NIOSH to Manufacturer: Improve Ventilation, Metalworking Fluid Maintenance

Published September 16, 2015

During a Health Hazard Evaluation at an aircraft ejection seat manufacturer, NIOSH staff found a methoxypyrazine, a chemical that can be produced by bacteria, to be the likely cause of a lingering unpleasant odor. Investigators found 2-methoxy-3,5-dimethylpyrazine (3,5-MDMP) in the air and in the metalworking fluid at the facility. Their analysis of air and bulk metalworking fluid samples identified bacteria belonging to the same order that produce 3,5-MDMP. According to the NIOSH report, the same bacteria may be contributing to the high concentrations of endotoxin that were also found in the metalworking fluid.

Air samples from the facility indicated metalworking fluid mist in the air, including in areas outside of where the fluids are used, as well as methyl ethyl ketone, styrene, and other volatile organic compounds (VOCs). The NIOSH report states that these chemical and biological contaminants and odors may have contributed to the health symptoms reported by employees, which include fatigue, headache, eye irritation, runny nose or congestion, and cough.

NIOSH staff found that the ventilation and water diversion systems at the manufacturing facility were not well maintained. The agency recommends decontaminating the metalworking machines and improving metalworking fluid maintenance and ventilation to improve health and safety at the facility.

Specific recommendations include:

  • Modify the facility ventilation systems to incorporate outdoor air supply to the paraloft, component repair, document control, and inspection departments
  • Repair the roof, gutters, and downspouts to ensure water is diverted away from the building
  • Increase the height of the exhaust fan units above the roofline to decrease the likelihood of re-entrainment of building exhaust air
  • Implement maintenance programs for managing metalworking fluid in the machines and recycling system

For more information, see the NIOSH report (PDF). More Health Hazard Evaluation reports are available on NIOSH’s website.