1

Contained use of no or negligible risk, for which containment level 1 is appropriate to protect human health and the environment.

2

Contained use of low risk, for which containment level 2 is appropriate to protect human health and the environment.

3

Contained use of moderate risk, for which containment level 3 is appropriate to protect human health and the environment.

4

Contained use of high risk, for which containment level 4 is appropriate to protect human health and the environment.