Mastering Fragrance Oil Calculation For Candle Making

Calculating the amount of fragrance oil to add to candles is an important step in the candlemaking process. Using too much fragrance oil can result in candles with dry or lumpy wax or even produce candles that do not hold a flame. This calculation is referred to as the fragrance load and is usually between 5-6% but can go up to 10%, depending on the type of candle wax used. The fragrance load is the ratio of fragrance oil to the weight of the wax. To calculate it, one must divide the desired fragrance load percentage by 100 and multiply it by the weight of the wax. For example, if you want a 10% fragrance load for 16 oz of wax, you would need 1.6 oz of oil (16 x 0.1 = 1.6).

Understanding scent load

When calculating the scent load, it's important to remember that the fragrance oil percentage is based on the amount of fragrance in the total weight of the final product, including the wax. For example, if you add 30g of fragrance oil to 300g of wax, the total weight of your product becomes 330g. This means your scent load is not 10% (30g/300g); instead, it's approximately 9.1% (30g/330g). This distinction is crucial, as using too much fragrance oil can lead to issues like tunnelling, poor scent throw, and wicks that struggle to stay lit.

To calculate the correct scent load, you can use the following formula:

Fragrance weight = Wax weight x Scent load ratio

Let's say you want to make a candle with a total weight of 300g, and you want a 10% scent load. First, calculate the weight of the fragrance oil:

Fragrance weight = 300g x 0.10 = 30g

Now, you know you need 30g of fragrance oil. To find the weight of the wax, subtract the fragrance weight from the total weight:

300g total weight - 30g fragrance weight = 270g wax weight

So, for a 10% scent load candle with a total weight of 300g, you would use 30g of fragrance oil and 270g of wax.

It's important to note that different types of wax and fragrance oils have varying abilities to hold and release fragrance. Therefore, it's recommended to start with a lower scent load, around 8%, and adjust accordingly. Additionally, always refer to the CLP (classification, labelling, and packaging) guidelines to ensure your candles comply with legal requirements, especially when selling them.

Calculating the right weights

To calculate the correct weights, you can use a simple formula:

Fragrance weight = Wax weight x Fragrance load

Here, the fragrance load is the ratio of fragrance oil to the weight of your wax, expressed as a decimal. For example, if you want a 5% fragrance load, use 0.05.

Let's walk through an example. Suppose you want to make a candle with a total weight of 300 grams, and you want a 10% fragrance load. First, calculate the weight of the fragrance oil:

Fragrance weight = 300 grams x 0.1 = 30 grams

So, you need 30 grams of fragrance oil. Now, let's calculate the weight of the wax:

Wax weight = Total desired weight - Fragrance weight

Wax weight = 300 grams - 30 grams = 270 grams

Therefore, for a 300-gram candle with a 10% fragrance load, you would need 270 grams of wax and 30 grams of fragrance oil.

It's important to note that the fragrance load percentage can affect the percentage used in CLP (classification, labelling, and packaging). This is an EU legal requirement for hazardous goods. The CLP percentage is based on the total weight of the product, including both the fragrance oil and the wax. In the example above, the CLP percentage would be calculated as 30 grams / (30 grams + 270 grams) = 9.09%.

Additionally, the type of wax you use will influence the fragrance load percentage. The fragrance load is typically between 5-6%, but it can vary depending on the specific type of candle wax. Using too much fragrance oil can result in issues like dry or lumpy wax and difficulty in maintaining a flame.

Common issues with overloaded wax

Overloading your candle wax with fragrance oil can lead to several issues. Firstly, the wick may struggle to burn properly, resulting in a small flame or, in some cases, the flame going out completely. This can cause candle tunnelling, where the wick is unable to create enough heat to melt the wax to the edge of the candle. Additionally, overloaded wax can lead to poor hot throw, as there may not be enough heat generated to release the fragrance from the wax effectively.

Another issue that can arise from using too much fragrance oil is fragrance leaching, seeping, or bleeding. This occurs when the fragrance does not bind properly with the wax and starts to separate, rising to the surface of the candle or settling at the bottom. This can also result in an oily surface or liquid forming at the bottom of the container.

To avoid these problems, it is important to calculate the correct amount of fragrance oil for your candle wax. Lowering the percentage of fragrance oil and ensuring it is well-balanced can help improve scent throw and prevent wicking issues. Additionally, pre-heating your containers and pouring the wax slowly can help reduce air bubbles and wet spots, which are common issues that can occur during the cooling process.

Using a candle calculator

To use a candle calculator, you will need to know the quantity of candles you want to make, the container size, the fragrance load percentage, and the wax gravity. The calculator will then provide you with the amount of wax and fragrance oil required for your desired candle size and quantity.

For example, if you are making four candles in 8-ounce containers, you would enter this information into the calculator. You would then select the unit of measurement (ounces, grams, or pounds) and enter the fragrance load percentage for the type of wax you are using. Finally, enter the wax gravity, which is typically around 0.86 for candlewax.

After clicking the "Calculate" button, the calculator will display the required amount of wax and fragrance oil needed to create your desired number of candles. This ensures that your candles have the correct fragrance load, which is typically between 5% and 6% for most types of candle wax. Using the correct amount of fragrance oil is crucial, as using too much can result in candles with dry or lumpy wax or even those that do not hold a flame.

CLP requirements for fragrance oil percentage

The CLP (Classification, Labelling and Packaging) regulations are an important aspect of candle-making, ensuring safety and compliance with EU and UK legislation. These regulations came into force on 1st June 2015 and apply to all mixtures entering the market, including candles. While cosmetic products are exempt, other fragranced products like candles are included as 'mixtures'.

The CLP requirements for fragrance oil percentage are based on the total weight of the candle, including both the wax and the fragrance oil. This is different from the scent load, which is calculated as the percentage of fragrance oil relative to the weight of the wax only. For example, if you have a candle with 30g of fragrance oil and 300g of wax, the scent load is 10%, but the CLP percentage is 9.09% because the total weight of the candle is 330g.

It is important to understand the difference between scent load and CLP percentage to ensure your candles are compliant with regulations and can be sold legally. The maximum recommended fragrance load for candles is 10%, but for CLP purposes, you need to calculate the percentage based on the total weight of the product.

When creating CLP labels, it is crucial to use the correct fragrance load percentage present in your product. This can be an overestimated percentage, such as a label indicating 10% when the actual value is 9%, but never an underestimated one.

The CLP label should be firmly attached to the packaging and include the following information:

• Supplier identification: Full address and phone number.
• Product identifier: Name of the product.
• EH208 Information: Information on sensitisers.
• Hazard information: Precise details of the hazards, including symbols and signal words ("Warning" or "Danger").
• Precautionary information: Safety precautions to be taken.
• Net weight of the product: The weight of the product.
• UFI Number: A Unique Formula Identifier (UFI) is required on CLP labels in the EU and Northern Ireland for products classified as health or physical hazards. This is not required in Great Britain.

By following these guidelines and correctly calculating the fragrance oil percentage for CLP purposes, you can ensure that your candles comply with the relevant regulations and provide accurate information to your customers.

Frequently asked questions