability of the damage occurring:
Are individual batches affected or does the defect apply to the whole series? Does the damage occur when the product is applied in accordance with its intended use or only in cases of foreseeable misuse? Does it need an accumulation of multiple random behavior modes? Does the damage only occur after an extended period of use? Do the operating instructions contain a warning against this behavior?

2. What is the threatened damage: 
 Assuming that the product defect results in damage, what is to be expected? Simply material damage or minor, even serious personal injury?

Purely economic reasons (i.e. high recall costs or loss of image) are not an argument for rejecting the implementation of a hazard prevention measure, particularly when significant protected rights are at stake.

Provided the damage occurred in conjunction with the use of the product, it is irrelevant whether it’s already been possible to establish the actual cause of the damage in detail. So it is not acceptable to wait until an established engineering process has been followed concerning the cause of the damage. However, the producer will of course have the opportunity to check whether a product defect is actually present before introducing any measures. So there is no need for any knee-jerk reactions.

If the producer receives notification of damage, during product monitoring for example, he can first of all initiate some checks to verify whether the reported damage (e.g. a fragile glass part) can actually be attributed to a product defect or is purely down to transport damage or damage resulting from improper use. If it is established that a product defect is responsible for the damage, the producer must launch countermeasures, even if it has not yet been established whether the defect occurred during the temperature setting, for example, or in some other area of the glass blowing process.

Internal company risk prevention
It makes sense to set up an internal recall management procedure which, in case of an emergency, will enable a fast, efficient reaction to any product hazards that arise. Taking out recall insurance is another factor to consider.

Product Liability: Liability of the supplier

Liability of the Supplier

The supplier is the producer of a subproduct. He must therefore be responsible for any hazards emanating from his subproduct.

The design obligations for the supplied parts depend to a certain extent on the purchaser’s safety expectations. If the supplier knows the intended use of the end product, he must manufacture an appropriate part. He must also consider any known or conceivable misuse of the end product by the end user. In particular he must comply with the prescribed specifications and quality assurance requirements of his client.

The supplier is also obliged to warn his client of any hazards associated with the supplied product, which will not be generally known in the end producer’s own industry. The supplier must provide plain answers to his client’s inquiries about specific hazards. However, the supplier may plead ignorance to questions regarding product suitability, provided there is no further duty of disclosure.

 The Federal Court of Justice (FCJ) decided as follows: A producer purchased 25 kg hobbocks, i.e. metal buckets with two movable carry handles, from a supplier. A painter had an accident while carrying one of these hobbocks, which he had filled with a 50 kg plastic mass. The end producer had previously asked the supplier whether the bucket could carry a 50 kg load. The supplier replied that the bucket was suitable for 25 kg and if he wished to fill it with 50 kg, that was his decision. The FCJ decided that the supplier was entitled to give this reply, from which it was clear that the suitability of the product was only assured up to a 25 kg load.

Liability in the event of joint production

The legal concept of the one-stop producer who manufactures every part of his product himself before assembling it has long felt like a historical description and is barely seen now in practice, with ever lower vertical integration. This division of labor in production creates new questions, particularly with regard to how areas of responsibility are divided between supplier and end producer.

Liability of the producer of the end product

Liability of the producer of the end product
The end producer or assembler, who puts the individual product components together, has overall liability for the end product being free from defects.

In the area of design, the end producer must ensure that the product part purchased from the supplier fulfills the function for which the end product is intended to be used, in accordance with the material specifications and load capacity parameters. So one of the most important tasks of the end producer is to specify the supplied product correctly and in detail. He must describe this precisely (e.g. material type, material properties, degree of hardness, dimensions, tolerance ranges, weight, manufacturing specifications, load capacity, reject ppm values, test methodologies etc.). Through precise target specifications he must also ensure that the supplied product does not show any safety-related defects (e.g. description of all operating conditions, application areas, operating hours, information regarding peak load, potential for excess mechanical stress, potential for misuse).

In terms of manufacturing, it is the responsibility of the end producer to ensure that the correct material is selected and used in the production of the supplied products. If the end producer does not come to an agreement with the supplier about the way in which the product is to be manufactured, whether through instruction or contractual agreement, he must undertake a type test of the supplied product in accordance with the latest state of scientific and technical knowledge.
 
