Candle Fragrance: Can It Cause A Fire?

Adding fragrance to a candle is a great way to create a pleasant aroma, but using too much can be dangerous. While it may be tempting to overload your candle with fragrance oil to make the scent stronger, this could lead to a potential fire hazard. The amount of fragrance oil a wax can hold depends on the type of wax—generally, most wax blends can hold between 8 to 12% fragrance. Adding too much fragrance oil can cause it to separate from the wax, creating an ugly, gooey mess and even impacting the candle's ability to hold a wick.

The flash point of fragrance oils

The flash point of a fragrance oil is the temperature at which the oil becomes combustible if exposed to a spark or flame. Each component within a fragrance oil has its own flash point, which affects the final flash point of the oil. The lower the flash point, the more volatile the oil is, and the quicker it will turn to vapour and be lost. This is important to consider when making candles, as a low flash point could mean the fragrance evaporates before the candle has completely burned down.

When making candles, it's crucial to select fragrance oils with a flash point higher than the maximum temperature reached during the candle's burning process. This ensures the oil remains stable and does not contribute to the risk of flammability. Additionally, the flash point of the fragrance oil can determine the shipping method, as some regulatory bodies and shipping guidelines impose restrictions on flammable substances based on their flash point.

How to add fragrance oil to wax

Adding fragrance oil to wax is a fun and simple process, but it can be daunting for first-time candle makers. The amount of fragrance oil added to wax is known as the fragrance load, and it's important to add the correct amount to ensure the candle burns properly and has a strong scent throw. The fragrance load is the ratio of wax to fragrance oil, and this can vary depending on the type of wax and the desired scent strength.

Step 1: Understanding Fragrance Load

The amount of fragrance oil a wax can hold depends on the type of wax. Most wax blends can typically hold between 8% and 12% fragrance load, but it's generally recommended to stay at or under 10% to be safe. For a strong aroma, 10g of fragrance oil per 100g of soy wax is ideal. If you're looking for a more subtle scent, a percentage of 5-6% may be better.

Step 2: Measuring the Fragrance Oil

Different fragrance oils have different densities, so it's important to measure by weight rather than volume. A sensitive digital scale can help you measure weights accurately. As a general rule, use one ounce of fragrance oil per pound of wax, but this can be adjusted depending on the type of wax and personal preference.

Step 3: Adding the Fragrance Oil at the Right Temperature

Adding the fragrance oil at the right temperature will help it bind to the wax and give a stronger scent throw. The ideal temperature depends on the type of wax. For soy and paraffin wax, add the fragrance oil at 180-185°F, and for palm wax, the ideal temperature is 200-205°F. The wax is usually fully melted at around 175-185°F, and you'll want to add the fragrance oil once the wax begins to cool, at around 155-165°F.

Step 4: Stirring the Mixture

Stir the mixture for a sufficient amount of time to ensure the fragrance oil binds to the wax. Stirring for too short a time can cause the oil to settle at the bottom of the wax, resulting in a weak scent throw.

The impact of too much fragrance oil

Adding fragrance oil to a candle is a delicate art. While it might be tempting to add more fragrance oil to make a candle smell stronger, adding too much can have a detrimental effect on the candle's performance and safety.

Fire Hazard

The amount of fragrance oil a wax can hold depends on the type of wax used. Generally, most wax blends can hold between 8% and 12% fragrance. Soy candles, for example, can hold between 1% and 2% fragrance per pound of wax, while paraffin votive and pillar waxes usually hold a maximum of 1% per pound. If the wax becomes oversaturated with fragrance oil, the excess oil will sink to the bottom of the container or rise to the top of the candle, leaving the wax gooey and wet-looking. This can cause the candle to be unusable and even become a fire hazard.

Wick Problems

Adding too much fragrance oil can also cause the wick to clog, resulting in a weak scent throw. The wick may also be unable to burn hot enough to liquify the wax and fully release the fragrance, meaning the candle won't smell as strong as it should.

