BS 8478:2006 pdf free.Respiratory protectivedevices – Breathing gases fordiving and hyperbaric applications.
BS 8478 The following referenced documents are indispensable for the
application of this document. For dated references, only the editioncited applies. For undated references, the latest edition of the
referenced document ( including any amendments) applies.BS ISO 6145,Gas analysis – Preparation of calibration gasmiotures using dynamic volumetric methods
HEALTH AND SAFETY EXECUTIVE. Workplace exposure limits.Guidance Note EH 40.Sudbury: HSE Books.
For the purposes of this British Standard, the following terms anddefinitions apply.oxygen and nitrogen gas mixture(known as nitrox) gas comprising a specified mixture of oxygen and nitrogen, capable ofsupporting human life under appropriate diving or hyperbaric conditions.
NOTE 1This includes manufactured gas mixtures made up fromcombinations of pure oxcygen and pure nitrogen, with or withoutcompressed air.
NOTE 2 This definition diffevs from that in BS EN 13949:2003 in that itcovers all ooygen and nitrogen gas miatures irrespective of oxygencontent.
The gas shall be tested in accordance with 5.5. If in the test any constituents of the gas are identified that are not listed in Tables 1 to 4,these constituents shall be checked against the list of substances for which workplace exposure limits are given in HSE Guidance.
Note EH 40.No constituent listed in EH 40 shall be present at a levelin excess of one tenth of the eight hour workplace exposure limitgiven in EH 40.
Freedom from particulate contamination When tested in accordance with one of the methods given in 5.12, thelevel of particulates in the gas sample shall not exceed that specifiedin a) or b) as applicable.
Three assessors shall assess each gas mixture. The assessors shall benon-smokers and shall be free from symptoms of upper respiratory tractinfection. The assessors shall be instructed to avoid environments containing tobacco smoke and to avoid using perfumed products,including perfumed soap, deodorant or aftershave, for the 12 h preceding the assessment. They shall also be instructed to wear clothingthat is free from odours such as perfumed detergents or fabric softenersand tobacco smoke.
The assessors shall wash their hands in unperfumed soap immediatelybefore the assessment, and shall wear eye protection and ear protectionduring the assessment. The assessors shall have a break of not less than30 min in fresh air, away from the laboratory, between assessments ofdifferent gas mixtures.BS 8478 pdf download.