State and local regulations regarding refrigerants must be followed with federal law and may be stricter.

• A. Are optional
• B. Have to be followed with federal law and may be stricter
• C. Override federal law
• D. Do not apply to refrigerants

Answer: (B)

Regulations at the federal level set the baseline for how refrigerants must be handled, recovered, labeled, and reported. State and local rules can add extra requirements on top of those federal standards. You must follow both: meet the federal requirements and also any stricter state or local rules. Federal law provides the minimum, and state or local regulations can tighten them without replacing them. That’s why this statement is the best fit: you have to follow federal law and it may be stricter at the state or local level. The other options aren’t correct because compliance isn’t optional, federal rules aren’t simply overridden by state rules, and refrigerant regulations do apply at multiple levels.