How to Read a Supplier Allergen Declaration Sheet

Every fragrance and essential oil supplier hands you some version of an allergen declaration sheet, and most makers glance at it, see a wall of chemical names and percentages, and file it away without really reading it. That's a mistake, especially now, since Canada's fragrance allergen disclosure rules are becoming mandatory on a set timeline and the sheet in your inbox is exactly what you need to comply.

What's actually on the page

A typical IFRA-style allergen declaration lists individual allergen substances the fragrance or essential oil contains, usually with:

• The INCI name or common chemical name for each allergen
• A CAS number, since some substances have more than one valid CAS number and the sheet should specify which one applies to that entry
• A percentage or concentration of that allergen within the fragrance or oil itself, not within your finished product yet
• Sometimes a note on natural origin, since many of these allergens occur naturally within essential oils rather than being added separately

The math step everyone skips

The percentage on the supplier sheet tells you how much of that allergen is in the fragrance oil or blend itself. It does not tell you how much is in your candle, lotion, or soap. You have to carry that number through your own formula.

Say a fragrance oil declaration lists Linalool at 3% within the oil, and you're using that fragrance oil at 1% in your lotion. The real concentration of Linalool in your finished product is 3% times 1%, which works out to 0.03%, or 300 ppm. That's the number that matters for disclosure thresholds, not the 3% printed on the supplier sheet.

Why the threshold math matters right now

Canada is phasing in mandatory fragrance allergen disclosure on the Cosmetic Notification Form and the label itself. List 1, the original core set of fragrance allergens, becomes mandatory on April 12, 2026. List 2, an expanded set aligned with international allergen lists, becomes mandatory August 1, 2026. The disclosure triggers are:

Product type	Disclosure trigger
Leave-on products	Above 0.001% (10 ppm)
Rinse-off products	Above 0.01% (100 ppm)

Using the Linalool example above, 300 ppm in a leave-on lotion is well above the 10 ppm leave-on trigger, so it needs to be disclosed. The same 300 ppm in a rinse-off product would still clear the 100 ppm rinse-off trigger too. Those thresholds are genuinely low, which is exactly why skimming the supplier sheet instead of doing the math causes people to under-disclose without realizing it.

Common allergens you'll see repeatedly

A handful of names show up on almost every fragrance and essential oil declaration sheet, because they occur naturally in so many aromatic plants:

• Limonene (common in citrus oils)
• Linalool (common in lavender and many florals)
• Citronellol
• Geraniol
• Eugenol (common in clove)
• Coumarin

If you're working with essential oils rather than synthetic fragrance blends, don't assume "natural" means allergen-free. Several of these compounds are naturally occurring constituents of the oils themselves, so a 100% natural essential oil blend can still trigger disclosure obligations just like a synthetic fragrance compound would.

A short checklist for reading any declaration sheet

1. Confirm each allergen's INCI name and CAS number match what you expect, since sheets occasionally use trade jargon or outdated names.
2. Note the percentage within the fragrance or oil, not assume it's the final product percentage.
3. Multiply by your actual use level of that fragrance or oil in the finished formula.
4. Compare the resulting ppm figure against the leave-on or rinse-off trigger relevant to your product type.
5. Keep the supplier sheet on file. It's your evidence trail if anyone questions your disclosure decision later.

Doing this by hand for every SKU with a fragrance blend gets tedious fast, especially once you're tracking List 1 and List 2 allergens across a full product line. This is one of the areas where Cosmetic Comply's ingredient matching earns its keep, since it carries supplier blend percentages through to real finished-product concentrations automatically and checks them against the applicable allergen disclosure thresholds as part of the Canadian filing.