For the following National Institute for Occupational Safety and Health (NIOSH) filter designations N stands for Not Resistant to oil;R stands for Resistant to oil;and P stands for oil Proof.

　
英 美
  • 答：對經(jīng)過(guò)NIOSH認證防顆粒物呼吸器過(guò)濾元件，N指不適合油性的顆粒物，R指可以抵抗油性的顆粒物，P指能夠防油性顆粒物。
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