Example: The material, diameter and thread of screws should be tested for load capacity; bottles of mineral water for pressure resistance; carry handles and mounting brackets for tear strength.

These testing obligations can be delegated in part to the supplier; in practice this is often achieved through quality assurance agreements. These will relate to the design and manufacture of the product and will specify certain quality assurance measures and test techniques. In practice, the details are legally very demanding.

For the necessary specifications and inspections or tests, reference is often made to a technical standard. Additional quality assurance measures such as a feasibility study result in the supplier’s implementation program.

Case law has decided that the end producer can rely on the fact that the supplier builds the components to the contractually agreed quality requirements and inspects the quality himself. By selecting a renowned supply company who will carry out a thorough inspection, secure the necessary certification for the component and conclude quality assurance agreements, the end producer can reduce the level of his own inspection work.
 
An end producer must also warn against any hazards resulting from the danger associated with the supplied product. What’s more, the end producer is obliged to forward the usage instructions or warnings provided by the supplier to the user of the product, and to incorporate these into the overall operating manual that he will produce.

Product Monitoring Duty

Liability in tort recognizes another defect group, known as product monitoring defects. This duty does not concern the producer until the product he has developed and manufactured is put into circulation. This term was developed from case law and describes the producer’s obligation to monitor the product in terms of its safety-related behavior on the market, even after it has been successfully put into circulation.

The producer must track the application of his product in practice, i.e. by evaluating specialist findings in  industry journals, in the media or at specialist events and exhibitions. The product monitoring duty also includes monitoring product development at key competitors.
A well structured, internal organization is therefore required, to ensure that:
• monitoring of the market is guaranteed
• the relevant information is evaluated and
• the report reaches the decision maker.

A sophisticated product monitoring program can be achieved as part of a company’s quality assurance management.

As a second step, decision makers must draw conclusions from any notifications of damage. The following questions need to be answered:
• Does the existing design need to be changed for future product series?
• Should additional hazard warnings be incorporated for existing and future customers?
• Does a previously undetected product hazard indicate the need for an avoidance measure (e.g. a public warning, a retrofit action or a recall)?

For example, once a product has been put into circulation, should increased notifications of damage and new academic reports in the technical press reveal that a certain safety bolt ceases to be effective at high temperatures, the producer will indicate on any unsold products that additional protection is required during the summer months. At the same time he will inform his customers about the risk. If the customers are known to him by name, this will be easy to carry out, but this is unfortunately quite rare in practice. Where the names of customers are unknown, a retrospective warning via the main points of sale, technical journals or other public media will need to be considered.

However, the producer does not have to consider instances of misuse in terms of product monitoring. If the product is used for purposes other than those intended or is converted without authorization, there is no obligation to act in terms of product monitoring.

Example: An industrial operator buys a complex technical machine and converts it without  authorization or agreement from the producer; the original producer is not required to advise the operator of any safety deficiencies relating to the conversion. 

Product Liability: Principles of the duty to warn

Lawyers also understand that certain risks are technically and structurally unavoidable. The user must be able to protect himself by behaving correctly, but at the same time he must be aware of the residual risk. For this reason, case law has given producers a duty to warn: The duty in this case is to further minimize the residual risk with the aid of operating instructions, warnings, symbols, training specifications etc. The principle here is that, wherever possible, a product should be designed to be safe and free from defects. The producer cannot therefore be content to overlook these options and simply refer to the hazards. The duty to warn refers to the residual risks that remain on a product even when every possibility has been exploited in its design and  manufacture.

Definition of the producer’s duty to inform should always be based on the least informed group. The greater the  extent of the potential consequential loss and the more concealed the danger, the more explicit the warnings must be. If the product harbors a health risk, warnings must be so explicit that the user deems the danger  plausible. In such cases, general guidelines regarding correct behavior are not enough; the threatened  consequences and health risks in the event of non-compliance must be described.

