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Safe Methods for Autobody Shop Health SMASH

In October, 2002, the Yale Occupational and Environmental Medicine Program initiated the Safe Methods for Autobody Shop Health (SMASH) study, a NIOSH funded intervention study, with the goal of determining some effective methods of reducing isocyanate exposures to workers in autobody shops. The design of the study, with input from shop owners and managers, required 3 multiday visits with each shop at baseline, 6 months and 1 year.

Hands were wiped to measure contamination.


Fourteen autobody shops were enrolled and randomly divided into a control group and an intervention group. In all shops, information was collected at each visit, including shop equipment available, work practices, respirator fit tests, worker attitudes and knowledge regarding isocyanates, and environmental samples of air (inside and outside of respirator exposures), skin and surface contamination. We also performed a rare field study of the effectiveness of the personal protective equipment, as well as its acceptance by workers.


Study staff worked with shops during one year.

  • A group educational session during work time in the shop, including a 12-minute video called “Safe Work Habits for Limiting Exposures to Hazardous Chemicals” and a question and answer period, was presented to intervention group shops during the first week of the study and to control shops during the 6-month visit.
  • Personal protective equipment recommended by NIOSH for protection against isocyanates (tyvek and coated tyvek coveralls, nitrile gloves, replacement respirator cartridges) and cleaning solutions designed for the removal of isocyanates were provided to the shops monthly for the 6 months following the educational session.
  • The intervention shops were visited monthly for the first 6 months by study staff who observed each worker and provided encouragement to upgrade their work practices.

Thus, the intervention shops were given the educational session, supplies and monthly feedback for the first 6 months, while the control shops were left alone. The control shops were given the educational session and supplies for the second 6 months, while the intervention shops were left alone.


Preliminary results show that:

  • workers increased their use of proper respirators, protective clothing and gloves after the intervention
  • knowledge about auto body safety increased from before to after intervention
  • fit testing pass rates increased significantly after respirator training
  • cleaners already being used in shops and new ones we recommended were equally effective in reducing isocyanate contamination on skin and surfaces
  • visual learning tools, such as the video and posters, rather than printed worker booklets, were preferred for conveying information
  • the most popular components were personal attention from SMASH team members through the work-practice feedback, educational session, personal discussion, and the respirator fit testing and training

Other analyses are ongoing.

Paint curing

We also conducted an experiment and discovered that the isocyanate paints, when “cured” or dry to the touch, may still contain free isocyanates that could cause an immune response.