How Concentration Ranges Work on a Health Canada CNF

Somewhere in the middle of filling out a Cosmetic Notification Form, most makers hit the same small moment of doubt: the form wants a concentration for each ingredient, but your fragrance oil is at 0.98%, and you're staring at a range bracket that starts at 1%. Do you round up? Round down? Pick the range below? It feels like a technicality, but it's worth getting right, because the whole point of the concentration field is to tell Health Canada what's actually in the bottle.

Why the CNF uses ranges at all, not just exact numbers

The Cosmetic Notification Form lets you disclose ingredient concentration as either an exact percentage or a range bracket, largely because exact formulas shift slightly batch to batch, and because some brands prefer not to disclose a precise proprietary percentage while still giving the regulator a usable ballpark. Ranges are a legitimate, accepted way to notify, as long as the range you pick actually contains your ingredient's real concentration.

The ranges exist as fixed brackets, not something you define yourself. You select the bracket that correctly contains your ingredient's actual usage level in the finished product.

Where people get it wrong

The error isn't usually picking the wrong bracket out of confusion. It's usually one of these:

• Rounding the wrong direction. If your true concentration is 0.98% and the bracket boundary is exactly 1%, you select the bracket that contains 0.98%, not the one that starts at 1%, even though it feels close enough to round up.
• Using a stale number. A maker calculates the percentage once during formulation, then tweaks the recipe later (a little more essential oil for scent strength, say) and never recalculates before filing.
• Confusing the raw material's concentration with the active's concentration. If you're using a diluted tincture or a supplier blend, the percentage that matters for the CNF is the ingredient's real concentration in your finished product, not the concentration of the raw material as it arrived from the supplier. A 10% dilution used at 5% of your formula puts the actual ingredient at 0.5%, not 5% or 10%.
• Forgetting to update the range after a reformulation. If you change your formula enough to shift an ingredient into a different bracket, that's a change worth re-filing, not something to leave on the old notification.

A worked example

Say you're notifying a body butter with shea butter, a preservative blend, and a fragrance oil.

Ingredient	Raw material use level	Real finished concentration	Bracket to select
Shea butter (Butyrospermum Parkii Butter)	Used neat at 15%	15%	Bracket containing 15%
Preservative blend (10% active in blend, used at 8% of formula)	Blend at 8% of formula	0.8% active	Bracket containing 0.8%, not 8%
Fragrance oil	Used at 0.98% of formula	0.98%	Bracket just below the 1% line

The preservative row is the one people miss most often. The number on the supplier's drum label (10% active) is not what goes on your filing. What goes on your filing is what that preservative actually amounts to in your finished jar, after you've done the multiplication.

Why this actually matters, not just as paperwork

Health Canada uses the CNF as a notification system, meaning it's a record of what's on the market rather than a pre-approval gate. But that record is only useful if it's accurate. If your fragrance oil is genuinely near a threshold that affects allergen disclosure (Canada's fragrance allergen rules apply thresholds at 0.001% in leave-on products and 0.01% in rinse-off products), getting the concentration bracket wrong could mean a disclosure requirement gets missed entirely, not just a paperwork inconsistency.

It's also just good practice for your own records. If you ever need to file an amendment because a supplier changes their preservative blend's active percentage, having accurate concentration math from the start makes that update fast instead of a full recalculation from scratch.

Getting the math right without redoing it by hand every time

This is one of the more mechanical parts of filing, multiplying blend percentages through, converting supplier numbers into real finished-product concentrations, and picking the correct bracket, and it's also one of the easiest places for a small arithmetic slip to turn into an inaccurate filing. Cosmetic Comply carries the percentage math through automatically when it expands a supplier blend into its real components, so the concentration that ends up on your notification reflects what's actually in the finished product, not what's printed on the drum label. If you're filing directly and a number sits right on a bracket edge, it's worth double-checking against Health Canada's current CNF guidance before you submit.