How to Choose Appropriate Standards for Your Safety Fence

You may feel confused when you choose the proper safety fence since there are a lot of standards that represent so many different fences and accessories. You don’t know which one is applicable in specific zones. However, general standards are always the basic ones for most safety products. EN ISO 12100 and EN ISO 14120 are the typical and authorized standards for reference.

EN ISO 12100: General principles for design - Risk assessment and risk reduction

The standard was defined by the worldwide federation of national standards bodies (ISO member bodies), and it was prepared by Technical Committee ISO/TC 199, Safety of machinery.

For the machine safety industry, ISO 12100 is the “Bible”, which contains all the important definitions, basic rules for selection of safety measures, and detailed instructions for risk assessment.

The primary purpose of this International Standard is to provide designers with an overall framework and guidance for decisions during the development of machinery to enable them to design machines that are safe for their intended use. It also provides a strategy for standards developers and will assist in the preparation of consistent and appropriate type-B and type-C standards.

This International Standard is the basis for a set of standards which has the following structure:

— type-A standards (basic safety standards) giving basic concepts, principles for design, and general aspects that can be applied to machinery;

— type-B standards (generic safety standards) dealing with one safety aspect or one type of safeguard that can be used across a wide range of machinery:
— type-B1 standards on particular safety aspects (for example, safety distances, surface temperature, noise);
— type-B2 standards on safeguards (for example, two-hand controls, interlocking devices, pressure-sensitive devices, guards);

— type-C standards (machine safety standards) dealing with detailed safety requirements for a particular machine or group of machines.

Notes: The requirements of this document can be supplemented or modified by a type-C standard. For machines that are covered by the scope of a type-C standard and that have been designed and built according to the requirements of that standard, the requirements of that type-C standard take precedence.

Normally, the process goes like the following step:

ISO 12100 totally concludes 7 parts, it defines the scope, the normative references, professional terms, definitions, strategy for risk assessment and reduction.

EN ISO 14120: Guards-General requirements for the design and construction of fixed and movable guards, rules for design of safety covers, fences doors etc.

This International Standard is a type-B2 standard as stated in ISO 12100. Guards provide a risk reduction for both protection against unintended access and against ejected parts and substances. The guarding can also give protection against other hazards, e.g. noise, fire, biological hazards, and radiation.

ISO 12100 defines the applying scope, risk assessment, general requirement for the design and construction of guards, selection of types of guards, and verification of the safety of requirements for guards.

Besides, there are standards available for specific applying zone.

EN ISO 14119: Safety of machinery — Interlocking devices associated with guards — Principles for design and selection
EN ISO 13857: Safety of machinery — Safety distances to prevent hazard zones being reached by upper and lower limbs-Determines height of fencing, size of access openings, and corresponding safety distances
EN ISO 13855: Safety of machinery — Positioning of safeguards with respect to the approach speeds of parts of the human body
EN ISO 13854: Safety of machinery — Minimum gaps to avoid crushing of parts of the human body
EN ISO 13851: Safety of machinery — Two-hand control devices — Principles for design and selection (previously EN 574)
EN ISO 14118: Safety of machinery — Prevention of unexpected start-up
EN ISO 13850: Safety of machinery — Emergency stop function — Principles for design
EN ISO 13849-1/-2 : Safety of machinery — Safety-related parts of control systems Basics for design of reliable control circuits such as for door interlocking and monitoring, formulas and methods, part 2 covers verification and validation of safety systems
EN ISO 14122-3: Safety of machinery — Permanent means of access to machinery — Part 3: Stairs, stepladders and guard-rails
EN ISO 14159: Safety of machinery — Hygiene requirements for the design of machinery
EN ISO 11161: Safety of machinery — Integrated manufacturing systems — Basic requirements
EN 60204-1: Electrical equipment of machines - Part 1: General requirements The electrical safety “Bible” for machine manufacturers