Different permeation testing laboratories use different testing systems. This can lead to a tremendous difference in reported breakthrough times for the exact same material. To reduce such problems, all permeation tests of chemical protective clothing materials should be conducted to a minimum detectable permeation rate of 0.14 ug/cm²/min. In virtually all cases, as long as this level of system sensitivity is achieved, it makes little difference what testing system is used. It is low enough to detect significant concentrations of chemicals as toxic as chemical warfare G Agent, yet it is achievable by today's laboratories within the current state of the art in permeation testing. Where situations demand an exception to this proposed rule, the tester should report the actual detectable permeation rate achieved so that the user may note the exception to the rule.