文档介绍：1 Respiratory protective Devices -- Compressed air for breathing apparatus 呼吸防护装置- 呼吸装置压缩空气 2 National foreword 国家前言 This British Standard is the English language version of EN 12021:1998. 这是英国标准的 EN 12021:1998 英文版本。 Clause of this European Standard requires that, in any event all contaminants shall be kept to as low a level as possible and shall be below the national exposure limit. National Occupational Exposure Limits (OEL) for substances hazardous to health are published yearly by the Health and Safety Executive and can be found in Guidance Note, Occupational exposure limits (EH40). In the context of this European Standard below the national limit will mean that the concentration level should not be greater than 10%of the relevant time (8h) weighted average OEL. 第本欧洲标准规定,在任何情况下污染物都应保持在尽可能低的水平,并应低于国家的暴露极限。国家职业卫生标准有害健康物质是每年出版的健康和安全执行,在指导下可以找到,职业接触限值( EH40 )。在这一背景下欧洲标准低于国家限制将意味着浓度水平应不大于 10 %的相关时间( 8小时)加权平均职业接触极限( OEL )。 The UK participation in its preparation was entrusted by mittee PH/4, Respiratory protection, to mittee PH/4/1, Selection and terminology, which has the responsibility to: 英国参加其筹备委员会已委托 pH/4 、呼吸的保护,以小组委员会 PH 值 1, 4// 选择和工艺,其中有责任: D aid enquirers to understand the text; 援助查询者了解本文;D present to the responsible mittee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; 提交给欧洲委员会负责调查有关的任何解释,或建议的改变,并保持英国利益的情况;D monitor related international and European developments and promulgate 3 them in the UK. 监测有关的国际和欧洲的发展和他们在英国的传播。 A list anizations represented on this mittee can be obtained on request to its secretary. 在这个小组委员会的代表组织的名单,可向其部门获得要求。 Cross-references 交叉引用 The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, orby using the Find facility of the BSI Standards Electronic Catalogue. 英国标准是执行国际或欧洲的刊物本文件中提到可能会发现在该协会所订下的标准目录题为国际标准对应指数,