Respirator efficiency, fit of the respirator, and wear time all play a role in effectively reducing exposures but they cannot eliminate the risk of contracting infection, illness, or disease.

• 呼吸器的过滤效率、适合性和佩戴时间都是有效降低暴露的重要因素，但这些都不能消除使用者受传染和生病的风险。