Unless the employer clearly demonstrates by other means of evaluation that, in accordance with paragraph 2, adequate prevention and protection have been achieved, the employer shall carry out on a regular basis, and when any change occurs in the conditions which may affect workers' exposure to chemical agents, such measurements of chemical agents which may present a risk to worker's health at the workplace as are necessary, in particular in relation to the occupational exposure limit values.
Razen če delodajalec z drugimi sredstvi vrednotenja jasno pokaže, da je bilo v skladu z odstavkom 2 doseženo ustrezno preprečevanje in varovanje, mora delodajalec redno in ob katerikoli spremembi pogojev, ki lahko vplivajo na izpostavljenost delavcev kemičnim snovem, izvajati potrebne meritve kemičnih snovi, ki so lahko nevarne za zdravje delavcev na delovnem mestu, posebno v zvezi z mejnimi vrednostmi za poklicno izpostavljenost.