This is great. Green rubberised trousers with natty braces, green rubberised smock, black rubber lace-up overboots, two layers of gloves, and a black rubber respirator with screw-on filter and built-in drinking straw. Price £340 including overnight delivery and packet of chemical detector paper. Not bad.

The only problem is you have to get the respirator on in nine seconds. That's how long you've got from the first sign of nerve gas. Ideally, you should already be wearing all the rest of the kit because a few drops of vapour on your skin could kill you. You should also have started taking NAPS (Nerve Agent Pre-treatment Set) tablets every eight hours.

This is fine if you're in an army. You can walk around all day in an NBC suit and get paid for it. Your army is also likely to have an early-warning system of some kind - sirens, whistles, lights - so you might even get more than nine seconds' notice. And of course, if your army is the one launching the nerve gas attack, you'll probably get even more time to prepare.

The next problem is that the really neat anti-nerve gas stuff is not for sale. When you feel the first symptoms, you're supposed to inject yourself in the thigh with a "Combopen" - a mixture of a muscle relaxant, a substance to stop you drooling, and Atropine, which boosts your immune system. But if you want a Combopen, you'll have to join the army. There's no legal way to buy it.

This is probably just as well, because the Atropine is nearly as dangerous as the nerve gas. "The shock it does to the system may just kill you," a defence equipment supplier told me.

So forget the Atropine. In practice, if you're out in the open and you think there's nerve gas around, get your respirator on and get under cover - inside a car or a building, anything that the nerve gas vapour will take time to penetrate. That will buy you some time to wrestle your way into your NBC suit. Assuming you're carrying it around with you.

Next... What if you're an Iraqi?