To perform a user seal check on a 3M valved, cup shaped disposable respirator, place both hands completely over the respirator and inhale.The respirator should collapse slightly.

• 若检查3M的有阀拱形一次性防护口罩，将双手完全盖住口罩，然后吸气，应感觉口罩有稍微的塌陷。