2.21.5. The employer must reduce the workers’ daily exposure to noise, in accordance with section 2.21.6, or provide them with hearing protectors in accordance with the rules established in section 2.21.10,(1) during the time needed to implement a reasonable measure;
(2) during the time needed to repair or maintain a machine or piece of equipment;
(3) when it is not possible to respect the exposure limits; or
(4) in the situations referred to in section 2.21.7.