H334 — May cause allergy or asthma symptoms or breathing difficulties if inhaled
The GHS hazard statement for respiratory sensitization, category 1 (1a, 1b). Here is what it means, the label elements that travel with it, and the substances that carry it.
What it means
Can induce allergy or asthma-like hypersensitivity of the airways after it is inhaled. Sensitized workers can react to very low exposures.
Precautionary statements paired with H334
When the engine writes SDS Section 2 for a product carrying H334, these are the precautionary statements it assigns, with combined statements written as one line:
Substances that carry H334
189 of the 4,228 substances in our database carry H334 when classified in pure form — recognizable examples:
Reference information, not legal or professional advice. Statement texts and allocations follow 29 CFR 1910.1200 Appendix C (the GHS as adopted by OSHA HazCom 2024) as implemented by our classification engine; the regulatory text and agency practice control. Claims last reviewed July 23, 2026.
The engine writes these for you.
When SDS HQ authors an SDS, it assigns the hazard statements, signal word, pictograms, and precautionary statements from these same tables — automatically, with the calculation shown.