Do all air compressors used to supply breathing air have to have a carbon monoxide alarm?

A compressor that is not oil-lubricated is not required to have an alarm. However, an employer must ensure that carbon monoxide levels in the breathing air do not exceed 10 ppm. Methods for ensuring that the carbon monoxide level does not exceed 10 ppm include the placement of the air intake for the compressor in an area known to be free from contaminants, frequent or continuous monitoring of the breathing air supply, the use of carbon monoxide filters, or the use of high temperature alarms or shut off devices where necessary.

For an oil lubricated air compressor, carbon monoxide can be produced where oil enters into the compression chamber and is partially combusted. Carbon monoxide can also enter the air intake for the compressor if the intake is not properly located. This type of compressor must have either a carbon monoxide alarm, high temperature alarm, or both. If only a high temperature alarm is used then the breathing air must be tested for the presence of carbon monoxide at intervals sufficient to ensure that carbon monoxide levels do not exceed 10 ppm.