Are substances in nanoforms more dangerous than they are in their normal size? Some are and some are not. Just like any other chemical substance, nanomaterials have to be assessed separately.
Nanomaterials and their effects on our bodies can be just as different as any other chemical. Nanomaterials therefore need to be assessed separately as any other substances. If a substance is assessed to be harmless in its bulk form, it still has to be looked at in the nanoform.
How to find out if a nanomaterial is toxic
One of the things that scientists try to find out is whether nanomaterials enter and stay in our bodies and build up over time, or if they are excreted or digested. This is not an easy task.
There are many things to consider when trying to find out if a nanomaterial is harmful or not, such as size and shape and not least how they behave once the particle is broken down to the nano size. For example, some nanomaterials might be able to reach body parts that other particles can’t and you need to find out what implications that might have.
Being extremely small as they are of course only makes this more difficult. Instruments that are able to detect and analyse nanoparticles have only recently been developed.
What are the risks?
Some nanomaterials are able to damage cells in the body while others have shown to be harmless. Because of their small size, some of them are able to reach deep into the lungs when inhaled. Once there, they might be able to cause inflammation. Another risk is that some nanomaterials might travel through the blood and enter organs like the liver, kidney, heart or spleen where they might cause diseases.
Studies using rats have shown that some nanoparticles are more likely to cause inflammation and cancer than the same substance in a larger size.
Nanoparticles can enter the human body in three different ways:
- You can inhale them
- You can eat or drink them
- Or they can enter your body through the skin
Are we exposed?
When assessing the risk of nanomaterials, you also need to find out whether we are exposed to them. Nanomaterials are found in many places including nature. They occur, for example, in volcanic eruption ash, in dust and in sea breeze, but also in urban environments from diesel exhaust fumes, for instance.
We still need more information about many nanomaterials used both in workplaces and in consumer products to be able to assess their safety.
ECHA and other authorities are working to clarify how chemical legislation is applied for nanomaterials, and by that better ensure their safe use.