EN 355: Personal protective equipment against falls from a height - Energy absorbers 

EN 355:2002 describes the requirements, test methods, marking, manufacturer information, and packaging specifications for energy absorbers. Energy absorbers in conformance with this European Standard are components of, or used in combination with, lanyards, anchor lines, and full body harnesses. The combination of an energy absorber and a lanyard constitutes one of the fall arrest systems detailed in EN 363 and, when combined with a full body harness, among those systems described in EN 361. In addition, EN 353-1, EN 353-2, and EN 360 pertain to fall arrest devices. 

If a user falls while connected to a 2m long textile lanyard without an energy absorber, the force on the user and the anchor would be unacceptably high. Therefore, every fall arrest system must be equipped with an energy absorber to limit the impact force to 6kN. 

EN 355:2002
Shock absorbing lanyards
Lanyards intended for use in connecting the attachment point of a full body harness to a secure anchorage device must include a shock-absorbing component that reduces the force applied to the wearer by gradually arresting their fall. In the event of a fall, shock absorbers should limit the impact force to a maximum of 6kN. 

Dynamic Performance
Shock absorbing lanyards are subject to a drop test to assess the lanyard’s capacity to arrest a fall within a maximum distance while limiting the arrest force to an acceptable range. The lanyard should not deploy (i.e., stretch, open, tear) beyond a maximum length of 1.75m, with a maximum force of 6 kN, when supporting a 100kg solid mass released over a distance that is twice the lanyard’s length. Energy absorbers that are sold separately (e.g., as components) must be extended with a chain to a length of 2m and tested using a mass released over a distance of 4m.

Static Strength
Energy absorbers are subjected to a 15 kN tensile force. Tensile forces are applied and held for at least 3 minutes to ensure that the product’s breaking strength exceeds the force specified in the standard.

Corrosion Resistance
Metallic components used in fall protection equipment are subjected to a neutral salt spray test to determine whether the product can provide a minimum resistance to environmental corrosion (e.g., rust). Products are held in a sealed chamber filled with a saltwater mist, which can cause untreated metals to rust. Products are subjected to either 24 or 48 hours of exposure and examined thereafter for signs of rust and to assess whether each device can continue to function properly.