What do asbestos, mercury, and heroin all have in common? Each of these wonderfully dangerous items were at some point widely distributed to the public to be breathed, taken as medicine, and absorbed casually through toys — here’s looking at you, China — with no knowledge of their health-destroying side effects.

The list of household items once thought safe is longer than you might think, and it’s sobering to know the list grows a little longer every year. Here are six of the more common examples:

Shampoos — 2008
Siloxanes are another substance that’s recently come under media fire, more specifically D4 and D5 siloxanes. Siloxanes can be found in a variety of household products, such as deodorants, shampoos, and plastics. Although the chemicals pose no major health risks to people, according to Environment Canada, they are so widely used that concerns have arisen about iats widespread introduction into the environment. Siloxanes remain in an environment for extremely long periods of time and the government will soon introduce restrictions on the amount of the substance permitted in any variety of product.

Water Bottles — 2008
2008 was a big year for Bisphenol-A (BPA), which can be found in water bottles and other plastics. After several reports were released questioning the safety of the chemical, a media panic ensued. BPA was quickly pulled from every shelf and replaced with BPA free plastics. Subsequently, new scientific studies have surfaced stating that the negative effects of BPA were overstated and indecision over the topic remains the one consensus in the scientific community. But hey, now we all have nice shiny aluminum water bottles — everyone wins!

A/C And Hair Spray —1989
Unlike other items on this heavily condensed list, chlorofluorocarbons (CFC) are not present because of their ability to harm people. In fact, CFCs are non-toxic, non-carcinogenic, and basically harmless to people, having been used in spray cans and refrigerants throughout the ’70s and ’80s. The danger of CFCs is their disastrous effect on the environment. Once CFCs are released into the air, they move to the stratosphere, where under the correct temperature, a pound of CFCs can destroy several hundred times its weight in ozone, the simple oxygen-based molecules that protect our planet from the sun’s powerful ultraviolet rays. Scientists are still working hard to calculate how much of global warming we can safely blame on CFCs. Oddly enough, CFCs made Canada’s list of toxic substances in 1989, the same year the death knell sounded for the ’80s hair metal fashion it helped spawn.

Pesticides — 1940s
Dichloro-Diphenyl-Trichloroethane (DDT) suffered a long fought — and doomed — battle with the media. After being invented in 1939, it was hailed as the pesticide that would rid the world of malaria, and for several decades it nearly did just that. But alas, just like in Jurassic Park, life found a way. Mosquito populations became resistant and rebounded, in some places to levels higher than they’d ever been. Eventually, DDT showed itself to be an extremely persistent organic pollutant. It can remain a contaminant in soil for decades after spraying and cause chronic asthma when inhaled. It travels with frightening speed up food chains, accumulating in organisms, and over long periods of time can lead to a variety of cancers.

Paints and Plumbing —
Lead was not only one of the first items added to Canada’s List of Toxic Substances, it’s also a perfect example of the ubiquity a toxic chemical can attain. Accounts of lead use —  as well as lead poisoning — date back as far as the Greeks, and throughout the industrial revolution it was hailed as a miracle metal for the myriad of uses its malleability enabled. It was used in almost every product conceivable: in paints, for plumbing, in children’s lunchpails, and to disinfect the eyes of newborns. Lead is still commonly used in plumbing, batteries, and bullets, although we’re now aware of its highly neurotoxic effects. Symptoms of lead poisoning depend largely on the amount of exposure and can range from subtle changes in blood pressure to reduction of children’s mental abilities, reproductive problems, and kidney damage.