Risk Reduction; Residual Risk; Machine Safety In The Usa; Minimum Requirements Of The Osha - Siemens SINAMICS V90 Operating Instructions Manual

Safety Integrated function
8.1 Standards and regulations
8.1.2.8

Risk reduction

Risk reduction measures for a machine can be implemented by means of safety-related
control functions in addition to structural measures. To implement these control functions,
special requirements must be taken into account, graded according to the magnitude of the
risk. These are described in EN ISO 13849-1 or, in the case of electrical controllers
(particularly programmable electronics), in EN 61508 or EN 62061. The requirements
regarding safety-related controller components are graded according to the magnitude of the
risk and the level to which the risk needs to be reduced.
EN ISO 13849-1 defines a risk flow chart that instead of categories results in hierarchically
graduated Performance Levels (PL).
IEC/EN 62061 uses "Safety Integrity Level" (SIL) for classification purposes. This is a
quantified measure of the safety-related performance of a controller. The required SIL is also
determined in accordance with the risk assessment principle according to ISO 12100 (EN
1050). Annex A of the standard describes a method for determining the required Safety
Integrity Level (SIL).
Regardless of which standard is applied, steps must be taken to ensure that all the machine
controller components required for executing the safety-related functions fulfill these
requirements.
8.1.2.9

Residual risk

In today's technologically advanced world, the concept of safety is relative. The ability to
ensure safety to the extent that risk is ruled out in all circumstances – "zero-risk guarantee" –
is practically impossible. The residual risk is the risk that remains once all the relevant
protective measures have been implemented in accordance with the latest state of the art.
Residual risks must be clearly referred to in the machine/plant documentation (user
information according to EN ISO 12100-2).
8.1.3

Machine safety in the USA

A key difference between the USA and Europe in the legal requirements regarding safety at
work is that, in the USA, no legislation exists regarding machinery safety that is applicable in
all of the states and that defines the responsibility of the manufacturer/supplier. A general
requirement exists stating that employers must ensure a safe workplace.
8.1.3.1

Minimum requirements of the OSHA

The Occupational Safety and Health Act (OSHA) from 1970 regulates the requirement that
employers must offer a safe place of work. The core requirements of OSHA are specified in
Section 5 "Duties".
The requirements of the OSH Act are managed by the "Occupational Safety and Health
Administration" (also known as OSHA). OSHA employs regional inspectors who check
whether or not workplaces comply with the applicable regulations.
The OSHA regulations are described in OSHA 29 CFR 1910.xxx ("OSHA Regulations (29
CFR) PART 1910 Occupational Safety and Health"). (CFR: Code of Federal Regulations.)
http://www.osha.gov
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SINAMICS V90, SIMOTICS S-1FL6
Operating Instructions, 09/2016, A5E36037884-002