How to determine that I work safely with nanomaterials?

You need to carry out a risk assessment to determine if you are working safely with nanomaterials. A risk assessment considers the toxicity of a nanomaterial in relation to exposure. You can a conduct quantitative (preferable) or a qualitative risk analysis, depending on the exposure and toxicity data available. The possibilities are shown in the scheme below. The uppermost route provides you with the most secure result; the farther you progress in the scheme, the less certain you are that you work safely. A qualitative risk assessment only gives an indication regarding toxicity. More information on how to carry out a risk assessment is given in the Frequently Asked Questions.
 
If the quantitative risk assessment determines that your exposure exceeds the health limit or reference values  then you will need to decrease the exposure by taking control measures. The same applies if the qualitative risk assessment puts your nanomaterial in the ‘high’ or ‘middle’ hazard class. You can assume that you work safely, according to current knowledge, if the exposure is lower than the health limit value. However, please keep in mind that uncertainty increases in the lower region of the scheme.