A Concentration Checklist to Run Before Submitting a CNF

I've watched more than one otherwise-solid CNF get sent back because someone typed a percentage from memory instead of checking the actual batch record. Concentration errors are the single most avoidable reason a filing gets flagged, and they're almost always caught by the same five checks done in order, every time.

Why concentration is where filings go wrong

The Cosmetic Notification Form asks for each ingredient's INCI name along with its concentration or a concentration range. That sounds simple until you remember that most formulas aren't built from raw actives, they're built from supplier blends, where your "2% preservative blend" might really be 0.4% of the actual restricted preservative once you do the math. Get that math wrong and you either under-disclose a restricted ingredient or accidentally flag your own product as non-compliant when it isn't.

The checklist

1. Confirm every trade name has been mapped to INCI

Nothing on your Batch record with a brand or supplier product name belongs on the CNF as-is. "EcoPreserve 3000" is not an INCI name. Go back to the supplier's spec sheet or safety data sheet, usually section 3, composition, and confirm the actual INCI names and CAS numbers behind it.

2. Expand every blend into its real components

If a supplier ingredient is a blend, note each component's percentage within that blend, then multiply by your use level in the finished product. A preservative blend used at 1% that's 40% phenoxyethanol by weight means phenoxyethanol is actually present at 0.4% in your finished product, not 1%. This step is where the majority of concentration errors happen, because it's tempting to just declare the blend's use level and skip the expansion.

3. Check each restricted ingredient against its Hotlist limit

Cross-reference every ingredient that might be restricted against the current Cosmetic Ingredient Hotlist. Restricted ingredients carry a maximum allowed concentration, sometimes different depending on product type (leave-on versus rinse-off, or general use versus specific product categories like oral care). Confirm your finished-product concentration sits under that ceiling, with some margin for batch variability if your process isn't perfectly consistent.

4. Make sure your declared range actually brackets your real concentration

The CNF accepts a concentration or a concentration range. If you're declaring a range rather than a single number, that range needs to genuinely bracket what's in your actual batches, including normal variation between batches, not just the number from one lab test. A range that's too narrow can put a future batch technically outside your own filing.

5. Re-verify fragrance allergen concentrations separately

Fragrance allergens need their own concentration check, independent of the general Hotlist review, since they trigger disclosure at very specific thresholds, above 0.001% for leave-on products and above 0.01% for rinse-off products. If your fragrance supplier hasn't given you a constituent breakdown, get one before filing, since guessing here is how allergens get missed entirely rather than just miscalculated.

A worked example

Say your finished product is a rinse-off body wash containing 3% of a supplier fragrance blend, and that fragrance house discloses the blend is 8% linalool and 2% limonene by weight.

Component	Blend percentage	Use level in product	Real concentration in finished product	Rinse-off threshold	Disclosure needed
Linalool	8%	3%	0.24%	0.01% (100 ppm)	Yes
Limonene	2%	3%	0.06%	0.01% (100 ppm)	Yes

Both clear the rinse-off threshold easily once you do the multiplication, even though "3% fragrance" sounds small on its own.

Common failure points, in order of frequency

1. Declaring a supplier blend's use level instead of expanding to its real components.
2. Missing a second or third CAS number for an ingredient that has more than one, leading to a mismatched Hotlist lookup.
3. Assuming a botanical extract has no restricted constituents because it "sounds natural."
4. Forgetting that concentration ranges need to cover batch-to-batch variation, not just a single reference batch.
5. Skipping the allergen-specific threshold check because it feels redundant with the general Hotlist review.

Before you actually submit

Run this checklist against your most recent production batch record, not your original recipe draft, since formulas drift over time as suppliers change or you tweak a ratio. If anything on the Hotlist review comes back close to a limit rather than clearly under it, it's worth getting a second set of eyes on the math before the filing goes in, since an amendment later costs more time than a careful pass now.

This is the exact kind of check Cosmetic Comply runs automatically once you enter your ingredients and percentages: it expands blends to real components, matches everything to INCI and CAS, and flags anything near or over a Hotlist limit with a confidence score before a human reviewer signs off and the notification goes out.