Abstract: Employee #1 was applying Polygard #650LTFR primer to the concrete walls of 5 ft by 5 ft planter boxes with varying depths of 8 ft, 12 ft, and 16 ft. Two of each size (6 in all) were to be primed. They were confined spaces. The primer was pure 1,1,1 trichloroethane (TCE). Employee #1 was wearing a cartridge type half face respirator, rather than the supplied air type required for TCE. Employee #1 was overcome and became unconscious from the toxic TCE vapors. Measurements indicated at least 80,000 ppm of TCE vapors at the bottom of the 16 ft planter box that Employee #1 had entered. The IDLH level is 1,000 ppm. Employee #2, without a respirator, attempted to rescue Employee #1 but was overcome and fell unconscious. The fire department rescued both Employees #1 and #2.