As soon as you’ve smelled the gas’ scent, it means that you’ve been exposed. You’ll need to take immediate action to limit or counter the effects of the gas. Sulfur mustard gas can be odorless or smell like mustard or onions. Chlorine gas often has a pineapple, pepper, or bleach scent. Sulfur mustard gas can appear brown or yellow in the air. However, it can also be clear and invisible to the naked eye, like sarin gas.
Take the path to exit the building that appears to dodge any clouds or concentrations of the gas, if visible.
Staying outdoors will expose you to a higher concentration of the gas. Moving indoors will not provide complete protection from the gas, but it will minimize your exposure until you can get help. If you are outdoors and indoor shelter isn’t available, try to get to higher ground. Most chemical gases will sink to the ground, so being higher up will lessen your exposure.
The goal here is to block off any and all openings that will allow the gas to move from outside to indoors. These actions will help to keep your indoor air as uncontaminated as possible.
If you have duct tape, apply it to the edges of the door and any windows. Although it isn’t always 100% effective, moving to a small, isolated space can improve the quality of air that you’ll breathe during a gas attack.
For example, nerve agents, such as VX, cause damage through skin contact, so only a full weapons-grade hazmat suit will protect you. Make sure that your suit or mask fits you securely. A mask or suit with gaps on the edges can easily let gas slip inside. Some suits or masks also require power sources, typically batteries, or air canisters. You should always store your protective gear with extras of these important components. If you are without a mask or suit, pull up your shirt so that the fabric covers your mouth and nose. The fabric will act as a temporary, makeshift air filter.
A handkerchief or any other fabric can also be used as the base of the mask. Watch out for the tell-tale scent of bleach that often indicates a chlorine attack. This type of mask was used by soldiers in WWI to survive chlorine gas attacks.
If possible, cut your clothes off instead of pulling them up over your head, which can help limit your exposure to the gas.
Realistically, in the event of a gas attack, you can expect to wait some time before receiving any emergency assistance or perhaps even updates. Try to stay in contact with the outside world the best that you can. To avoid running down your radio or phone batteries, check for news at particular intervals, such as every 30 minutes.
Toxic gas exposure often requires continuous monitoring because your symptoms do not always develop rapidly. With chlorine exposure, pulmonary edemas can develop up to a day after initial exposure. Not all gas exposures can be treated the same. Chlorine gas exposure, for example, requires close monitoring of the pulmonary system, including oxygen treatments. It’s advisable to stay indoors for as long as you can post-attack, as it takes some gases days to dissipate. Unless you are critically injured, the best plan initially is to shelter in place and wait for medical help to come to you.
Sarin gas, for example, is treatable with an antidote. However, it must be used within hours of exposure.
