This is the six million dollar question.



Most experts would advise that stocking up on gas masks for the whole family is not worth it.



An appropriate gas mask will protect you from breathing in most chemical or biological agents, BUT there are some things to bear in mind before you run out to buy one:

1.)
A gas mask will be effective if you're wearing it before exposure to the agent or immediately upon exposure. If you're inexperienced in the use of gas masks, or if you take to long to find it, you may be putting your life more in danger than if you simply moved quickly to escape the cloud. Of course there's every chance that you will not know what kind of poison is in the air and may not have the appropriate filter in your mask. This may lead to a false sense of security.

In the case of a biological attack masks are of little use. In most cases a biological attack will go undetected for at least several days making the gas mask virtually redundant.

2.)
It's also worth bearing in mind that gas masks are quite expensive. You can expect to spend about $200 for an effective mask. Then you need to decide if (1 you're going to carry the mask with you everywhere you go which would be uncomfortable, impractical and probably not too popular an idea with the kids or (2 you're going to have one mask for home, one for work, one for the car, and so on which would be very expensive.



NOTE:

In the case of a biological attack, breathing through a doubled-up t-shirt will greatly increase your chances of survival in an emergency situation. Unfortunately, this method isn't effective against most chemical agents.