IFRA Category Use Levels and Your Leave-On Products

Someone asked me why their fragrance supplier kept asking "what category is this for" before quoting a max use level, as if the same fragrance oil has a different safe percentage depending on what you're putting it in. It does, and that's the entire logic behind IFRA's category system.

IFRA, the International Fragrance Association, sets maximum use levels for fragrance materials based on how a product actually contacts skin, not based on the fragrance material alone. The same rose absolute might be capped at one percentage in a body lotion and a completely different percentage in a rinse-off shampoo, because the exposure profile is nothing alike. A leave-on lotion sits on skin for hours. A shampoo is on your scalp for maybe two minutes before it goes down the drain.

Why category matters more than most people assume

If you ask a fragrance house for "the max use level" without specifying the category, you'll get a number back, but it might be the wrong number for your actual product. Suppliers structure their fragrance compliance documentation around IFRA's categories precisely because a single fragrance oil can carry multiple different max percentages depending on the finished product it ends up in.

This is why the category you tell your supplier matters as much as the fragrance itself. Get the category wrong and the "safe" percentage they quote you may not actually be safe for what you're making.

Broadly, how the categories split

IFRA's categories are organized around exposure type and contact duration. Without reproducing the full technical breakdown (which is worth pulling directly from IFRA's current standard, since these get updated), the broad logic looks like this:

Exposure type	Typical products	General use-level pattern
Leave-on, large skin area, extended contact	Body lotion, body oil	Lower max percentages
Leave-on, smaller area or shorter contact	Face cream, deodorant	Varies by sub-category
Rinse-off	Shampoo, body wash, soap	Higher max percentages generally allowed
Lip products	Lip balm, lipstick	Its own tighter category given ingestion risk
Fine fragrance	Perfume, cologne	Its own category with different logic entirely

The key habit is not memorizing exact percentages, since those get revised, but always identifying your finished product's actual category before you accept a use level from a supplier.

Where suppliers and makers talk past each other

A fragrance house will typically hand you a certificate or a safety data sheet that lists a maximum use level for a named category, or sometimes for several categories at once. The mistake happens when a maker takes the highest number listed, because it's the number they want to see, without checking that it actually corresponds to their product type.

Say a fragrance oil is certified at 0.8% max for rinse-off products and 0.3% max for leave-on products. If you're making a lotion, using this fragrance at 0.6% because that number appeared somewhere on the paperwork puts you double the actual safe leave-on level, even though 0.6% is genuinely a number the supplier documented, just for the wrong category.

What to actually ask your supplier

• What IFRA categories does this certificate cover, and what's the max use level specifically for a leave-on lotion or cream, not just the highest number listed
• Does the certificate reflect the current IFRA amendment, since these standards get updated periodically
• What's the allergen breakdown of this fragrance blend, broken out individually, so you can carry those percentages through into your own finished-product calculation

That last question connects directly to your fragrance allergen disclosure obligations in Canada, since the allergen percentage in your finished product depends on both your fragrance load and the blend's own composition. IFRA use levels and allergen disclosure thresholds are two separate checks, and passing one doesn't mean you've cleared the other.

Keeping this straight across a product line

If you're running several products using the same fragrance oil at different use levels, a spreadsheet mapping each SKU to its category and its actual fragrance percentage saves a lot of guesswork later, especially when you're reformulating or a supplier updates their certificate.

This is one of the areas where Cosmetic Comply's ingredient mapping earns its keep, since it carries the math through from supplier blend percentage to finished-product concentration automatically, which is exactly the calculation that goes wrong most often when it's done by hand across a growing product line.