Respiratory symptoms associated with the use of azodicarbonamide foaming agent in a plastics injection molding facility

Abstract

Respiratory health variables were studied cross-sectionally in 227 employees of a plastics molding facility where numerous complaints had been apparently associated with the use of azodicarbonamide foaming agent in injection molding. Pre- and postshift respiratory status measures and azodicarbonamide concentrations were also obtained for 17 employees. Cross-sectional pulmonary function differences by injection molding status were not observed. Modest decrements in pulmonary function measures were observed between start and end of shift but with no dose-effect relationship. A strong association was observed for injection molding workers for eye/nose/throat irritation, cough, and wheezing. Additionally, wheezing, chest tightness, and symptoms of chronic bronchitis were strongly associated with work in injection molding during periods in which azodicarbonamide was in use. These results suggest respiratory symptom causation by some combination of azodicarbonamide itself, reaction products of azodicarbonamide formed during injection molding, or other unidentified agents uniquely associated with the process of injection molding with azodicarbonamide foaming agent.

Synthetic Polymers: Polyesters, Polyethers, Polysulfones, and Other Polymers

“…In a plastic products facility, respiratory symptoms in 227 employees were evaluated using a cross-sectional design (210). A strong association was observed for workers in the injection molding department, which used polyphenylene oxide resin with the foaming agent azodicarbonamide (i.e., 1,1 0 -azobisformamide), with eye, nose, and throat irritation, cough, and wheezing as compared with other departments.…”

Azodicarbonamide [MAK Value Documentation, 2017]

“…There are four studies available (Ferris et al 1977; NIOSH 1985 a, b;Slovak 1981;Whitehead et al 1987) that linked symptoms among workers exposed to azodicarbonamide to person-related or workplace-related exposure. The studies included no or only very incomplete information about the concentration of possible decomposition products or other substances used at the plants.…”

“…Spirometric examinations did not yield a decrease in the FEV 1 or FVC values of more than 2% for the 3 workers who subjectively reported severer symptoms at the workplace. The authors also suggested that there may be a healthy-worker effect, and the use of azodicarbonamide had been drastically reduced about 4 or 5 months before the workplace-related lung function tests (NIOSH 1985 a;Whitehead et al 1987).…”

“…The detailed measurements of the exposure to azodicarbonamide in the publication of NIOSH (1985 b) are from employees who used personal breathing masks and are therefore unsuitable for deriving a MAK value. Exposure data from employees who did not use breathing masks can be found only in the investigations of NIOSH (1985 a) and Whitehead et al (1987). In 17 injection-moulding workers investigated, lung function values for FEV 1 and FVC were determined before and after the shift parallel to the exposure measurements, and the results were assigned to 3 exposure groups (0-20, 21-40 and > 40 µg/m 3 ).…”

“…The detailed measurements of the exposure to azodicarbonamide that were reported by NIOSH (1985 b) were derived from workers who used personal breathing masks and are therefore unsuitable for deriving a MAK value. Taking the objectified measurements of the lung function values into account,the average exposure of the three groups of 36 µg/m 3 (0.036 mg/m 3 ) reported by Whitehead et al (1987) is considered to be the NOAEC. However, regarding the work-related symptoms, that were subjectively reported by the workers, a NOAEC cannot be derived .…”