Fragrance load and IFRA: why your max load varies
Every chandler eventually asks: why is my candle's hot throw weaker when I add more fragrance? The answer is that fragrance load is constrained on two sides. The IFRA standard caps how much of a given aroma chemical can be safely used in a candle. The wax has an absorption ceiling. Exceeding either does not strengthen the candle. It weakens it.
IFRA category 12
IFRA divides products into categories by exposure pattern. Candles are category 12, the lowest-exposure category. Many aroma chemicals are allowed at very high concentrations in category 12 (because the user is not in direct skin contact), but a meaningful minority are restricted. The fragrance house publishes an IFRA certificate per fragrance giving the maximum percentage allowed in a category 12 product.
Wax absorption ceiling
Soy waxes typically absorb 6–10% fragrance. Paraffin can hold 12%. Coconut blends often go to 12% as well. Above the ceiling the fragrance physically separates from the wax, beading on the surface and pooling in the vessel base. That free oil lowers the candle's flash point and creates a fire hazard.
Why more FO can mean less throw
Excess FO does not vaporise from the melt pool. It pools, weeps, and on a hot wick can flare. Worse, an excess load above the wick's effective melt rate produces incomplete combustion: soot, mushrooming, and a candle that smells of unburnt fragrance rather than the intended scent.
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Compatibility rules
This guide is editorial content from Waxverse, not legal advice. Verify all regulatory claims against the current text of the law and your fragrance supplier's SDS before commercial sale.