English 
Spanish 
Chinese 
Russian 
German 
French 
Portuguese 
Hindi 当社グループは 3,000 以上の世界的なカンファレンスシリーズ 米国、ヨーロッパ、世界中で毎年イベントが開催されます。 1,000 のより科学的な学会からの支援を受けたアジア および 700 以上の オープン アクセスを発行ジャーナルには 50,000 人以上の著名人が掲載されており、科学者が編集委員として名高い
。オープンアクセスジャーナルはより多くの読者と引用を獲得
700 ジャーナル と 15,000,000 人の読者 各ジャーナルは 25,000 人以上の読者を獲得
抽象的な
Respirator User with Breathing Air from Independent Sources of the Ambient Atmosphere
Yuan S
The Maximum Use Concentrations for respirators is calculated by multiplying the Assigned Protection Factors for the respirator by the permissible exposure limit. The Maximum Use Concentrations is the upper limit at which the class of respirator is expected to provide protection. Whenever the exposures approach the Maximum Use Concentrations, then the employer should select the next higher class of respirators for the employees. Employers must not apply Maximum Use Concentrations to conditions that are immediately dangerous to life or health, instead, they must
use respirators listed for immediately dangerous to life or health conditions of this standard. When the calculated Maximum Use Concentrations exceeds the immediately dangerous to life or health level for hazardous substances or the performance limits of the cartridge or canister, then employers must set the maximum Use Concentrations at that lower limit