Concentration Limits4 min read
Do My Ingredient Percentages Need to Total 100
Why your formula's INCI percentages should sum to 100, how water q.s. handles rounding, and what actually goes wrong when they don't.
February 14, 2026Read
Concentration Limits
Reading percentages, thresholds, and where a formula tips over a limit.
Concentration Limits4 min read
Essential Oil Safe Usage Levels by Product Type
How leave-on and rinse-off products change what a safe essential oil percentage looks like, with the allergen math makers actually need.
February 14, 2026Read
Concentration Limits4 min read
Methylisothiazolinone Rinse-Off Limits You Should Know
MIT's rinse-off restriction is tighter than most preservatives, and leave-on use is effectively unworkable. Here is what soap and wash makers need to check.
February 14, 2026Read
Concentration Limits4 min read
Scaling a Recipe Up Without Breaking a Concentration Limit
Percentages should stay flat when you scale a batch, but a few common shortcuts quietly change them. Here is where that happens.
February 14, 2026Read
Concentration Limits4 min read
Use Level vs the Level Inside Your Raw Material
The percentage you weigh out and the percentage of an active substance in your finished product are two different numbers. Here is how to keep them straight.
February 13, 2026Read
Concentration Limits4 min read
Salicylic Acid Limits for Leave-On and Rinse-Off Products
Why salicylic acid's permitted level changes depending on whether your product stays on the skin or gets rinsed off, and what to check before filing.
February 12, 2026Read
Concentration Limits4 min read
Reading the Active Percent Out of a Premade Base
How to work out the real concentration of actives and preservatives already inside a ready-made lotion or cream base before you add anything.
January 23, 2026Read
Concentration Limits3 min read
Three Percentage Mistakes That Delay a Cosmetic Filing
The three concentration errors that most often get a Canadian cosmetic notification flagged, and the fix for each one.
January 16, 2026Read
Concentration Limits3 min read
BHA Leave-On Limits and Why They Differ From AHAs
Why salicylic acid and glycolic acid sit under different concentration ceilings, and how to avoid applying the wrong one.
January 14, 2026Read
Concentration Limits3 min read
Citric Acid as a pH Adjuster and Its Practical Ceiling
Why a pinch of citric acid to correct pH is a completely different regulatory conversation than an AHA exfoliation claim.
January 11, 2026Read
Concentration Limits4 min read
Why a 0.2 Percent Weighing Error Can Break Compliance
How small scale errors near a regulatory threshold can flip a compliant formula into a restricted one, and how to build in a margin.
January 9, 2026Read
Concentration Limits4 min read
How Concentration Ranges Work on a Health Canada CNF
The CNF asks for a concentration or a concentration range for each ingredient, and picking the right bracket matters most when your percentage sits near an edge.
January 8, 2026Read
Concentration Limits4 min read
Total Preservative Load When You Blend Two Systems
Combining two preservative systems in one formula means adding up every overlapping active so the total stays under each ingredient's own limit, not just checking each system alone.
January 7, 2026Read
Concentration Limits4 min read
Limonene Levels, Oxidation, and When It Must Be Declared
How limonene sneaks into citrus-scented formulas through essential oils, why it oxidizes over time, and the concentration that triggers label disclosure.
January 4, 2026Read
Concentration Limits4 min read
Citral and Eugenol Allergen Thresholds in Scented Products
How citral and eugenol behave differently in fragrance blends and why their finished-product concentration, not their source oil, decides label declaration.
January 3, 2026Read