Compressed Breathing Air Cylinders

Cylinders that are used to supply breathing air to respirators must be tested and maintained according to 49 CFR Part 180. The quality of the cylinders should be ensured by a certificate of analysis from the supplier. The moisture content in the cylinder must not exceed a dew point of minus 50 degrees Fahrenheit at normal atmospheric pressure. The employer may only use a respirator manufacturer's NIOSH-approved cylinders.

Compressed breathing air cylinders should be built and maintained to meet the following requirements:

• They must prevent entry of contaminated air into the air-supply system.
• They must minimize moisture content so that the dew point at normal atmospheric pressure is 10 degrees Fahrenheit below the ambient room temperature.
• They must contain appropriate filters to further ensure breathing air quality (the filters should be replaced or refurbished according to the manufacturer instructions).
• They must have a tag that contains the most recent change date and the signature of the person who changed out the cylinder. This tag should be kept with the canister.

To learn more about Respiratory Protection visit our Cal/OSHA Respiratory Protection Online Training web page.