Indicating that the safety gap must be set correctly before using the machine and that this setting must be checked, is not enough. Appropriate warnings must make it clear that there is the threat of a serious hand injury if the safety gap is not set correctly.

There is no duty to inform where such information is evident to the general public or to specific user groups.

For example, it is evident and recognizable that a knife can cut.

The duty to warn also extends to obvious misuse of the product. However, the producer does not have to account for unreasonable, unforeseeable and improper use of his product.

Operating instructions should not only show the correct way to install or assemble the product, but must also provide separate warnings against incorrect hand movements that may be obvious and occur frequently.


By contrast, case law highlights that the producer can rely on a technically trained operator keeping to the dedicated specifications provided in the operating instructions. Thus, should a kneading machine operator attempt to open the lid seal by heating the modelling clay until excess pressure inside the machine removes the lid, this would be deemed “gross misuse”.

The warning against potential hazards arising from the product should be issued without embellishment at the point at which the user will expect to find it. It would not be right, therefore, to position information about potential product hazards in some hidden location within the operating manual. 

The producer must also take care to ensure that the user of the product understands the operating  instructions. So a significant factor initially is whether the user can actually read and which languages he understands. This immediately implies the question about the languages into which a manual’s safety guidelines should be translated. It goes without saying that the safety guidelines in an operating manual should always be translated into the language of the country in which the product will be sold. The producer cannot assume that the company responsible for international sales of a product in a particular country will also provide an  adequate translation, including that of the relevant warnings, into the respective local language.

Product Liability: Violation of Duty of Care, Design and Manufacturing Defect

Violation of Duty of Care

In line with § 823 of the German Civil Code, case law has categorized the incorrect behavior of a producer (violation of duty of care) into error groups: To differentiate technically between potential defect causation, a distinction is made between four defect groups:

• Design defect
• Manufacturing defect
• Warning defect
• Product monitoring defect

Design Defect
Lawyers talk about a design defect when the whole product line shows the same defect in the technical design. Through organizational means the producer must guarantee compliance with all safety design specifications (e.g. from EC directives) and technical regulations. This will often require material and product tests in accordance with the latest state of scientific and technical knowledge.

 The producer is obliged to design his product in such a way that the average user can use it without risk, in accordance with its stated intended use; any hazards resulting from a foreseeable misuse should also be considered.

For example, in the case of lifts or other means of conveyance, it is important to consider that they will be exposed to a certain amount of overload. For this reason, if the holding ropes on a lift should tear when only slightly overloaded, this would be considered a design defect.

Manufacturing Defect 
Manufacturing defects are characterized by the defective production of individual parts and have nothing to do with the design process; instead they relate to the manufacturing process.

Examples of manufacturing defects: a poorly forged steam trap, a faulty welding seam on the motor, individually occurring material defects on a light grid, incorrect granulate mixture on bimetallic coatings, excessive sputtering on circuit boards.

Outliers present a special case. Outliers are production and manufacturing defects that are unavoidable or undetectable despite all reasonable precautions. Case law introduced a liability exemption for this defect group back in the 50s and 60s; producers are not liable for such outliers in the absence of fault. Nonetheless it is important to stress that liability for outliers still exists under the Product Liability Act because fault plays no role.

Product Liability: Violation of a Protected Right

Compensation can only be claimed under § 823 para. 1 of the German Civil Code if the listed protected right – body, health, property – has been damaged.

From a case law perspective, the affected item does not necessarily have to have been harmed or destroyed for damage to property to have occurred. A restriction of its intended use is sufficient. However, in principle compensation must be paid for destroying other items due to the “producer goods”: By contrast, damage on the actual defective product – a built-in motor catches fire and destroys not only the machine but also itself – will only be compensated under the most limited conditions. This is the case because otherwise the boundary between the purely contractual liability of the seller and the interesting liability in tort of the producer would
become blurred. The details here are very complex and cannot be described within the scope of this Safety Compendium.

 

Liability in Tort and Putting a Defective Product Into Circulation

The wording of § 823 para. 1 of the German Civil Code (BGB) is very wide in scope and establishes producer liability in tort:

“Anyone who, intentionally or negligently, unlawfully injures the life, body, health, property or other right of another person shall be liable to pay compensation to the other party for the resulting damage.”

