Understanding Safety Regulations and Standards
Regulators around the globe agree on one thing: safety systems should use suitable technical equipment to keep potential hazards from both people and the environment without restricting industrial production. When accidents are minimized with minimal impact on output, productivity should rise.
But that’s where the agreement ends. There are different concepts and requirements to guarantee safety in the various regions and countries around the globe. For example, in the European Union, there are requirements placed both on the manufacturer of a plant or system as well as the operating company, which are regulated by a range of European directives, laws and standards.
On the other hand, requirements in the U.S. differ both at a regional and even at a local level. However, throughout the USA there is a basic requirement that an employer must guarantee a safe place of work. In the case of damage, as a result of the product liability laws, a manufacturer can be made liable for damage caused by his product. In other countries and areas, regional requirements apply.
Knowing which regulations apply is a critical step. It’s important for machinery manufacturers and plant construction companies to know that the legislation and rules of the location where the machine or plant is being operated always apply. For instance, the control system of a machine operated and used in the US must fulfill US requirements even if the machine manufacturer (i.e. the OEM) is based in Europe.
In the area of machine safety, EN ISO 13849 (derived from EN 954) and IEC 62061 specifically address the requirements placed on safety-related control systems and therefore concentrate on functional safety. The measure of achieved functional safety is the probability of the occurrence of dangerous failures. Various levels are required, which determines degree of fault tolerance and the quality that should be guaranteed by avoiding systematic faults. Various terminology is used to express this. In IEC 61508: “Safety Integrity Level” (SIL) and EN ISO 13849-1 “Performance Level” (PL).
Standards ensure safety
By maintaining and fulfilling the machine safety standards, it can be ensured that state-of-the-art technology is achieved – therefore ensuring that a company, erecting a plant or a manufacturer producing a machine or a device has done their due diligence for ensuring safety.
If there are no harmonized European standards, or they cannot be applied for specific reasons, then a manufacturer can apply national standards. By applying ratified (EN) standards, the manufacturer can prove that recognized state-of-the-art technology was fulfilled. However, when such standards are applied, this does not automatically represent a presumption of conformity for a harmonized standard.
US machine safety standards
Understanding machine safety standards and terms remains a challenging first step to spotting and reducing risks, which can lead to increasing profitability. There are many sources for help. U.S. organizations with machine safety standards include American National Standards Institute (ANSI), National Fire Protection Association (NFPA), Robotics Industries Association (RIA), and U.S. Occupational Safety & Health Administration (OSHA), among others.
NFPA 70 predominantly applies to buildings, but also to the electrical connections of machines and parts of machines. NFPA 79 applies to the electrical equipment of industrial machines or a group of machines with rated voltages of less than 600 V.
NFPA 79 since 2002 ushered in many changes, for example requirements for software- and firmware-based controllers performing safety-related functions, 2007 for fail-safe drives and 2012 includes wireless safety controls.
The ANSI B11 standards series have other machine safety standards integrated, which have been developed by associations e.g. the Association for Manufacturing Technology (AMT), National Fire Protection Association (NFPA) and the Robotic Industries Association (RIA). Also there exists a memorandum of understanding between ANSI and OSHA that allows ANSI to use its technical resources to assist OSHA in carrying out its responsibilities.
One key requirement of all the machine safety standards is that they must provide protection equivalent to that of hardwired or hardware control systems. Programmable systems must have safe shutdowns that don’t cause the loss of the safety-related function(s).
Over the past few years, risk analysis has become a requirement for assessing the hazards that a machine presents. By their nature, both machinery and plants represent potential risks. Therefore, new machine safety standards like the NFPA 79, 2012, ANSI/RIA 15.06 require a risk assessment for every machine. A suitable safety technology/system can be selected using the documented results of a risk analysis – based on the specified safety level of the particular application.
The following standards should be applied for the techniques to evaluate and assess these risks:
• For Europe:
EN ISO 12100 “Safety of machinery – basic terminology, general principles for design – risk assessment and risk reduction”.
• For USA:
ANSI B11.0 – 2012, Safety of Machinery; General Requirements and Risk Assessment
This standard applies to new, modified or rebuilt power driven machines, not portable by hand, used to shape and/or form metal or other materials by cutting, impact, pressure, electrical or other processing techniques, or a combination of these processes.
Risk reduction, an ongoing process, is needed so that any remaining hazards are within tolerable levels.
Safety standards reduce operating costs
Numerous safety research studies, customer application case studies and testimonies show a focus on how safety protects plant personnel and increases productivity. Companies that implement safety functions, perform functional safety evaluations, and implement safety in manufacturing processes by following machine safety guidelines are finding benefits on the bottom line, with a cost saving of at least 30%.
Other financial benefits come when companies implement safety standards. One is global acceptance, because more global opportunities open up. Another important one is that insurance companies have started to recognize machine safety compliance, which can reflect favorably on the insurance premiums.Have an Inquiry for Siemens about this article? Click Here >>