Methods were sought to reduce exposure to dimethylethylamine (598561) (DMEA) among foundry owners, operators, and workers and manufacturers of polyamides, due to possible vision disturbances and acute physical distress which may result. An investigation was made at an aluminum casting foundry where blurring, fogging, and halo visual disturbances had been reported among workers exposed to DMEA, along with headaches, nausea, stomach pain, and increased heart rate. Medical and environmental studies were made. Exposure concentrations causing effects were measured at equal to or greater than 6mg/m3, or 2 parts per million (ppm), 8 hour time weighted average. Exposures as high as 29mg/m3 (9.7ppm) for 15 minutes also may have caused adverse effects. There was no current permissible exposure limit for DMEA. Leakage around pressure tight seals in corebox machine gaskets may have accounted for some excessive exposure. It was recommended that more frequent maintenance of these gaskets be undertaken along with other engineering controls. Work practices should be adjusted so as to reduce the pressure that delivers DMEA to coreboxes and to avoid excess gaseous DMEA in the corebox machine. Protective gloves should be worn. Evacuation plans should be developed in the event of a spill, leak, or other serious accident that may cause high concentrations of DMEA in the workplace.