This general formulation includes liability for damage caused by a defective product at the purchaser’s, end user’s or other third party’s. If you transfer the individual conditions of liability into a structure, you will have the following method of assessment:

1. Act or omission of offender = Putting a defective product into circulation 
2. Physical injury or damage to health, damage to property
3. Physical injury or damage to health/damage to property caused by defective product
4. Illegality
5. Fault (slightest negligence is sufficient!)
6. Legal consequence: Compensation

Putting a defective product into circulation
Liability in tort, as stated in the Product Liability Act, begins when the defective product is put into circulation. Nonetheless, the point at which the product is put into circulation is not defined in law. At the latest therefore, this can be deemed to be when the product appears on the market, but this is not a condition: It is sufficient for the producer to pass the product to another person outside his sphere of producers.

The product is deemed to have been put into circulation when it has been delivered to a sales company which is legally independent of the producer, has been passed to the forwarder or carrier, or the subproduct has been supplied to the assembler. It has not been put into circulation if the product has merely been offered, held in stock or passed to a materials testing laboratory for test purposes.

Product Liability: Distribution of the burden of proof and special features

Distribution of the Burden of Proof

The success of a product liability case depends largely on the burden of production and proof. The underlying principle is that the claimant always has to prove all the foundations of his claim. Under the Product Liability Act, the injured party must prove the defect, the causal relationship between the defect and the damage and the damage itself. It is assumed that the defect was present as the product was put into circulation. The producer is excluded from liability if he can prove that the defect did not exist at the time when it was put into circulation.

Such a circumstance is conceivable particularly in a situation where a sub-product is initially free from defects, but becomes defective due to the specific way in which it is used, i. e. incorporated into the finished product. Take a scenario in which pipes that are intrinsically free from defects but are only suitable for normal pressure loads are built into a machine exposed to high pressure loads without consulting the producer. The producer shall not be liable if the pipes burst due to the high pressure.

Special features of the Product Liability Act

The Product Liability Act provides for a maximum liability payment per claim of EUR 85 million (approx. 109 million USD); a basic amount of EUR 500 (approx. 640 USD) will not be compensated. As such, the injured party shall bear a loss of EUR 500 on the material damage.

Claims under the Product Liability Act fall under the statute of limitations after three years. The limitation period begins from the day on which the plaintiff became aware, or should reasonably have become aware, of the damage, the product defect and the identity of the producer. All claims shall end ten years after the product has been put into circulation.

Product Liability: Importers, Suppliers and Exclusion of Liability

Importer

In accordance with § 4 of the Product Liability Act, the EU importer of the product shall also be liable. The product must be imported into the European Economic Area in the course of the importer’s business activity for commercial purposes (e.g. sale, hire, lease). This regulation is intended to protect the consumer from having to conduct a product liability case with a producer in a third country outside Europe.

For example, if electronic monitoring relays are imported from China and a defect causes a fire, the injured party does not have to conduct a product liability action against the Chinese producer but can turn to the EU importer of the relays as the liable party. By contrast, if the monitoring relays hailed from Italy (i.e. an EU country), the injured party would be expected to initiate proceedings against the Italian producer. Even an action such as this may involve considerable legal and factual difficulties. The court of jurisdiction, in other words the location of the action and the applicable law (Italian or German law) are questions that need to be clarified in advance.

Supplier

The liability of the supplier (agent) in lieu of the producer is limited by the Product Liability Act to those cases in which the producer of the product cannot be identified. If the product user has been harmed by an anonymous product, he can turn to the supplier, which in practice is the seller. However, the supplier shall only be liable in lieu and can discharge himself completely by naming the actual producer or his own supplier within a certain time period.

Exclusion of Liability

No liability for subsequent product improvement:

Any subsequent product improvement will not work retrospectively and render the previous product line defective. In other words, any technical advance in issues of safety shall not retrospectively render the previous model unsafe and therefore defective in the legal sense. However, if fundamental improvements are made to safety, in each individual case each trader must ask himself whether they need to be introduced as soon as possible into his own product segment, in order to comply with the new, modified safety standards. Social acceptance and social safety expectation plays an important role in assessing safety. Product improvements spread quickly, become standards and then become part of the general safety expectation.

