If you’re seriously asking about dangerous stuff with no controls, **jnglmassiv ** has it right. Seriously, you can buy truckloads of ammonium nitrate all over the Midwest with no questions asked. Park a truckload of that crap (mixed with diesel fuel, of course) on a busy city street and set it off in rush hour – hundreds killed in a flash.
For pure evil satire, though, I like **Sunspace’s ** answer.
How about a condom? You have noticed that those things don’t come with any kind of guarantee.
Cigarettes and automobiles would probably be tied for #2 there. Automobiles for obvious reasons, but if you look through the Darwin awards, you’ll be amazed how often the phrase “and then he decided to have a smoke” comes up, just before phrases like “huge explosion,” “massive fireball” or “ignited his bandages.”
These days it’s spinach
I’d have to go with natural gas. The suppliers have the restriction that they have to make it stink, but I don’t have any.
Also, depends on how we define “without restriction”.
To purchase gasoline, you need to have an approved container.
To purchase cigarettes, you need to be 18.
Heidi Fleiss.
Alcohol, tobacco, and firearms. It’s not just a government department, it’s a party.
I’d say black powder. Pretty much the only explosive for something like 900 years, and you can go into your local Bass Pro Shops (among many other sporting goods stores) and buy it in 1 lb cans for about twenty dollars.
You don’t have to sign anything, show any id, etc… (although I imagine the salesmen might balk at letting a 13 year old buy it).
Food: misused, it introduces Americans to more health risks than any other substance.
Since when? Oh, sure, that may be the law. But if I go up and stick my credit card into the pump, I bet it doesn’t check.
Tobacco is a silly answer. It’s so barely hazardous that many people smoke it daily for decades before a problem results. Household bleach is far more hazardous.
Yah, but you can only buy it in it’s watered down form in The US although it can be distilled to a purer state.
I’m thinking a trampoline is a pretty dangerous item considering we buy them for kids.
Wow, I was going to say it depends entirely on how you use it, and discuss crashing a plane into the Superbowl stadium or dumping rat poison into the local water supply, but after reading this reply, I changed my mind.
Everybody’s got funny answers. I have only a “maybe could be” scary scenario I picked up from a (it seemed to me) well-researched suspense novel.
The powder that automobile airbags are packed in is extremely toxic. It binds to the hemoglobin in your blood stream and basically suffocates you. It can do this if it’s inhaled or ingested. Now, under normal circumstances, the airbag deploys and this powder is oxidized into something completely harmless. But go to a junk yard or pick-a-part place and take out the piece that holds the airbag, and if you know how to open it without deploying, and if you’re wearing protective gear…
The downside of mentioning this is, of course, that I can now never use it to rid the world of some evil doer. Or, you know, someone who really annoys me.
Right now, I can go to the dollar store, buy a gallon of bleach and a gallon of ammonia.
I can mix them up, and then dump them into the airsystem of a large building.
I won’t, because I’m not that kind of guy (anymore) but the fact is there.
Please don’t ask for a cite, but I seem to recall an attempt to regulate sales of knives somewhere. Seems like it was around here in the midwest. My family had a WTF type moment reading about it.
Airbags are usually packed in cornstarch; the toxic chemical you’re thinking of is the propellant sodium azide:
Yeah, here is a great idea, we are going to design a safety system that will allow the driver and passenger to survive an accident that would otherwise kill them, but just to let them know karma is a bitch we will use a poisonus, corrosive power that will kill them slowly. :rolleyes: :rolleyes: :eek: 
The power that the bag is packed with is either corn starch or talcum power to allow the bag to slide out with less friction. :rolleyes:
The propellent could be one of many things. Sodium Azide is one. Yes it is toxic, but it is not a powder when used in the airbag, it is a solid block. After ignition you are left with N[sub]2[/sub].
Don’t feel bad, Read the first post here for the tinfoil take on the subject, and then scroll down to the third post for the rational take on the subject.
Dunno about battery acid (or what acid specifically they’re using in batteries now, or what kind of batteries you mean) but I once bought a gallon of 11 molar hydrochloric acid without being asked to show ID, and I was 17 at the time. So I’ll definately second Tristan about the nasty chemicals you can buy in grocery stores and hardware stores.
I’ve never bought any, but the replacement mantles for propane lanterns contain thorium, which is radioactive. It’s in low quantities, but that hasn’t stopped some people from refining it in their backyards.
If we’re taking the OP literally, then alcohol and tobacco aren’t options, because there are restrictions on their purchase; you need to be 18 or 21 (in the U.S., anyway).
For a couple of bucks, from the grocery store, if you mix ammonia and chlorine bleach… Well, it’s very, very bad.