BS 8468-8:2020 pdf free.Respiratory protective devices for use against chemical, biological, radiological and nuclear (CBRN) agents.Test methods.
BS 8468-8 NOTE1 The test equipment allows a complete RPD to be challenged with chemical agent and the permeation of agent into the inhaled air to be measured for an extended period.
Other test set-ups that are identical in principle but vary in detail to that described in this standard may be used, so long as the conditions given in Table 1 are maintained. Details of the test set-up may vary according to the RPD type.Three RPD shall be tested in an atmosphere containing GB vapour and three RPD shall be tested in an atmosphere containing HD vapour In each set of three, two RPD shall be pre-conditioned as specified in accordance with the relevant part of BS 8468 and one tested “as received”.NOTE2 All components and accessories which form part of the breathing circuit are tested.The test requirements for each CBRN type shall be in accordance with Table 1.Pass/Fail criteria The maximum levels of permeation in Table 1 shall not be exceeded.Either of the following criteria shall constitute a failure: a] three consecutive sequential instantaneous concentration data points (mg/m3) during execution of the test at or exceeding the value in Table 1; or b) exceeding the maximum breakthrough dosage (concentration integrated over test duration) (mg- min/m3) as shown in Table 1, calculated after completion of the test.Distilled sulfur mustard (HD), liquid purity≥95% traceable to a nationally or internationally recognized standard, used within one year of analysis.Sarin (GB), liquid purity >95% traceable to a nationally or internationally recognized standard, used within one year of analysis.Dilute HD, used to test the calibration of the continuous air monitoring system, at a concentration chosen to be at the mid-point of the continuous air monitoring system calibration curve.Dilute GB, used to test the calibration of the continuous air monitoring system, at a concentration chosen to be at the mid-point of the continuous air monitoring system calibration curve.Breathing gas, in accordance with the water content requirements of PD ISO/TS 16975-1:2016, Table 12. Oil, particle and condensate content shall be <0.5 mg/m3.BS 8468-8 pdf download.