Question # 545

545. A facility processes methylenebis-phenylisocyanate abbreviated MDI. MDI is listed under the EPCRA section 313 diisocyanates category with the CAS number 101-68-8. The MDI purchased by the facility, however, has the CAS number 26447-40-5. How should the facility treat this material with regard to Section 313 reporting requirements?
The EPCRA section 313 listed chemical and the purchased chemical are not necessarily the same chemical. The purchased chemical is termed by the Chemical Abstract Service as an incompletely defined substance that may be or may contain the listed chemical. The facility must use all available information (e.g., supplier notification information), to identify the amount of the listed toxic chemical present in the purchased material for threshold determinations and release and other waste management calculations. If this material does contain MDI, the quantity of MDI present should be included in all threshold calculations for the diisocyanates category.