Polyurethanes are produced by reacting diisocyanates with polyols. Other non-reactive additives, such as catalysts, surfactants, blowing agents or flame retardants, may be included in the process. Atmospheric emissions of the diisocyanates (MDI and TDI) during isocyanate production are low, as they are typically carried out in closed systems with ventilation controls in place.
Environmental Airborne Emissions Reporting and Testing
Under the Toxics Release Inventory (TRI) program, facilities that manufacture, process or otherwise use TDI, MDI or PMDI and exceed the usage threshold limits set by the U.S. Environmental Protection Agency (EPA), are required by EPA to submit a Form A or Form R by July 1st of each year to EPA and the appropriate state agency. To aid those facilities required to submit TRI forms, ACC’s Center of the Polyurethanes Industry (CPI) offers a Regulatory Compliance Assistance Program (RCAP). Intended to provide some assistance to RCAP users, this program has a number of built-in formulas to estimate emissions from typical process applications and activities. For assistance or questions regarding TDI, MDI, PMDI or TRI reporting, contact CPI RCAP Software User Support.
EPA Testing Methods – Emissions and Stack Emissions
EPA has published various test methods relating to environmental monitoring and stack testing. The following methods for MDI and TDI are included on EPA's Emissions Measurement Center Test Methods web page.
- Method 207 (now known as OTM 14) - A Method for Measuring Isocyanates in Stationary Source Emissions Formerly known as Air Method 0207, this method is now referred to as Air Method OTM 14. It is applicable to the collection and analysis of isocyanate compounds from the emissions associated with manufacturing processes.
The following two methods are listed by the EPA as conditional methods: