Quantitation of 3,3’-Dichloro-4,4’- Diaminodiphenylmethane (MOCA) in the Work Environment by GC/MS

Introduction

3,3’-dichloro-4,4’-diaminodiphenylmethane (MOCA) is commonly used as a hardener for urethane resin in the manufacturing and construction industries. Under Japan’s Ordinance on Prevention of Hazards due to Specified Chemical Substances, MOCA is a substance under supervision in the Specified Group-2. As such, it is mandatory to monitor the workplace air (TWA: 0.005mg/m3) where MOCA is manufactured or handled. ”Notification of Partial Revision of Working Environment Measurement Standards, Etc.” (Notification No. 18 of Japan’s Ministry of Health, Labor and Welfare) was announced in April 1st 2020. The revisions mandated the use of solid adsorption sampling method and gas chromatograph effective April 1st 2020. In this article, analysis of MOCA in the working environment was conducted according to a new method developed by the Japan Industrial Safety and Health Association (JISHA) (Ishii et al., 2020).

June 25, 2023 GMT