A recent r/SafetyProfessionals post put it bluntly: these are literally just classes anyone can take, and yet job postings routinely list "OSHA 30 certification required" the way they’d list a degree. The post drew real agreement from safety professionals in the replies, several of whom described seeing OSHA cards weighed against actual credentials in hiring decisions. That gap between what the card legally is and how it gets used in practice is exactly why "OSHA 10 vs 30" gets searched as often as it does.
What the numbers actually mean
OSHA 10 and OSHA 30 are both OSHA-authorized outreach training programs delivered through authorized trainers -- the "10" and "30" are the minimum hours of instruction, not a skill ranking. OSHA 10 covers general hazard awareness for entry-level workers. OSHA 30 goes deeper and is aimed at supervisors, foremen, and anyone with some responsibility for other workers’ safety. Neither one is a government-issued license, and completing one does not make you "OSHA certified" in a legal sense -- OSHA itself doesn’t certify individuals this way, which is the exact real complaint the r/SafetyProfessionals thread was making.
Construction or General Industry -- pick the right track
Both courses come in two versions: Construction (29 CFR 1926) and General Industry (29 CFR 1910). If your job is on a construction site, you need the Construction track; if you work in a fixed facility -- a warehouse, plant, or shop -- you need General Industry. Taking the wrong track is a common, avoidable mistake that can mean redoing the training for a specific contract or job site requirement.
Where it’s actually required
There’s no single federal law requiring OSHA 10 or 30 for most private-sector work. What actually drives the requirement is a patchwork of state laws, city ordinances, and public-works contract terms -- Connecticut, Massachusetts, New York, Nevada, Missouri, and New Hampshire all have real statutory requirements tied to public construction work, and many general contractors require it site-wide even where the law doesn’t. Check your state and your specific contract before assuming either card is optional.