A risk assessment consists of a risk analysis and a risk evaluation. A risk analysis identifies hazards and a risk evaluation quantifies the risk(s) arising from these hazards. The term ‘risk analysis’ is often used to mean both hazard identification and risk evaluation.
The approach for identifying hazards varies depending on which ones are being considered.
- For process-related systems, HAZOP (Hazard and Operability) studies are used. This method identifies not only hazards caused by chemical and thermal processes, but also those caused by improper use of the system.
- The machine or combination of all machines are assessed in accordance with SN EN ISO 12100 (Safety of machinery – General principles for design – Risk assessment and risk reduction). This standard provides detailed support in identifying hazards, describes risks that need to be considered by the designer, and contains design principles and a method for constructing safely and reducing risks.
- An analysis of ignition sources is conducted in the field of ATEX (equipment for potentially explosive atmospheres). If equipment or systems are used in potentially explosive atmospheres, they must meet the requirements for the applicable zone. The zones are defined in the explosion protection document. Installations must have the relevant certificates, e.g. type examination certificates. If electrical and/or non-electrical operating equipment is produced, an analysis of ignition sources must be conducted in accordance with Directive 2014/34/EU. This analysis of ignition sources will vary according to zone. Directive 2014/34/EU defines which zones require an analysis of ignition sources.
A risk matrix and risk graph are available for quantitative risk evaluations. These consider the severity of a hazard’s impact and its probability of occurrence.
- For the general classification of risks, we use the risk matrix from Suva (66037.d). We have calibrated it for the process industry.
- Where hazard safeguards come in the form of electrical measures, we use the risk graphs in accordance with IEC 61511 (Functional safety – Safety instrumented systems for the process industry sector) and DIN EN 50156 (Electrical equipment for furnaces and ancillary equipment). This risk graph provides a SIL classification for safety functions.