Use of n-propyl bromide (nPb), also known as 1-bromopropane or 1-BP, has grown considerably over the last 20 years, but that doesn’t mean it is a safe solvent for vapor degreaser parts cleaning. Actually, nPb has gotten more and more press lately advising restrictions of use based on employee exposure limits and confirmed carcinogen classification. These restrictions will lead to an eventual phase-out of n-propyl bromide (nPb) similar to AK225 years ago.
In June 2020, the EPA granted a petition to add nPB to the Clean Air Act list of Hazardous Air Pollutants. According to the Federal Register, this is the first occasion on which the EPA has granted petitions to add a substance to the list of Hazardous Air Pollutants that Congress created in 1990.
This announcement of intention to add nPB to the list of Hazardous Air Pollutants has no immediate impact on regulations. But it is clear that additional regulatory requirements can be expected after nPB is officially added to the list of Hazardous Air Pollutants. As explained in a June 2020 EPA statement, the EPA “may revise air toxic standards for source categories … or add new source categories” for sources of nPB emissions.
Here are summaries to a couple of articles detailing the hazards and toxicity of N-Propyl Bromide which produce cause for nPB replacement solutions:
Dr. David Michaels, assistant secretary of labor for occupational safety and health said “workers exposed to this toxic chemical (nPb) can suffer serious health effects, even long after exposure has ended. Hazardous exposure to 1-BP must be prevented. Employers have a responsibility to ensure the safety of their workers.” The article goes on to mention “Exposure to 1-BP has been associated with damage to the nervous system among workers, and it has been shown to cause reproductive harm in animal studies….The most effective way to protect workers from exposure is to eliminate the use of 1-BP, substituting the chemical with a less toxic substance or less hazardous material.”
In early 2012, the ACGIH released a Notice of Intended Change to reclassify 1-BP as a “Confirmed Animal Carcinogen with Unknown Relevance to Humans” and to lower the TLV-TWA (threshold limit value – time weighted average) from 10 ppm to 0.1 ppm.
A DoD Phase I Impact Assessment for 1-BP identified a high risk to some DoD functions due to worker exposures potentially exceeding the ACGIH’s proposed guideline. Changes to the ACGIH TLV-TWA, as well as the results from the NTP and EPA assessments may prompt revisions in current regulations and promote the development of new regulations.
These new releases and risk alerts gives even more evidence and reason for companies working with advised hazardous solvents such as n-propyl bromide and HCFC225 to look at the extremely safe, environmentally friendly 3M Novec HFE engineered fluids for their precision parts cleaning needs using NESHAP compliant vapor degreasers needs. Be sure that you are safely using solvents to protect yourself and employees.