@LucioMM1 @DeniseTuart @AbraarKaran Your last statement is ridiculous. Touching a respirator does not reduce efficacy to zero. Even somewhat degraded fit factor still has some efficacy. There are studies showing decent filtration even with a short beard.
@LucioMM1@DeniseTuart@AbraarKaran你的最后一句话很荒谬。触摸呼吸器不会将功效降低到零。即使有点退化的拟合因子仍然有一些功效。有研究表明，即使留着短胡子，过滤效果也不错。