These chemicals (known as volatile organic compounds) can occur in gaseous form, which means we can inhale them. But there’s a sub-group of volatile organic compounds, called semi-volatile organic compounds. These can occur both in gas form and absorbed on solid surfaces (including all indoor surfaces, as well as dust).

The harm a chemical causes differs depending on how it enters the body.

Ingested chemicals pass through the intestines and liver before entering the blood.

Inhaled chemicals first pass through the lungs where they may be absorbed directly into the blood.

Chemicals that penetrate the skin can also directly enter the bloodstream.

You don’t even need to have an open wound, as the chemicals can be absorbed directly through the skin.