Flash Point Defined
Flash point is the lowest temperature at which a liquid gives off enough vapour to ignite when exposed to an open flame.
For fragrance oils, this typically ranges from 65°C to 93°C (150°F to 200°F).
The Common Misconception
Many candle makers think: "I can't add fragrance above its flash point or it'll catch fire."
This isn't quite right.
Flash point means the vapour can ignite if there's an open flame present. In a closed melting pot with no flame nearby, you're not at risk of fire just because the wax is above the fragrance's flash point.
What Actually Happens Above Flash Point
When you add fragrance to wax that's significantly above the flash point:
- More volatile compounds evaporate into the air
- You lose some of the "top notes" (the first scents you smell)
- Overall scent throw may be slightly reduced
You're not creating a fire hazard. You're just wasting fragrance.
The Real Safety Concern
The actual fire risk with fragrance oils is:
- Spilling oil near an open flame
- Overheating wax until it smokes (around 120°C+)
- Leaving heating equipment unattended
Flash point matters more for storage and shipping than for the actual candle-making process.
Practical Guidelines
Add fragrance at 75-80°C for most waxes. This is below most fragrance flash points and warm enough for good binding.
Never heat wax above 100°C. There's no benefit, and you risk scorching the wax and degrading fragrance.
Stir for 2 minutes after adding fragrance. This ensures even distribution and proper binding.
Reading Fragrance Specs
When you buy fragrance oils, you'll see flash point listed. Use it as a guide:
- Below 65°C: Very volatile. Add at the lower end of your temperature range.
- 65-80°C: Typical range. Standard adding temperature works fine.
- Above 80°C: Less volatile. Can handle slightly higher adding temps.
Most quality candle fragrance oils are formulated with flash points that work well with standard candle-making temperatures.