An injured party cannot rely solely on the assumption that the product was defective because it was modified by the producer. If the modification is due to the ongoing technical development of the product, the previous model will not be deemed defective. However, if the claimant manages to show and prove that the product was modified purely in order to rectify a fault from a prior existing safety defect, it will be concluded that the defect dates back to the time that the previous product was put into circulation.

No liability for development defect:

From a legal perspective, a development defect is a defect that could not have been detected at the time the product was put into circulation in accordance with the state of scientific and technical knowledge at that time and therefore could not have been avoided. Objectively, a development defect is unavoidable if the  potential hazard from the product could not have been discovered by anyone – either in the relevant industry or at national/international level – because the knowledge was not available at the time the product was put into circulation. The burden of proof is with the producer. As a result, there is barely a case in law in which a producer has really been able to discharge his liability due to the presence of a development defect.

Note: Lawyers and engineers understand something quite different by the term “development defect”: When lawyers talk about a development defect, in the legal sense this corresponds more to a design defect. Caution: Product liability laws in other European states (currently Finland and Luxembourg) also provide for liability for development defects.

Exemption from liability when mandatory regulations are applied:

The producer’s liability to pay compensation is excluded if the defect is due to the product’s compliance with regulations that were mandatory at the time the product was put into circulation. This exemption from liability is fairly insignificant in practice because mandatory regulations for product design are rare in the Federal Republic of Germany. In particular, technical regulations, standards and recommendations (such as DIN regulations, VDE/ ETSI standards or VDE guidelines, VDE recommendations or VCI regulations) are neither statutory nor mandatory. Compliance with technical standards is always voluntary and, what’s more, they are not mandatory laws under the terms of liability exclusion, as this only refers to one binding paragraph in the Product Liability Act.

Product Liability: Producers and Other Responsible Persons

In accordance with § 1 para. 1 of the Product Liability Act, the producer is primarily liable. This is defined as the actual producer of the finished product, component or raw material. The producer usually has a market presence as an AG, GmbH or some other company or corporate form. As a result, the company’s liability is limited.


Assembling and mere product completion
Anyone who assembles the product from parts that other producers have pre-assembled, without any in-house manufacturing (often called an assembler), is also deemed to be the producer. In practice it can be difficult to distinguish between this sort of assembler activity and product completion, which is categorized as a typical agent activity. If a product’s safety-related properties are modified, it can always be assumed that this is the activity of a producer. A relevant pointer is whether the assembly could be achieved by a layperson with no design or technical knowledge, with simple hand movements and without any special tools. Another
relevant factor is whether the assembled product represents a stand-alone product in comparison with the subproducts.


The company that assembles table frames and glass plates into bistro tables should be regarded as a producer and not merely an agent.

By contrast, the company that only apportions and packages a finished product, such as a safety switch or servo amplifier, should not be regarded as a producer.

Liability of the quasi-producer
The quasi- producer is also liable in addition to the actual producer. In accordance with § 4 para. 1 clause 2 of the Product Liability Act, any person who, by putting his name, trademark or other distinguishing feature on the product, presents himself as its producer, shall have legal equality with the producer. This means anyone who presents himself on the market as the actual producer. This liability as quasi-producer has repercussions for mail order businesses and chain stores who have goods manufactured for them and then offer the product with their own trademark or company label. The same applies to industrial suppliers who complete their full range under their own label by purchasing commodities.


The “Produced for …” tag does not justify a status as quasi-producer because the very tag illustrates the point that someone other than the product supplier is the producer. 

It is irrelevant whether it’s the actual producer or the quasi-producer who applies the name,  trademark or any other feature of the quasi-producer to the product. And neither is it necessary for the producer to give his consent before the third party mark is applied. The definitive factor in the liability of the quasi-producer is that the product is put into circulation with the name or trademark of the quasi-producer and with his approval. 

