Estimating worker reentry times following application of two generic spray polyurethane foam formulations according to ASTM Standard Practice D8445-22a

The ASTM D8445-22a Standard Practice for Measuring Chemical Emissions from Spray Polyurethane Foam (SPF) Insulation Samples in a Large-scale Ventilated Enclosure establishes procedures for measuring chemical emissions of volatile and semi-volatile organic compounds (VOCs and SVOCs) from spray polyurethane foam (SPF) insulation samples. This standard practice can be used to identify chemical emissions during SPF application and for three days following application. The goal of the D8445-22a is to generate chemical emissions data that can be used for research activities, modeled, and/or used as a basis for recommending reentry and re-occupancy times following the application of SPF in residential or commercial buildings. Potential reentry and re-occupancy times only apply to applications that meet the manufacturer's guidelines and are specific to the tested formulation. The purpose of the study was to demonstrate how data collected in accordance with the ASTM standard practice may be used by health professionals to recommend a time for unprotected trade workers to be restricted from entry into affected work areas following SPF application. Chemical emissions from two generic, high-pressure, open-cell formulations were evaluated in a ventilated enclosure. One SPF formulation contained emissive catalysts, and the other formulation, non-emissive catalysts. Exhaust ventilation was supplied to the enclosure at a rate of 10 Air Changes per Hour (ACH) for 2 hr during and post SPF application. The air change rate was then lowered to 0.3 ACH for the remainder of the test period. Chemical components selected for evaluation represent those typically present in SPF formulations and include methylene diphenyl diisocyanate (MDI), amine catalyst, aldehydes, and flame retardant.