Low Risk (CSL-1): Any chemical risk is usually managed by restricting usage of hazardous chemicals. Typically instrument labs and equipment labs do not use hazardous chemicals openly but rather in sealed vials or containers for use inside various analytical instruments.

Moderate Risk (CSL-2): At this level, risk is still usually managed by restricting or limiting the quantities and volume of extremely hazardous chemicals allowed. This level includes laboratories that frequently use biological agents in association with various chemicals.

Substantial Risk (CSL-3): These labs typically work with a wide range of hazardous chemicals that may be, for example, very flammable, highly toxic, carcinogenic, teratogenic, or reactive. CSL-3 labs may use chemical hazard class 3 or 4 materials.

High Risk (CSL-4): The CSL-4 laboratory is a very special purpose laboratory that deals with hazardous chemicals where there is a high risk of potential exposure to highly hazardous chemicals. These laboratories might involve production or isolation of high-hazard chemicals.