Product Liability Act: Determining the User Circle

In this context, the circle for whom the product is ultimately intended is a key factor. If the product is only intended for a specific user circle, it can be geared towards their safety expectations.
For instance, case law has ruled that the producer cannot assume that wet concrete will only fall into the hands of those who are familiar with the risk of chemical burns from wet concrete. The producer would have to aim at the least informed consumer and so should provide warnings indicating the potential for alkaline chemical burns.

If the product is only to be supplied to a specialist firm, for example, the producer may assume that the products will only be used by specialist staff. However, the picture is quite different if the producer discovers that – despite restrictive sales channels – the product has still found its way into the hands of inexperienced end users (“product migration”).

Product's User Lifecycle

Example: The laser pointer was originally developed for commercial presentation purposes but has since found its way into the daily routine, even being regarded as a toy. Where safety expectation is concerned, the producer must consider the fact that laser beams may potentially be projected into  the human eye. As a result, he must guarantee a higher safety standard than was required for the originally intended application.

However, when certain products are specifically intended for specialists – such as a relay for  electrical engineers for example – and it is clearly stated that the product may only be installed, approved and used by specialist staff, assembly instructions need not be provided for laypeople.

Product Liability: Technical Standards and Specifications

Technical norms, standards and specifications play a role in the legitimate safety expectation from the design and manufacture of products. As a starting point, the product must comply with the current state of research and science at the time it is put into circulation. However, technical specifications and norms merely represent a  minimum standard which, if undershot, might suggest a violation of the expected level of safety. The reverse
conclusion cannot be drawn in this case: A product that complies with the technical standards may nonetheless be defective in the legal sense. Technical standards may have become obsolete or may need expanding due to continued technical developments; they may have been incomplete from the start, or the content may vary from  the current state of scientific and technical knowledge for some other reason. For this reason, in the event of damage in conjunction with a certain product, the position cannot be taken that product defects are excluded in law due to compliance with the designated technical standards. Time and time again the ruling has been that  although compliance with DIN regulations indicates that the product is free from defects, in no way does it exclude the possibility that a product may be defective.


In this context, the Federal Court of Justice (BGH) emphasizes the fact that the “latest state of scientific and technical knowledge” determines the scope of the necessary protection measures. The usual standard in the respective industry is not definitive in this case; instead, alternative technically superior designs must be used by the producer as soon as they are ready for series production and are economically acceptable to the producer.

Examples: A lifting platform may be defective, for example, if it conflicts with the applicable DIN regulations or VDE recommendations and these conflicts cannot be compensated by “more intelligent” solutions.  Neither can the defect be rectified by offering the customer a supplementary set of safety components for purchase.


European standards, such as Annex I of the EC Machinery Directive 98/37/EC, also contain legal technical specifications. If the requirements of European technology law are not met, e.g. in the design of a floor sanding machine, this must be regarded as a product defect. 


However, if a gardening implement meets the existing DIN standards for example, this indicates that it is free from defects but in no way guarantees it. A defect may arise from errors in the technical design if standards have not been implemented or if individual batches suffer from material defects.

Product Liability: Product defects

Under the Product Liability Act, liability shall be accepted for any death, bodily injury, damage to health or material damage caused by the defective product. However, damage to an item used for corporate, business, commercial or professional purposes, cannot be compensated under the Product Liability Act.


Types of product defect:
The “defect” is the key term in the Product Liability Act, as the product defect is the starting point for liability.

§ 3 of the Product Liability Act defines a defect as follows:
“A product is defective when it does not provide the safety which a person is entitled to expect, taking all circumstances into account, including:

• the presentation of the product,
• the use to which it could reasonably be expected that the product would be put,
• the time when the product was put into
  circulation.”

Legitimate safety expectation
It should be noted that nobody can expect one hundred per cent safety. In practical terms it’s important to distinguish between the absolute and relative hazard from a product: Each and every product carries a certain technical hazard potential, depending on its use in a specific case. Ultimately the deciding factor is how dangerous the product is – relatively speaking – compared with other products available on the market.

In other words, absolute safety does not have to be guaranteed. The thinking behind this is that unreasonable costs ought not be imposed on a producer in terms of production. Consequently he is not forced to implement every possible precaution that is technically feasible. The safety standard with which he needs to comply is limited to what is possible and reasonable. A producer must take all due diligence measures that cost less than the total amount of damages avoided by implementing them. As a result, the producer must carefully strike a balance between the threatened damage and the required safety measures.

Example: In the case of a dishwasher, where escaping water could ruin the whole kitchen, it is reasonable to install protection against rust perforation – which is technically feasible and manageable in terms of outlay – even in the face of heavy competition from the market.

The price of the product certainly plays a role in the legitimate safety expectation: The same basic degree of safety may be expected from a cheap product, but not the same overall degree of safety that would be expected from an expensive, highly developed product.

Product Liability Act (ProdHaftG): An Introduction

Strict liability for defective products was introduced universally throughout the whole of the EU through the European Directive 85/374/EEC of 25.06.1985 – the EC Product Liability Directive. This directive was implemented in Germany through the Product Liability Act, which has been in force since 01.01.1990.

§ 1 of the Product Liability Act states:
“If, as a result of a product defect, a person is killed, injured or suffers damage to his health, or an item is damaged, the producer of the product shall be liable to pay compensation to the other party for the resulting damage. In the case of material damage, this rule shall only apply if an item other than the defective product is damaged and this item is normally intended for private use or consumption and has been used by the injured party primarily for this purpose.”

Under the Product Liability Act, liability shall be accepted for any death, bodily injury, damage to health or material damage caused by the defective product. However, damage to an item used for corporate, business, commercial or professional purposes, cannot be compensated under the Product Liability Act.

Example: If a producer’s brass pipe nipples are built into commercially used water pipes and the small  incorporated parts ultimately damage the water pipe as a whole, no compensation claims can be made on the basis of the Product Liability Act. As the water pipe is not an object which is normally intended for private use or consumption, the Product Liability Act does not apply.

An Introduction to Product Liabilty: Terminology

For decades, the German Producer Liability Act has recognized the obligations of (industrial) producers in the field of design, production, instruction and after-sales product monitoring. In 1990, this was joined by the German Product Liability Act, which stems from a Product Liability Directive from Brussels. Today, both systems apply in parallel.

From industry’s perspective, German law essentially distinguishes between contractual and statutory liability: Contractual liability is basically only considered between contractual partners, i. e. in genuine supply relationships. This issue is not dealt with any further here, although there are many pitfalls that await in contracts in cross border business, which would make an early, judicial contractual review seem a recommended course
of action.

We generally talk of the risk from product or producer liability not when it concerns contracts and disputes between suppliers but when it concerns people who assert a claim for damages: Action is brought against a product’s producer due to personal injury or material damage that his product is supposed to have caused (whether or not this is the case is generally decided after a complex process, usually involving a variety of
specialists). The injured party makes a claim against the producer for financial compensation; compensation for non-pecuniary damages may also be involved if there has been damage to health.

Two areas of statutory liability

Statutory liability is again subdivided into two categories: Liability resulting from unlawful acts, known as liability in tort, which is based on an accusation or, in legal terms, on fault. In law, fault is re-described either as “accountability” or with the expressions of guilt: “intent” and “negligence”. If the law allows the mere presence of a certain risk to be enough to justify the producer’s liability (with no interest in the question as to whether at least negligence was involved), we talk of strict liability. This comes into effect much earlier and is
therefore particularly critical for producers.

The above-mentioned liability in tort of the producer is regulated in § 823 of the German Civil Code (BGB); strict liability for defective products comes from the Product Liability Law (ProdHaftG). Its content can only be applied if the accident or damage occurred in Germany. This is also called the “scene of crime principle”. If the accident or damage occurs in a different country, the local liability law will apply in most cases. This
may be more flexible in a particular case, but may also be stricter than German law. In any case it is an unfamiliar law; in incidents abroad such as these, legal advice must be obtained quickly so that mistakes are not made out of pure ignorance.

The section that follows will look first at strict liability from the Product Liability Act and then outline liability in tort. Although in practice both liability principles can usually be applied in parallel, there may be some important differences, particularly with regard to the scope of liability. These will be dealt with separately.

