Evaluation of the OSHA 42 and NIOSH 5521 Methods in Determining the Free Isocyanate Concentration in Aerosols and Vapor Phases During Application of Two Component 1, 6 - Hexamethylene Diisocyanate Paints
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
When sampling for isocyanates, the two currently recommended methods OSHA 42 and NIOSH 5521 have limitations that cause under estimation of the isocyanate concentration reported. During spray painting operations, isocyanate is present in both aerosol and vapor forms. When the NIOSH method is used the midget impinger inlet and outlet nozzles tend to plug as paint particles collect there during sampling. As the outlet nozzle opening becomes smaller, the velocity of the sampling stream increases causing particles to pass through the derivatizing agent without capture. Both phenomena result in underestimation of aerosol content of the sampled air.
- Organic Chemistry
- Physical Chemistry
- Coatings, Colorants and Finishes