Poor Quality

Adding more fragrance oil than the wax can hold will also impact the quality of the candle's burn. The candle may smoke more, and the wax may not burn across the full diameter of the candle.

Uneven Distribution

If the fragrance oil and wax are not mixed thoroughly or are mixed at the wrong temperature, the fragrance may not be evenly distributed throughout the wax. This can cause the oil to separate from the wax, resulting in an uneven scent throw.

Solubility Issues

Wax and fragrance oil do not chemically bond. Instead, they form a solution or homogeneous mixture. However, if too much fragrance oil is added, the wax cannot hold the excess, resulting in syneresis (bleed). This will cause liquid drops to form on top of the candle.

Flash Point

The flash point of a fragrance oil is the temperature at which the oil can ignite when it comes into contact with an ignition source, such as an open flame. If the fragrance oil is added to the wax when it is heated above its flash point, the oil will evaporate, and the candle will lose its scent.

Testing

Due to the many variables that can affect a candle's performance, it is always recommended to test candles before mass production. This will help candle makers identify any issues with their fragrance oil load and make adjustments as needed.

The importance of testing candles

Testing candles is an important step in the candle-making process to ensure safety, performance, and quality. While it may be tempting to mass-produce candles without prior testing, this can lead to issues with the final product. Testing helps candle makers identify any potential hazards and make sure their candles meet regulatory standards and consumer expectations.

One key aspect of candle testing is fire safety. Candles that are not properly tested may pose a fire risk, which can lead to household fires and property damage. To mitigate this risk, candle makers can perform a secondary ignition test by burning the candle all the way down in 4-hour cycles to ensure that no secondary ignition occurs. Additionally, the flame height of a candle should be measured to ensure it does not exceed the safe limit of 75mm for container and pillar candles and 30mm for tea lights.

Another important aspect of candle testing is the behaviour of the candle after extinguishing. A safe candle should not spontaneously relight on its own after being blown out. Furthermore, the wick should not smoke or glow for more than 30 seconds after extinguishing. For container candles, it is crucial to ensure that the container does not crack or break during burning, as this can also pose a safety risk.

Testing candles also helps to ensure the optimal fragrance load. While adding more fragrance oil may seem like a way to achieve a stronger scent, it can actually have the opposite effect and create an unpleasant, "gooey" appearance. Testing different fragrance loads can help candle makers find the right balance between scent strength and the aesthetic of the candle.

By conducting thorough tests, candle makers can be confident that their products are both beautiful and safe for their customers. Testing helps to minimise risks, improve product quality, and ensure compliance with regulatory standards, giving consumers peace of mind that the candles they purchase are safe to use in their homes.

How to salvage an unmixed oil and wax mixture

While adding fragrance to candles, it is important to add the fragrance oil when the wax is at the proper temperature to help bind it to the wax, resulting in a stronger scent throw. The ideal temperature for adding fragrance oil is 180-185°F for soy and paraffin wax and 200-205°F for palm wax.

If you have added too much fragrance oil to your candle wax, there are a few things you can do to salvage the mixture:

• Firstly, it is important to understand that adding more fragrance oil does not always guarantee a stronger scent. In fact, adding too much fragrance oil can lead to separation from the wax, creating a potential fire hazard and affecting the scent throw.
• To fix this issue, try adding more wax to your mixture. Most waxes can hold up to 12% fragrance oil without affecting the burn, but it is generally recommended to stay at or under 10% to be safe. By adding more wax, you can dilute the excess fragrance oil and bring the ratio back into balance.
• Another option is to re-melt the wax mixture and carefully pour out some of the excess oil. This method requires precision and may be tricky, but it can help salvage your mixture.
• Additionally, you can try adding a carrier oil to your mixture. Carrier oils are odourless and can help improve the scent throw while diluting the excess fragrance oil. However, be cautious not to add too much carrier oil, as it may affect the burn of your candle.
• Finally, if you are working with small quantities, the difference between measuring by weight and volume may not be significant. However, it is always recommended to measure by weight for accurate results. Double-check your measurements and adjust accordingly to salvage your oil and wax mixture.

Frequently asked questions