BS 8468-6.2 pdf free download

BS 8468-6.2-2020 pdf free download.Respiratory protective devices for use against chemical, biological, radiological and nuclear (CBRN) agents Part 6.2: Constant flow compressed air line equipment – Specification.
3 Terms and definitions
For the purposes of this part of BS 8468. the terms and definitions given in BS EN ISO 16972, BS EN 134, BS EN 14594 and the following apply.
3.1 chemical agent
toxic chemical that can be disseminated to cause harm
NOTE Chemical agents include chemical warfare agents and toxic industrial chemicals.
3.2 biological agent
microorganism that is a pathogen and that has the potential to be used intentionally to cause harm NOTE Human pathogens are relevant to RPD selection,
3,3 radiological agent
substance that emits ionizing radiation and that could be disseminated to cause harm
3.4 nuclear agent
radioactive matter resulting from a nuclear explosion or accidental release from a nuclear facility
3.5 decontamination
physical and/or chemical process of removing as much contamination as possible from people or equipment
4 Requirements
4.1 General
NOTE Compressed air line breathing apparatus with constantflow may be used with afuilface mask, hood, helmet or suit (the apparatus).
The apparatus shall be constant floW equipment meeting type CBRN1 or type CBRN3 in accordance with BS 8468-8.
If the facepiece is a full face mask, it shall conform to BS EN 136: 1998, class 2 or class 3.
Type CI3RN1 devices shall conform to BS EN 14594:2018, class 4A or class 4B; or shall conform to BS EN 1073-1:2016+A1, class 1-5.
Type CBRN3 devices shall either conform to BS EN 14594:2018, class 4A or class 4B, and the lower inward leakage specified in £4; or shall conform to BS EN 1073-1:2016+A1, class 3, 4 or 5.
The apparatus shall also conform to the chemical agent permeation and penetration resistance specified in 4.5. according to CBRN type.
4.2 Preconditioning
Type CBRN1 samples shall be preconditioned in accordance with BS EN 14594 or BS EN 1073-1 prior to visual inspection (see 411) and testing for chemical agent permeation and penetration (see 4A and 415, respectively) where required.
Type C13RN3 samples shall be preconditioned in accordance with BS EN 137 prior to visual inspection
(see 4.3) and testing for inward leakage and chemical agent permeation and penetration (see 44 and 4L5J respectively) where required.
4.3 Visual inspection
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 in accordance 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 in accordance with BS EN 13274-1:200 1, 8.4c) with 10 test subjects.
NOTE This requirement for CBRN3 is more stringent than the one given in BS EN 14594. Detection systems should take account of the increased sensitivity required.
A minimum of two devices shall be tested, at least one in the as-received state and one preconditioned 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 complete system in accordance with the requirements for type CBRN1 or type CBRN3 devices. Type CBRN3 devices 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 of the liquid test chemicals listed in BS 8467:2006, Annex D. The highest cumulative permeation for the exposed materials of the apparatus, including the compressed-air supply tube (CAST), for each chemical over 4 h shall not exceed 1.25 ig/cm2.
A liquid concentration density for each chemical of 10 g/m2 shall be applied as nominal 1 L drops uniformly over the sample surface. Where a seam closure or fixture is included, at least three drops shall be applied at each critical juncture, such as the seam edge. The test cell shall be assembled in the open configuration.
NOTE Where components are made of materials identical (in corn position and minimum thickness) to those used previously and have been shown to meet these requirements as part of other devices that conform to this British Standard then this information may be used to demonstrate conformity in this instance.
5 Marking
Marking shall be in accordance with the relevant clauses of BS EN 14594.
in addition, each apparatus conforming to this British Standard shall be permanently marked with the standard identifier and year, i.e. BS 8468-6.2:2020’s, and type CBRN1 or type CBRN3, as appropriate.
Any CBRN RPD component forming part of the breathable gas supply chain that can be removed without the use of tools shall be marked with the letter combination “CBRN’ in a sans-serif font.
NOTE Marking can be on a label or embossed on an externally visible area of the component.BS 8468-6.2 pdf download.