For the purposes of this chapter, a hazardous chemical agent is :
1° Any chemical agent mentioned in Article R. 4411-6;
2° Any chemical agent which, although not meeting the criteria for classification, as such or in a mixture, may present a risk to the health and safety of workers due to its physico-chemical, chemical or toxicological properties and the ways in which it is present in the workplace or used, including any chemical agent for which decrees set an occupational exposure limit value.