Question

head protection is mandatory. some types of head protection: hard hat or safety helmet offers protection against falling objects or impact. protective cap protects against small impacts, but not against falling objects. service life a hard hat has a service life of 5 years, on average. this depends on its material. the service life can also be shortened by: chemicals direct sunlight climate the user manual states the maximum service life. extra features a hard hat often offers the possibility to fit a face visor and/or ear defenders. these can protect you against noise and splashed liquids. note:never use a hard hat that has been deformed by a falling object. what has an influence on the aging process of a safety hard hat? climate. the material. direct sunlight. chemicals

Explanation:

The text states that the service - life of a hard hat (safety hard hat) can be shortened by chemicals, direct sunlight, and climate. Also, it mentions that the service - life depends on its material. These factors influence the aging process of the safety hard hat.

Answer:

Climate, The material, Direct sunlight, Chemicals