BS 8468-6.2:2020 pdf download – Respiratory protective devices for use against chemical, biological, radiological and nuclear (CBRN) agents Part 6.2: Constant flow compressed air line equipment — Specification
toxic chemical that can be disseminated to cause harm
NOTE Chemical agents include chemical warfare agents and toxic industrial chemicals.
microorganism that is a pathogen and that has the potential to be used intentionally to cause harmNOTEHuman pathogens are relevant to RPD selection.
substance that emits ionizing radiation and that could be disseminated to cause harm
radioactive matter resulting from a nuclear explosion or accidental release from a nuclear facility
physical and/or chemical process of removing as much contamination as possible from peopleor equipment
NOTE Compressed air line breathing apparatus with constant flow may be used with a full face mask, hood,helmet or suit (the apparatus).
The apparatus shall be constant flow equipment meeting type CBRN1 or type CBRN3 in accordancewith BS 8468-8.
lf the facepiece is a full face mask, it shall conform to BS EN 136:1998,class 2 or class 3.
Type CBRN1 devices shall conform to BS EN 14594:2018, class 4A or class 4B; or shall conform toBSEN 1073-1:2016+A1, class 1-5.
Type CBRN3 devices shall either conform to BSEN 14594:2018,class 4A or class 4B, and the lowerinward leakage specified in 4.4; or shall conform to BSEN 1073-1:2016+A1, class 3,4 or 5.
The apparatus shall also conform to the chemical agent permeation and penetration resistancespecified in 4.5, according to CBRN type.
Type CBRN1 samples shall be preconditioned in accordance with BS EN 14594 or BSEN 1073-1 priorto visual inspection (see 4.3) and testing for chemical agent permeation and penetration (see 4.4 and4.5, respectively ) where required.
Type CBRN3 samples shall be preconditioned in accordance with BSEN 137 prior to visual inspection(see 4.3) and testing for inward leakage and chemical agent permeation and penetration (see 4.4 and4.5, respectively ) where required.
Where visual inspection is required, it shall be in accordance with BS 8468-8:2020,Clause 6.A minimum of two samples shall be inspected.
4.4 Inward leakage
CBRN1 devices shall have an inward leakage of <0.1% when tested as a complete system inaccordance with BS EN 13274-1:2001,8.4c) with 10 test subjects.
CBRN3 devices shall have an inward leakage of <0.01% when tested as a complete system inaccordance with BS EN 13274-1:2001,8.4c) with 10 test subjects.
NOTE This requirement for CBRN3 is more stringent than the one given in BSEN 14594.Detection systemsshould take account of the increased sensitivity required.
A minimum of two devices shall be tested, at least one in the as-received state and onepreconditioned in accordance with 4.2.
4.5 Chemical agent permeation and penetration
Where the apparatus can be tested in accordance with BS 8468-8, it shall be tested as a completesystem in accordance with the requirements for type CBRN1 or type CBRN3 devices.Type CBRN3devices shall use the HD droplet patterns given in Figure 1 to Figure 5 of this British Standard.
Where the apparatus cannot be tested in accordance with BS 8468-8, it shall be tested against all ofthe liquid test chemicals listed in BS 8467:2006,Annex D.The highest cumulative permeation forthe exposed materials of the apparatus, including the compressed-air supply tube (CAST), for eachchemical over 4 h shall not exceed 1.25 ug/cm2.
A liquid concentration density for each chemical of 10 g/m3 shall be applied as nominal 1 uL dropsuniformly over the sample surface.Where a seam closure or fixture is included, at least three dropsshall be applied at each critical juncture, such as the seam edge.The test cell shall be assembled in theopen configuration.
NOTE Where components are made of materials identical (in composition and minimum thickness) to those usedpreviously and have been shown to meet these requirements as part of other devices that conform to this BritishStandard then this information may be used to demonstrate conformity in this instance.BS 8468-6.2 pdf download.