Polyurethanes are produced by reacting diisocyanates with polyols. Other chemicals, such as catalysts, surfactants or flame retardants, may be included in the process. Atmospheric emissions of the diisocyanates MDI during isocyanate production and most other applications carried out in closed equipment with controls on all vents are usually low.

Large quantities of MDI are routinely transported in a variety of dedicated containers ranging from ships' tanks to plastic drums. In the unlikely event of a spill to the aquatic or soil environments, the MDI reacts to form inert polyureas. Also, MDI react with water to form predominantly insoluble inert solid polyureas and release carbon dioxide. Of course, a spill should be addressed appropriately in compliance with U.S. environmental laws and in accordance with the manufacturer’s SDS.

MDI present on soil as the result of a spill reacts with moisture in the environment and slowly form solid, essentially unreactive polyureas.

Facilities that manufacture, process or otherwise use MDI and exceed the threshold limits on atmospheric emissions 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 reporting year to the EPA and the designated state agency. To provide general guidance during the reporting process, CPI offers a Regulatory Compliance Assistance Program (RCAP). RCAP also offers individual assistance to RCAP users. Each facility must independently determine its reporting obligations. For assistance or questions regarding MDI, PMDI or TRI reporting, contact CPI RCAP Software User Support.

MDI Emissions Estimator*

The free MDI Emissions Estimator provides a fast and convenient method to estimate MDI or PMDI emissions from typical process applications and activities. The tool is available in a lockable spreadsheet allowing users to easily import data and print helpful reports.

* Users' computers must be compatible with Microsoft Excel in order to effectively use the MDI Emissions Estimator.

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