Reaction Times of Safety Functions

Block diagram of safety functions

Several boundary conditions are involved in calculating a safety distance.

Determination of the reaction time in the case of external commands
If an E-STOP pushbutton acts upon an evaluation device, its reaction time is added to the reaction time of the drive-integrated safety function. It will also be necessary to add the time needed to bring an accelerated axis to standstill:

• treac = tmulti + tPMC + tramp
• tmulti = Reaction time of the evaluation device is approx. 20 ms
• tPMC = Reaction time of the drive-integrated safety functions to external signals is 6 ms
• tramp = Ramp time to standstill depends on the moved mass, speed and other application dependent
  data

Determination of the reaction time when limit values are violated

If a monitoring circuit on a drive-integrated safety function is activated, it will be necessary to add the time needed to bring the accelerated axis to standstill. 

• treac = tPMC + tramp

Examples of Safe Motion: Safeguarding Detection Zones with a Safe Camera-Based Solution

Until now, interaction between man and robot has largely been characterized by fixed safeguards. A modern camera-based solution offers a whole range of new options in this case. The detection zone covers all three dimensions; one single device meets every requirement when accessing a danger zone and also provides protection against climbing over and crawling under the detection zone. The detection zones can be individually configured and can also enable the speed of the active axes in the monitored zone to be reduced if anyone approaches.

Structure of the Safety Function

Block Diagram of the Safety Functions

 Determination of the performance level for the overall circuit:
The result is performance level d.

Examples of Safe Motion: Muting with Safe Direction (SDI)

Structure of the Safety Function

The block diagram shows the logical structure of the safety function,
consisting of the series alignment of the safety-related subcircuits (SRP/CS).

In conjunction with light curtains and a muting circuit, the safe direction function (SDI) has a positive effect on safety because the respective direction of the drive axis is monitored during the muting phase and a safe shutdown occurs in the event of an error.

Determination of the performance level for the overall circuit

The performance level corresponds to the result from the example of the safe stop function.

Examples of Safe Motion: Jog Function With Safely Limited Speed (SLS)

These days, jog functions can generally be carried out while guards are open thanks to the safely limited speed (SLS) function. The respective application will determine the type of increment that can be classified as non-hazardous. It may be helpful to consult EN 349 (Minimum gaps to avoid crushing of parts of the human body) and EN 999 (The positioning of protective equipment in respect of approach speeds of parts of the human body).

Structure of the Safety Function

The block diagram shows the logical structure of the safety function,
consisting of the series alignment of the safety-related subcircuits.

Determination of the performance level for the overall circuit
In terms of structure, the jog function with safely limited speed is similar to the safe stop function. The key difference lies in the push buttons used for the jog function and the impact this has on the calculation of the performance level. In EN ISO 13849-1, push buttons (enable switches) are given a B10d of 100 000. The time between two operations (cycles) is the key factor in calculating the MTTFd.

Calculation formula for MTTFd:

The following assumptions are made, based on the application of the component:

• hop is the mean operating time in hours per day
• dop is the mean operating time in days per year
• tcycle is the mean time between the start of two consecutive cycles of the component (e.g. switching a valve) in seconds per cycle

Assumptions:
B10d = 100 000
hop = 16 h/day
dop = 220 d/year

Calculation MTTFd:
tCycle = 5 s ➔ MTTFd = 0.395 years
tCycle = 3 600 s ➔ MTTFd = 284.1 years

As shown in the example with cyclical operation in 5 s intervals, even in the best case it is only possible
to achieve PL c with a B10d value of 100 000. This demonstrates very clearly that the application range for wearing components has a direct influence on the calculation of the performance level and therefore affects the achievable safety level. The design engineer must therefore look very closely at the application range of his components in the respective application. Even if EN ISO 13849-1 states 100 000 cycles for B10d, there may well be special components with a higher B10d value. If an application uses a push button as an E-STOP command device, it will certainly not be operated constantly at 5 second intervals. The situation is completely different if a push button is used as a command device for cyclic initiation of a machine cycle and
has to trigger a safe stop once released. The values stated in the example may cause a problem if a higher performance level is required.