Fragrance load

The variable that most affects both the product customers buy it for and the safety of the thing you are selling.

Load is a percentage by weight

Grams of fragrance oil per hundred grams of finished candle, oil included. Six, eight, ten percent.

Weigh it. "One ounce per pound" is a ratio people carry around and it is 6.25 percent, which is often not what they think they are making.

The ceiling is set by the wax

Every wax has a maximum it will hold. Above it the oil does not bind: it pools on the surface, seeps out as sweating, or sits in the melt pool unburned.

The supplier publishes a maximum. It is a real limit and not a conservative suggestion, and exceeding it is a common cause of sweating and of a candle that smells strong cold and of nothing hot.

More is not more

Above the wax's capacity, extra oil reduces throw rather than increasing it, because unbound oil does not reach the flame.

It also changes the burn: fragrance is fuel, so a higher load usually means a taller flame, more soot and a different wick.

Which is why load is one of the six variables that force a retest. Going from 8 to 10 percent is a new candle, not a stronger one.

IFRA and the category

The International Fragrance Association publishes maximum usage levels for fragrance materials by product category, and candles fall in the non-skin-contact category.

A reputable fragrance supplier will state the IFRA maximum for candle use for each oil, and it is sometimes below the wax's capacity. Where they differ, the lower number is the one you work to.

Keep the IFRA certificate with the oil's documentation. It is the evidence that the load you chose was a decision rather than a habit.

References