LC99 of DHMO is 10^6 ppm

The USAF invests more effort in training its personnel for hazardous materials awareness than for first aid. You'll learn plenty about how much water it takes to drown a person (hence the title of this post, which translates to 'the concentration of water in air that is lethal to inhale for 99 percent of typical people is one million parts per million') but you will not learn how to resuscitate that limp, cold buddy of yours, whom you pulled out of floodwater. Instead of a full-blown American Red Cross First Aid certification for all members, airmen receive "Self-Aid and Buddy Care" slideware, lecture, and demonstration. Not First Aid, but Self-Aid. Harrumpf.

Even in my career field, I'm more likely to catch a bullet or break my leg, or have to patch up somebody else's bullet hole or compound fracture, than to cordon off a spilled tanker truck of organic peroxide, n.o.s. Don't get me started on such military essentials as basic marksmanship either---Swen Swenson has covered that, with my two cents thrown in, of course.