Glossary

The vocabulary of fragrance-oil formulation, in plain language. Terms link where the catalog can show you the real thing.

Fragrance load

The percentage of a batch’s total mass that is fragrance oil. A 500 g candle batch at 8% load contains 40 g of fragrance oil. Typical container-candle loads run 6–10%; the legal ceiling is per-fragrance and stated in its IFRA certificate.

Flash point

The lowest temperature at which a fragrance oil’s vapors can ignite from a spark or flame. It matters for shipping classification and for soap makers doing hot process — not for candle safety, since a wick flame far exceeds any flash point. It does not indicate scent strength.

Cold throw

How strongly a finished, unlit candle smells. Driven by fragrance load, wax type, and how well the oil bound during pouring. Good cold throw sells candles in shops; hot throw sells the second purchase.

Hot throw

How strongly a burning candle fills a room with scent. Depends on melt-pool size (wick choice), fragrance load, wax–oil compatibility and cure time. The hardest property to get right and the most common reason makers switch fragrance suppliers.

Cure time

The rest period between pouring a candle and burning it, letting fragrance and wax finish binding. Soy wax typically wants 1–2 weeks; paraffin 2–3 days. Skipping cure is the most common cause of “weak hot throw” complaints about a fragrance that performs fine.

IFRA certificate

A document the fragrance supplier publishes stating the maximum usage percentage of that specific fragrance for each IFRA product category (lip products through candles). It is per-fragrance — two vanilla oils can carry very different limits. Scentral-Park lists the published limits for every catalogued fragrance.

IFRA category

The product-type buckets the IFRA Standards use to set usage limits, based on how much skin contact the product involves. Category 1 (lip products) is strictest; Category 12 (candles, air care — no intended skin contact) is most permissive.

Wax saturation point

The maximum fragrance a wax can hold in stable solution, usually 10–12%. Loading past it does not add scent — the excess separates out (sweating), clogs the wick and increases sooting.

Sweating

Beads of fragrance oil separating from the wax surface, from exceeding the wax’s saturation point, poor stirring, or temperature swings. Cosmetic in itself, but it means the fragrance is no longer bound where it can throw.

Wick mushrooming

A carbon ball forming on the wick tip during burning, often from heavy fragrance loads or oversized wicks. Causes soot and flickering; usually fixed by wicking down or reducing load.

Top, middle and base notes

The perfumery description of how a fragrance unfolds: top notes hit first and fade fast (citrus, herbs), middle notes carry the body (florals, fruit, spice), base notes linger (vanilla, musk, woods, amber). Scentral-Park indexes catalogued fragrances by note.

Fragrance oil vs. essential oil

Fragrance oils are compounded scent formulations (synthetic and/or natural aroma materials) designed for performance and stability; essential oils are distilled or pressed straight from plant material. Fragrance oils generally throw better in candles and carry IFRA documentation; “natural” does not mean skin-safe or limit-free.

Phthalate-free

Marketing shorthand meaning the formulation avoids phthalate carrier solvents (mainly DEP). Most reputable maker-market fragrance lines have been phthalate-free for years — its absence from a label says more than its presence.

CLP label

The EU Classification, Labelling and Packaging regulation. Candles and melts sold in the EU/UK must carry hazard labelling derived from the fragrance’s allergen declaration — suppliers provide the CLP data per fragrance, usually alongside the SDS.

SDS (Safety Data Sheet)

The standardized hazard document for a fragrance oil: composition ranges, flash point, handling, transport class. Required for EU CLP labelling and useful everywhere; serious suppliers publish one per fragrance.

Vanillin discoloration

Vanillin-rich fragrances (vanilla, bakery, caramel profiles) oxidize and turn wax, soap and lotion tan-to-brown over weeks. Not a defect — plan for it with darker dyes, or pick low-vanillin alternatives.