Respiratory protection for hydrochloric acid (hydrogen chloride): filter type E

At a glance

Hydrochloric acid (hydrogen chloride): what matters

Hydrochloric acid releases hydrogen chloride, an acid gas. Type E protects against it, named in the instructions for use of the AirGuard Pro filters for hydrogen chloride and other acid gases. Irritating gases attack eyes and mucous membranes, so the full-face mask makes sense. Never mix acid and chlorine-containing cleaners: chlorine gas is released.

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.

• 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

1. Read the safety data sheet: components (section 3), boiling point (section 9), workplace exposure limit (section 8).
2. Determine type and class: The type depends on the substance, the class on the concentration.
3. Risk assessment with the occupational safety specialist, see Respiratory protection duties.
4. 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.