Most deadly chemicals have a number of safety requirements that make sure that people understand how to use them correctly. For chemicals that are really dangerous, usually only certain people can buy them and they are used in a setting in which they won’t be breathed in. It’s an important to note that any chemical can be deadly by nature of the fact that humans are not infinitely large. Even too much water can kill someone in spite of the fact that we are mostly water. But certainly some chemicals are very dangerous in very small quantities or can be toxic even if inhaled.

There are a number of government agencies that are responsible for making sure that people don’t come in contact with deadly chemicals unless they are well trained. Though probably the best way to keep people safe is to make sure people know that if they have any question about the safety of a chemical, they should ask someone who knows what they’re doing. Also, the internet can be a great place to find answers on safety also, just be careful to make sure that the website you’re on is valid, such as those ending in .edu or .gov .

Well, that depends on the chemical. Some deadly chemicals we need to work with, and all chemicals are poisonous (even deadly) in too much (people have died from drinking too much water). Education of what is dangerous (and what isn't) is probably the best that I can think of.