1-Bromopropane is an organobromine compound with the chemical formula CH3CH2CH2Br. It is a colorless liquid that is used as a solvent. It has a characteristic hydrocarbon odor. Its industrial applications increased dramatically in the 21st century.
Like many other liquid halocarbons, 1-bromopropane finds use as a liquid or gaseous solvent. It is a solvent for adhesives in aerosol glues that glue foam cushions together. It is a solvent in asphalt production, in the aviation industry for maintenance, and in synthetic fiber production. It is a solvent for degreasing plastics, optics and on metal surfaces, to remove soldering residues from electronic circuit boards. Its increasing use in the 21st century resulted from the need for a substitute for chlorofluorocarbons and perchloroethylene as a dry cleaning solvent.
In 2003, the American Conference of Governmental Industrial Hygienists set the time-weighted average threshold limit value for an 8-hour exposure at 10 parts per million. In 2014, the ACGIH adopted a lower threshold limit value of 0.1 ppm as an 8-hour time-weighted average. The California Occupational Safety and Health Administration set the permissible exposure limit at 5 ppm in 2010. Though symptoms of overexposure can begin within 2 days of exposure, typically long-term exposure is more harmful. In 2008, the U.S. CDC recommended that use of 1-bromopropane as a replacement for perchloroethylene may require adjustment and modification of equipment, improved ventilation, and use of personal protective equipment. In 2013, a peer-review panel convened by the U.S. National Toxicology Program unanimously recommended that 1-bromopropane, be classified as reasonably anticipated human carcinogens. Extended occupational exposure to 1-bromopropane in higher concentrations than recommended has resulted in significant injury to workers in the United States. Its use as a solvent in aerosol glues used to glue foam cushions has been especially controversial. Reported symptoms of overexposure affect the nervous system and include confusion, slurred speech, dizziness, paresthesias, and difficulty walking, unusual fatigue and headaches, development of arthralgias, visual disturbances, and muscle twitching. Symptoms may persist over one year. Other symptoms include irritation of mucous membranes, eyes, upper respiratory tract, and skin, as well as transient loss of consciousness. Loss of feeling in the feet, an example of paresthesia, is colloquially called "dead foot" by workers who suffer from it. Of nationwide "more than 140 cushion workers nationwide, mostly from plants in Utah, Mississippi and North Carolina, that had been exposed to dangerous levels of the chemical, many of them sickened and unable to walk". One worker's long-term exposure resulting in neurological damage was covered in the NY Times. Air sampling for the level of 1-bromopropane and monitoring workers' urine for metabolites are both effective at measuring workers' exposure. Occupational exposure to 1-bromopropane typically occurs through breathing or skin contact; it is easily absorbed into the blood via the skin. Replacing 1-bromopropane with water or acetone-based adhesives is the preferred NIOSH option for controlling occupational exposure, but other options include engineering controls like isolation and ventilation, administrative controls, and PPE that includes respiratory and skin protection. 1-Bromopropane can penetrate most gloves, but not those made of polyvinyl alcohol or laminates.
Animal studies
Animal studies of 1-bromopropane have showed that it is a carcinogen in those models. Rodents exposed to 1-bromopropane developed lung, colon, and skin cancer at higher rates.
Environmental impact
Although 1-bromopropane is naturally produced, it is one of the very short-lived substances ozone depleting chemicals.
