Essentially Minimum Requirements

At almost every meeting (conference, training session, etc.) dedicated to machine safety, where PIP (Polish H&S surveillance body) is involved, an obligatory item on the agenda is a chart illustrating the relationship between minimum and essential requirements. It’s like there was an initial chaos, then essential safety requirements were introduced for newly produced machines, and for old machines, manufactured or imported earlier (before 1993 in the „old” EU, before 2004 in Poland, before 2013 in Croatia), there are these so-called minimum requirements, a sort of „better then nothing” approach.

If the minimum requirements actually apply only to old machines, meaning that the problem will soon disappear on its own as the number of old machines decreases, then why keep talking about it all the time?

Intellectualizing the Matter

In the strict sense, the so-called „minimum requirements,” or „minimum requirements for the safety and health of workers using work equipment,” are Annex I to Directive 2009/104/EC, also known as the Equipment Directive, ED.^[1]The directive is to be implemented in each member state by the appropriate regulations, but it is not of great significance because directives are binding on member states, and any citizen who … Continue reading

On the other hand, the so-called „essential requirements,” or „essential health and safety requirements relating to the design and construction of machinery,” are — in the strict sense — Annex I to Directive 2006/42/EC, also known as the Machinery Directive, MD.

In the strict sense, therefore, Annex I to the MD applies only to machines manufactured before the Polish (well, can be different in other countries) accession to the EU; all machines produced or imported into the EU in 2004 or later are subject to the requirements set out in Annex I to the MD.

However, it can be noticed that the „minimum” and „essential” requirements often refer to the entire acts that introduce these requirements, namely directives. And ED is still applicable — not only to „old” machines. However, ED applies to users of machines, while MD applies to manufacturers of machines. ^[2]Manufacturers are usually also users of machines and therefore they are also subject to ED requirements. Taking into account the dates of production (or import) of the machine, the whole puzzle looks as follows:

Machines manufactured before 1st May 2004

Manufacturers — no requirements.^[3]Some requirements have always existed, of course, but we are now referring only to DN and DM.

Users — DN.

Machines from 1st May 2004 and newer

Manufacturers — DM.

Users — DN, but instead of Annex I, there is Annex I to DM.

Simple, isn’t it?

But…

The „essential” requirements, namely Annex I to DM, although detailed (30 pages of text in the Polish version), only provide general indications. Let’s take an example provision regarding guards: „they must be placed at an appropriate distance from the danger zone.” What distance is considered „appropriate”? Another requirement concerning protective devices states that they should be designed in such a way that „persons cannot access moving parts.” How can they „not access” them when protective devices do not restrict the movements of the operator? Lastly, there is a completely utopian requirement that the machine should be designed „in a way that prevents or allows prevention of all electrical hazards”.

Bureaucrats wrote them, and politicians enacted regulations to sound nice. And now they have to be applied somehow, preferably while allowing production.^[4]Because both bureaucrats and politicians need something to drink and snack on, and unfortunately, the money for that comes only from work. The proper interpretation of all these requirements is determined by the standards so-called harmonized with MD. Standards are approved for application by the European Commission, but their content is essentially determined by people who know something about the subject, so it somehow works. For example, a regulation states that all electrical hazards should be eliminated, and a standard ^[5]EN 60204-1:2018 Safety of machinery. Electrical equipment of machines. General requirements specifies that this can be achieved by ensuring the electrical cabinet is sealed to IP2X level, meaning that the openings are no larger than 12.5 mm.

The „minimum” requirements do not refer to harmonized standards, and there is no such thing as a standard harmonized with ED. So, how should we understand the requirements stated there, which are inherently even more general than those in MD? What does it mean that „control systems must be safe and must be selected with due consideration of failures”? If machines „must be equipped with (…) devices that (..) prevent movements of dangerous parts before reaching the danger zone” — how do we determine the time it takes to reach the danger zone?

The answer can be found in Directive 89/391/EEC,^[6]directive on the introduction of measures to improve the safety and health of workers at the workplace which states that one of the general principles of safety that employers should apply is „adaptation to technical progress”.^[7]6.2.e When seeking a benchmark for such progress in the field of machine safety, it is hard to find a more reliable source than the standards harmonized with MD.

Let’s take an industrial robot as an example. Until 2006, EN 775:1992 was in effect, which stated that a robot should be equipped with an „enabling device”. Period. And indeed, in older robots, one could find an enabling device in the form of a button that, when released, would stop the robot in teach mode. Today, ISO 10218-1:2012 specifies that the enabling device should have three positions, with only the middle position allowing movement, and full depression requiring complete release and then pressing it back to the middle position in order to restart the device. Today, this is an „obvious obviousness” for everyone. If an accident were to occur on such an old robot manufactured before 2004, caused in part by the operator tightly gripping the button instead of releasing it when faced with a danger, would a court consider the machine adequately protected because different rules were in place when it was produced?

Back to the Reality

Formally, the regulations can be somewhat convoluted because there are separate directives for manufacturers and users (and parts of one directive are applied instead of parts of the other), in addition to national implementing regulations. However, the assessment of machine risk ultimately boils down to the same thing, whether conducted by the manufacturer or the user: examining compliance with the standards harmonized with MD.

Image by David Bawm from Pixabay. Translated with Aria.