Worker exposure to 1-bromopropane (1-BP), a toxic chemical associated with nervous system damage and reproductive harm in animal studies, has prompted a joint hazard alert from the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH).
Both agencies are urging employers to take appropriate steps to protect workers from exposure to 1-bromopropane (also known as n-propyl bromide or nPB), a solvent used in a variety of industrial applications.
“The use of 1-bromopropane has increased in workplaces over the last 20 years,” says OSHA Administrator Dr. David Michaels. “Workers exposed to this toxic chemical 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.”
1-BP is used in:
Vapor and immersion degreasing operations for cleaning metals, plastics and electronic and optical components,
Adhesive spray applications,
Dry cleaning, and
Solvent sprays used in operations such as asphalt production, aircraft maintenance and synthetic fiber manufacturing.
The hazard alert was issued in response to information on the increased use of 1-BP as a substitute for other solvents within the past 20 years, as well as recent reports of overexposure in furniture manufacturing.
Workers may be exposed to 1-BP by breathing in vapors or spray mists and by absorption through the skin if the chemical touches the skin. Exposure to 1-BP can irritate workers’ eyes, mucous membranes, upper airways and skin, along with causing neurological symptoms such as headaches, dizziness, loss of consciousness, slurred speech, confusion, difficulty walking, muscle twitching and loss of feeling in arms and legs.
These effects may continue even after exposure to 1-BP has ended. Health impacts of 1-BP exposure may be seen in exposures of as little as two days. NIOSH and OSHA say that workers reporting health effects after being exposed to 1-BP should be referred to a doctor or nurse with occupational or environmental medical expertise.
OSHA does not currently have a specific exposure standard for 1-BP, although employers are required by law to keep their workers safe from this recognized hazard. Degreasing, spray adhesive, aerosol solvent and dry cleaning operations expose workers to air concentrations of 1-BP which exceed the American Conference of Governmental Industrial Hygienists’ (ACGIH) current 10 parts per million time-weighted average threshold limit value. ACGIH recently proposed lowering that exposure limit to 0.1 PPM.
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. However, NIOSH and OSHA caution that replacement chemicals may still pose associated health hazards that need to be considered and controlled.
Engineering controls to reduce worker exposure to 1-BP include:
Isolating machinery using 1-BP from other work areas,
Installing local exhaust ventilation and following a routine maintenance schedule to ensure that ventilation equipment is performing effectively.
Automatically controlled hoists and sliding or rolling covers, and efforts to ensure the effectiveness of cooling coils in workplaces using vapor degreasing systems.
A qualified technician managing the conversion of machines that previously used a different solvent in dry cleaning operations. Machine features helpful in reducing 1-BP exposures include safety switches, safety interlocks, filtration systems, filling devices, the use of gaskets and seals resistant to 1-BP, and process controls.
Suggested administrative controls to reduce 1-BP exposures include:
Reducing the amount of time that a worker is exposed to 1-BP as well as reducing the number of workers exposed to the chemical,
Purchasing, storing and using the smallest possible amount of this solvent,
Keeping 1-BP containers closed between uses, and
Avoiding overheating the solvent in dry cleaning operations and also shortening drying periods.
Personal protective equipment (PPE) should be used when engineering controls are being installed or repaired, when engineering and administrative or work practice controls are not effective in adequately reducing exposure, or when controls are not feasible.
Respiratory protection for workers exposed to 1-BP should include having a written respiratory program, proper respirator selection and maintenance, fit testing, medical evaluations, cartridge change schedules, a program administrator and providing worker training.
Skin PPE should include chemically protective gloves (supported polyvinyl alcohol or multiple-layer laminates), arm sleeves, aprons and other appropriate clothing.