Logging Ingredient Percentages So Your CNF Adds Up

Open ten small-batch makers' formula sheets and you will find ten different systems, half of them in drops, some in ounces, a couple that do not actually sum to 100 percent when you add up the column. None of that is a problem until you sit down to file a CNF and realize your percentages do not reconcile with what is actually in the bottle.

Start from the batch, not the recipe

The cleanest way to get percentages right is to work backward from an actual production batch, weighed in grams, rather than forward from a recipe written in cups and drops. Weight-by-weight percentage only means something when everything is on the same scale.

Say you make a 1000 gram batch of lotion. Your log should look like this:

Ingredient	INCI name	Grams in batch	Percentage (w/w)
Water	Aqua	700	70.0%
Cetearyl alcohol blend	Cetearyl Alcohol	40	4.0%
Sunflower oil	Helianthus Annuus Seed Oil	150	15.0%
Glycerin	Glycerin	50	5.0%
Preservative blend	(expand to components)	10	1.0%
Fragrance	(expand to components)	20	2.0%
Vitamin E	Tocopherol	5	0.5%
Xanthan gum	Xanthan Gum	5	0.5%
Citric acid (pH adjust)	Citric Acid	20	2.0%
Total		1000	100.0%

If your column does not sum to 100, something is missing or double counted, and that error will follow you straight into your notification if you do not catch it here.

Expand blends before you finalize the sheet

Notice the preservative blend and fragrance rows above are flagged for expansion. Supplier blends are a single line item on your invoice but multiple INCI ingredients in reality. If your preservative blend is 1 percent of your formula and the supplier's documentation says it is 60 percent phenoxyethanol and 40 percent ethylhexylglycerin, your real concentrations are 0.6 percent phenoxyethanol and 0.4 percent ethylhexylglycerin in the finished product, not 1 percent of an unnamed blend.

This step matters even more for fragrance, since fragrance blends can contain allergen components at levels relevant to the disclosure thresholds coming into effect this year. List 1 fragrance allergens become mandatory on the CNF and label on April 12, 2026, and List 2 follows on August 1, 2026, with disclosure triggers above 0.001 percent in leave-on products and above 0.01 percent in rinse-off products. You cannot know whether a fragrance allergen crosses that threshold unless you have expanded the fragrance blend down to its individual components first.

Ranges, not just single numbers

Health Canada's CNF allows ingredients to be listed by concentration or by a concentration range, which is useful if you tweak a formula slightly batch to batch, say your fragrance load varies between 1.8 and 2.2 percent depending on the fragrance house's recommendation. Decide up front whether you are filing a fixed percentage or a range, and if you choose a range, make sure your actual production batches never drift outside it. A range on paper that your real batches regularly exceed is not a technicality, it is a formula that no longer matches its own filing.

A habit that prevents the most common error

The single most common percentage error is forgetting to account for water lost during processing, particularly in products that involve heating, like lotions cooked on a stove or double boiler. If your recipe calls for 700 grams of water but 15 grams evaporate during the heating phase, your finished batch weight is 985 grams, not 1000, and every other ingredient's real percentage just shifted slightly upward. Weigh your finished batch, not just your starting ingredients, and calculate percentages from the actual final weight.

Keep one master sheet per formula version

Every time you adjust a formula, even slightly, save a new version of this sheet rather than overwriting the old one. When you eventually decide whether a change needs a CNF amendment or a new notification, having the old and new percentage sheets side by side makes that comparison fast instead of a memory exercise.

Cosmetic Comply takes exactly this kind of percentage sheet as your starting input, expands any supplier blends into their real components automatically, and checks the resulting concentrations against restricted-list limits before a compliance reviewer signs off, so the arithmetic step stops being the part of filing that eats your afternoon.