Section 8-3. Measures to deal with low oxygen concentrations, and hazardous and flammable gas concentrations

If it is necessary, in connection with inspections or other work of short duration at wastewater treatment plants, to enter spaces that contain hazardous gases, where the oxygen concentration is too low or where there is a risk of explosion, no work shall be carried out over and above what is strictly necessary. No work shall be carried out that can cause fire or explosion. Tools and aids shall be of a non-sparking material.
Supplied air respirators and a lifeline and harness shall be worn for such work. Where there is no risk of flammable gases or too low oxygen concentrations, other respiratory protection equipment that provides satisfactory protection against the hazardous gases in question may be used.
If the pool is covered to prevent pollution because of air supply or another process, and it is necessary to open the cover to carry out work in the pool, the air supply shall be stopped and, if necessary, temporary guard rails shall be installed.