Section 7-2. Recirculation of air in ventilation systems

Recirculation of air is only permitted if the employer can document that it does not entail a health risk for the employees.
Ventilation that entails recirculation of air containing carcinogenic, mutagenic or reproductively harmful chemicals or air from premises where hot work is carried out is not permitted.
The prohibition on recirculation does not apply to work where wood dust is released.