What are the proper masking procedures?

• A. Stop breathing and close your eyes, don protective mask, clear mask, check the seal of the mask, sound the alarm to alert others, and continue the mission.
• B. Don protective mask, clear mask, check the seal, sound the alarm, and continue the mission.
• C. Stop breathing and close your eyes, then remove the mask and wait for orders.
• D. Put on the mask, seal it, check the seal, and promptly run to safety.

Answer: (A)

The key idea here is to ensure the mask actually protects you before you move on with the mission. Proper masking procedures center on putting the mask on correctly, confirming a good seal, and communicating the hazard to others before proceeding.

First, taking a brief moment to stop breathing and close your eyes helps minimize exposure while you position the mask and start the donning process. Then you put on the protective mask so your face is covered and you’re prepared to breathe through it. After that, you purge or clear the mask so you can breathe clearly and see without fogging or air leaks obstructing you. Next, you check the seal to make sure there are no gaps around the mask; a good seal is essential for the protection to work. Once you’re sealed, you alert others by sounding the alarm so the team knows there’s a hazard and can take appropriate precautions. Only after these steps are complete do you continue with the mission, provided you’ve been given the go-ahead and a safe path forward.

Other options skip or reorder these important elements. For example, omitting the seal check or the alarm means you might not be protected or you might fail to warn teammates, which can put everyone at risk. Removing the mask or rushing to safety without confirming a proper seal can compromise protection and delay necessary safety actions.