Understanding IFRA Category 4 Limits
What IFRA Category 4 means, why it applies to fine fragrance, and how to read the limits in your formula.
What is Category 4?
IFRA splits finished products into 12 categories based on skin exposure. Category 4 covers hydroalcoholic products applied to areas not directly on the face — the classic eau de parfum and eau de toilette space.
Why limits exist
Some materials are restricted because of skin sensitization, phototoxicity, or systemic exposure concerns. The limit is the maximum concentration allowed in the finished product — not in your concentrate.
Reading a limit
If a material has a Category 4 limit of 2.0%, that means the final perfume (after dilution to typical 15–20% concentrate) can contain at most 2% of that material.
Using Scent Inventory
When you enter a CAS number on a material, Scent Inventory looks up the Category 4 limit automatically and warns you in the formula editor if your dose exceeds it.