Abstract
Controlled foam-spraying experiments conducted in a sealed, unventilated room were designed to evaluate the influence of formulations and application techniques on atmospheric contamination with isocyanates. The conditions for sampling the atmosphere during application of formulations involving TDI (toluenediisocyanate) and MDI (methylenebis(4-phenylisocyanate)) are described in detail. The Elastomers Laboratory spray gun, which mixes the chemicals internally, is compared to a conventional external-mix spray gun. Equipment for quantitative measurement of TDI and MDI retained by activated charcoal canisters is described, and results are given. Recommendations of the safest method of foam spraying, based on information acquired and safety precautions, including the use of operator protection equipment, are discussed.