Final answer:
A small UAS is not allowed to carry hazardous materials as this would violate the USDOT and EPA regulations aimed at protecting public safety and the environment.
Step-by-step explanation:
No, a small Unmanned Aircraft System (UAS) is not allowed to carry hazardous materials. This is consistent with both the United States Department of Transportation (USDOT) hazardous materials regulations and the Environmental Protection Agency's (EPA) hazardous waste regulations. The transport of hazardous materials is highly regulated due to the potential risks to safety, health, and the environment.
The USDOT has a set of rules known as the Hazardous Materials Regulations (HMR) which detail the proper identification, classification, packing, marking, labelling, handling, and transport of hazardous materials. The EPA has regulations dealing with the management of hazardous waste. These rules have been established to ensure the public's safety and to mitigate the risks posed by the transport and disposal of hazardous materials.
As such, operators of small UAS must comply with these regulations, and transporting hazardous materials using these aircraft would generally be a violation of these rules. The use of UAS for transportation of hazardous materials could lead to serious consequences, including penalties and enforcement actions.