Modeling of hexamethylene diisocyanate and psychrometric parameters and other effective factors in the polyurethane factories

Background: Diisocyanates are widely used in surface coatings, polyurethane (PUR) foams, adhesives, resins, elastomers, binders, and sealants. Isocyanate exposure is irritative to the skin, mucous membranes, eyes, and respiratory tract. The most common adverse health outcome associated with isocyanate exposure is asthma due to sensitization. Objective: The goal of this study is to find statistical predictive model to determine the relationship between airborne hexamethylene diisocyanate (HDI) and selective psychrometric variables. Materials and Methods: All air samplers (by midget impinger) were collected by mini personal sampler pump fixed to work stations near the source of pollution. The air samples and psychrometric parameters were separately collected and determined in a working shift for three periods of 2 h, each at a flow rate of 2 l/min in an impinger containing a solution of reagent of dimethyl sulfoxide in tryptamine [US National Institute of Occupational Safety and Health (NIOSH), 1994]. Results: There was a significant correlation between HDI concentration and relative humidity and dry bulb temperature (P < 0.05). No significant correlation was seen between altitude and dimension of PUR factories (P > 0.05). Conclusions: The finding of the study may be a useful initial tool in estimating possible HDI pollution situation in the PUR workplaces, based on simple psychrometric factors (indoor air temperature and relative humidity).