At a glance
| Substance | Filter type | AirGuard Pro filter |
|---|---|---|
| Hydrogen sulphide | B | AGABEKK1 (A1B1E1K1) |
Hydrogen sulphide: what matters
Hydrogen sulphide is one of the inorganic gases that type B protects against. The instructions for use of the AirGuard Pro filters name it under type B. It often occurs in pits, sewers and confined spaces where oxygen is not certain to be present. Then a filtering respirator is not permitted, an isolating device is needed.
More in the guide: Respiratory protection for gases.
Mask and limits
Under DGUV Rule 112-190 the half mask AG360 is permitted up to 30 times the workplace exposure limit, the full-face mask AG700 up to 400 times. The workplace exposure limit of the substance is given in TRGS 900. The gas filter has its own limit as well: class 1 applies up to 0.1 vol.%, that is 1,000 ml/m³. The stricter value applies.
| Class | Maximum | AirGuard Pro |
|---|---|---|
| Class 1 | 0.1 % by volume (1,000 ml/m³) | AGA1E1, AGABEKK1, AGABEKK1P3 (bayonet) |
| Class 2 | 0.5 % by volume (5,000 ml/m³) | AGA2E2, AGABEK2, AGABEK2P3 (RD40) |
| Class 3 | 1.0 % by volume (10,000 ml/m³) | not in the range |
- Unknown concentration, incident, release: Without a known concentration there is no justified filter choice.
- Oxygen not certain: Filters supply no oxygen, the instructions for use name at least 19.5 vol.%. In tanks, pits and confined spaces an isolating device is needed.
- Filter replacement: Replace gas filters according to a fixed schedule, at the latest at odour, taste or irritation. See Changing filters.
How to proceed
- Read the safety data sheet: components (section 3), boiling point (section 9), workplace exposure limit (section 8).
- Determine type and class: The type depends on the substance, the class on the concentration.
- Risk assessment with the occupational safety specialist, see Respiratory protection duties.
- Check the face seal: a beard or sideburns prevent protection, see Face seal and beards.
If you know substance and concentration, the respirator finder leads to the matching combination. All substances at a glance: Substance directory.
Frequently asked questions
Which filter protects against hydrogen sulphide?
A gas filter of type B (colour grey). With AirGuard Pro these fit: AGABEKK1 (A1B1E1K1). The exact suitability is in the safety data sheet and the instructions for use of the filter.
Is an FFP mask enough against hydrogen sulphide?
No. FFP masks hold back only particles, no gases and vapours. You need a gas or combination filter.
Where do I find the limit value for hydrogen sulphide?
In TRGS 900 (workplace exposure limits) and in section 8 of the safety data sheet. More substance data is in the GESTIS substance database.
Sources
- GESTIS substance database (DGUV, IFA, Germany)
- DGUV Rule 112-190 “Use of respiratory protective devices” (Germany), November 2021 edition
- TRGS 900 Workplace exposure limits (BAuA, Germany)
- Hazardous Substances Ordinance (GefStoffV, Germany)
- Instructions for use and data sheets of the AirGuard Pro products
