Group leader, Lawrence Livermore National Laboratory, Livermore, CA
Senior engineer, Texas Research International, Austin, TX
Pages: 10 Published: Jan 1988
The Lawrence Livermore National Laboratory's (LLNL) Hazards Control Department has recognized for some time that totally encapsulating chemical protective (TECP) suits must be tested to assure that they function properly with a high degree of reliability. Two general types of tests are necessary to properly evaluate a TECP suit: design qualification tests and field use tests. To develop these tests for the evaluation of TECP suit performance, LLNL is participating in a jointly funded project with the U.S. Coast Guard, the U.S. Occupational Safety and Health Administration, and the U.S. Fire Administration. Four tests have been developed to measure TECP suit performance: a quantitative test, a worst-case chemical exposure test, a pressure leakage test, and a chemical leak rate test.
A quantitative TECP suit test method using Freon 12 gas and an aerosol, polyethylene glycol molecular weight 400 (PEG 400), to measure the leakage of both test agents into the suit is being developed. This leak rate is expressed as a “protection factor” that is calculated by dividing the outside test agent concentration by the suit interior test agent concentration. A worst-case chemical exposure test has been demonstrated using the U.S. Coast Guard's Teflon-coated Nomex TECP suit in a hydrogen fluoride gas cloud.
Two types of field use tests have also been developed. The TECP pressure test measures the suit leak rate by inflating the suit to a prescribed pressure and monitoring pressure drop in the suit over time, ASTM Standard Practice for Pressure Testing of Gas Tight Totally Encapsulating Chemical Protective Suits (F 1052-87). The proposed chemical leak rate test consists of generating a known ammonia concentration in a test room, wearing the TECP suit into the room, and doing a series of prescribed light exercises. The interior of the suit is monitored for ammonia after the test subject exists the test room, and the protection factor is calculated in the same manner as described earlier in the Freon 12 test procedure.
By employing the four TECP suit tests in the various stages of suit development and field use, a high degree of safety can be assured.
totally encapsulating chemical protective suit, protection factor, design qualification tests, field use tests, quantitative test, worst-case chemical exposure test, pressure leak rate test, chemical leak rate test, protective clothing
Paper ID: STP26319S