This testimony before the Subcommittee on Oversight of the House Committee on Science and Technology answered several concerns connected with the exposure of workers to radiofrequency radiation from heaters and sealers. Such heaters and sealers have been used in the manufacture of many plastic products, wood lamination and veneer processes, including glue setting; embossing and drying operations in the textile, paper, plastic, and leather industries; and curing of various materials including plasticized polyvinyl-chloride, wood resins, polyurethane foam, concrete binder materials, rubber tires, and epoxy resins. At least 100,000 workers have been exposed, probably more. Most have been women of child bearing age. Measurements have been obtained as high as 2500 volts/meter for the electric field and 13 amperes/meter for the magnetic field. Excessive levels can be reduced by proper shielding. The current OSHA standard sets a limit for occupational exposures to a maximum power density of 10 milliwatts/centimeter squared.