The environment is toxic. Sometimes the chemicals in our environment are more toxic than we think or are lead to believe. Many products are banned in European countries, but not in the United States.
Some of the chemicals banned in Europe, but legal in the USA, include formaldehyde, lead acetate, petroleum products, and hydroquinine. The potential harmful effects of these and many more are usually in relation to cancer. These chemicals are or can be carcinogenic.
If you are going to make a change to natural products, there will be lots of research that you need to do on your end.