Industrial Union Department v. American Petroleum Institute 448 U.S. 607 (1980)

OSHA cut the benzene limit from 10 ppm to 1 ppm. But it did not first prove that the old level created a significant risk of harm. The Supreme Court said: you cannot tighten a standard just to be safe. You must show the risk and support the rule with substantial evidence.

Result: OSHA’s 1 ppm rule fell. Agencies need proof of necessity, not just caution, before imposing strict exposure limits.

• Did OSHA exceed its authority by setting 1 ppm without proving significant risk?
• Did OSHA show substantial evidence that the new limit was reasonably necessary?

• Significant Risk: OSHA must find a significant risk of material health harm at existing levels.
• Substantial Evidence: The standard must rest on solid record evidence, not speculation.
• Section 3(8) OSH Act: Standards must be reasonably necessary or appropriate to ensure safe and healthful employment.

The Supreme Court held that OSHA overstepped. Without a supported finding of significant risk, and without substantial evidence that 1 ppm was reasonably necessary or appropriate, the rule could not stand.

Congress did not give OSHA unlimited power. There must be a proven link between exposure levels and risk. The Court affirmed the Court of Appeals and set aside the 1 ppm standard.

An OSHA standard is valid only if the agency first finds a significant risk at existing levels and then adopts a limit that is supported by substantial evidence as reasonably necessary to reduce that risk.

• Sets a check on agency power—evidence before action.
• Promotes science-based health rules, not fear-based limits.
• Still protects workers by demanding proof of real risk.

1. OSHA must find significant risk at current levels.
2. New limits need substantial evidence of necessity.
3. Precaution alone is not enough for strict standards.

Mnemonic: “Prove Risk, Then Fix.”

1. Point: Find significant risk first.
2. Apply: Choose a limit backed by solid evidence.
3. Decide: If proof is thin, the rule falls.

Issue: Can OSHA set 1 ppm without proving significant risk at 10 ppm?

Rule: Standards need a finding of significant risk and substantial evidence; they must be reasonably necessary or appropriate.

Application: Record lacked proof of risk at old level; evidence did not justify 1 ppm.

Conclusion: Standard invalid; Court affirmed the set-aside.

Significant Risk

A real, non-trivial danger of health harm at current exposure levels.

Substantial Evidence

Enough reliable data in the record to reasonably support the standard.

Reasonably Necessary

A standard that fits the proven risk and is appropriate to reduce it.