Final answer:
The minimum refrigerant container size for sale to Section 608 certified technicians is 20 pounds, as regulated by the EPA to protect the environment.
Step-by-step explanation:
The smallest container size in which refrigerant may be sold to Section 608 certified technicians is 20 pounds. This regulation is enforced by the Environmental Protection Agency (EPA) to prevent the release of refrigerants into the atmosphere due to their potential to harm the ozone layer and contribute to global warming. Technicians certified under Section 608 of the Clean Air Act are trained in the proper handling, recovery, and recycling of refrigerants.