Study on occupational exposure limit of dimethoxymethane in workplace air

Objective To study the occupational exposure limit of dimethoxymethane (DMM) in workplace air.Methods Literature research was conducted on DMM; information on its physicochemical properties,toxicology,and occupational epidemiology was collected.Upon analyzing these data,an occupational exposure limit of DMM in workplace air was proposed according to the guidelines and principles of developing occupational exposure limits for harmful factors in workplaces.Results A total of 165 air samples were collected from DMM manufacturers,14 of which had a DMM concentration over 3000 mg/m3,accounting for 8.48％ of all samples.Compared with the control group,the exposed employees had a significantly increased incidence of discomfort symptoms when exposed to more than 6000 mg/m3 DMN (P＜0.01).No significant differences in the constituent ratios of abnormal results in physical examinations were found between the exposure groups and control group (P＞0.05).Conclusion We recommend to set the permissible concentration-time weighed average to 3100 mg/m3 as the occupational exposure limit of DMM in workplace air in China.This occupational exposure limit standard meets the relevant requirements of toxicology and occupational epidemiology,as well as fits well with our country' s current economical and technological levels.This standard has high applicability in China's domestic settings. Key words: Dimethoxymethane;  Occupational exposure limit