The purpose of the Level I materials balance for 2,4-Diaminotoluene is to evaluate the sources of release of 2,4-DAT to the environment. 2,4-Diaminotoluene is produced commercially for use in the manufacture of 2,4-toluene diisocyanate and dyes. 2,4-Toluene diisocyanate (2,4-TDI) production is estimated to account for 99% of 2,4-DAT use. 2,4-Toluene diisocyanate is commercially manufactured for use in the production of urethane products, mainly polyurethane foams. 2,4-Diaminotoluene is produced directly through its manufacture and indirectly through the hydrolysis of 2,4-TDI and polyurethane foams, the metabolism of 2,4-dinitrotoluene, and the degradation of dyes. Small quantities of 2,4-DAT are imported into the U.S. directly and as a contaminant in 2,4-DAT-containing dyes. The major sources of release of 2,4-DAT to the environment are 2,4-DAT manufacture and 2,4-TDI hydrolysis. Minor sources of release are TDI production, the use of polyurethane foams, dye production and use, the import of 2,4-DAT and the export of TDI. Releases of 2,4-DAT appear to be greatest in areas of West Virginia and Louisiana. Of the 196,000 kkg of 2,4-DAT estimated to have been produced in 1977, greater than 10,600 kkg (5.4%) is estimated to have been released to the environment during that year.