A lot of things are allowed, and even FDA approved and yet are not safe. Take for instance ibuprofen (Advil, Motrin, Nuprin, etc.), which killed 2 dozen people during clinical trials from ibuprofen induced hepatitis. Even the FDA estimates well over 16,000 people die each year from the use of nonsteroidal anti-inflammatory drugs (NSAIDs)like ibuprofen. This number is actually way low since many deaths are wrongly attributed to other causes like kidney failure or liver failure rather than the drug. And then there are other side effects of these common drugs, which include tinnitus, loss of vision, aseptic meningitis, etc. These side effects DO NOT require long term use or overdose. They can occur with a single recommended dose. And many of these drugs are readily available over the counter. Unfortunately the FDA is way to cozy with big business and profits therefore come before safety.
Aspartame (Equal, Nutrasweet)is another example. It failed to get approval the first 4 times it came up before the FDA due to the dangerous side effects. The 5th time it was approved, and the FDA official that pushed it through went to work for Monsanto who makes this poison. Aspartame breaks down readily releasing methanol, a powerful neurotoxin. This is what causes the headaches, loss of vision, personality disturbances, etc. The methanol then metabolizes in to formic acid, an irritant, and formaldehyde, one of the strongest carcinogens known. And the FDA does not require other facts to be disclosed either like the fact that Aspartame causes weight gain, which can be a problem for the people most likely to use it.