Learning how to read IFRA usage rates for candle and soap making starts with identifying your product category, checking the fragrance oil's maximum permitted concentration, and calculating how much you can safely add to your recipe. Soap generally falls under Category 9, while candles fall under Category 12. However, those percentages are safety limits, not recommended fragrance loads.
Whether you're making your first batch of soap or developing a candle collection to sell, understanding these numbers helps you make informed decisions about fragrance concentration.
At Scented Flame Candle Supply, founder Megan White understands this firsthand. After years of making candles and searching for cleaner fragrance oils that performed well, she built a company around helping other makers find trustworthy ingredients and practical guidance.
Here's how to interpret an IFRA statement and apply those numbers to your formulations.
How to Read IFRA Usage Rates for Candle and Soap Making
The International Fragrance Association (IFRA) establishes standards for fragrance ingredients based on scientific safety assessments. These standards help determine appropriate fragrance concentrations across different consumer products.
An IFRA statement, sometimes called a Certificate of Conformity, identifies the maximum concentration of a particular fragrance mixture for its intended applications.
What Information Should You Look For?
Start by reviewing the document for four important details:
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Fragrance name and supplier information
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Document date and applicable IFRA amendment
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Product categories
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Maximum fragrance concentration for each category
The fragrance name matters because two similarly named oils can contain different ingredients and have different limits.
The document date is equally important. IFRA published its 51st Amendment guidance in July 2023, and consultation on the 52nd Amendment concluded in June 2026. Standards evolve as scientific information develops.
Before starting a new formulation, verify that you're using your supplier's current documentation.
For additional examples, Megan's article, How to Read & Use an IFRA Statement , walks through the different sections using an actual Scented Flame fragrance.
What Is the IFRA Category for Soap?
Bar soap and liquid soap intended to rinse off the skin generally fall under IFRA Category 9.
This category includes rinse-off personal care products where fragrance contacts the skin briefly before being washed away.
However, not every product marketed as soap is classified identically.
Does Cold Process Soap Have a Different IFRA Category?
Cold process and melt-and-pour soaps generally use Category 9 when they're intended as rinse-off products.
The manufacturing method doesn't automatically change the category. The product's intended use determines which category applies.
For example, imagine a fragrance has a Category 9 maximum of 5%.
In a 1,000-gram finished product, that would allow a maximum of 50 grams of fragrance, provided no other formulation restrictions apply.
That doesn't mean 5% is necessary.
Some fragrances perform beautifully at lower concentrations, while others can accelerate soap batter, discolor finished bars, or behave differently during curing.
Megan's product development experience reflects this balance. Creating a memorable fragrance requires more than finding a pleasant scent. It also means considering ingredient standards and how that fragrance performs in the intended application.
When choosing Soap Making Fragrance Oils , evaluate the IFRA documentation alongside the supplier's formulation recommendations.
What IFRA Category Are Candles?
Candles generally fall under IFRA Category 12, which covers products without intended direct skin contact.
Category 12 includes conventional candles and certain other home fragrance applications.
You might notice that some fragrance oils show a 100% maximum for this category.
That number causes considerable confusion.
A 100% Category 12 allowance does not mean you should fill your candle jar entirely with fragrance oil. It means the specific IFRA restrictions reflected in that certificate do not impose a lower concentration for that application.
Your wax still has its own fragrance-loading limitations.
For example, if your wax manufacturer recommends a maximum fragrance load of 10%, you shouldn't automatically exceed that recommendation because the IFRA certificate displays 100%.
The wax's capacity, burn behavior, fragrance performance, and applicable safety requirements must all be considered.
This distinction is especially important when selecting Candle Fragrance Oils for a new product line.
How Do You Calculate IFRA Fragrance Usage Rates?
The most important calculation is the amount of fragrance relative to the finished product.
IFRA percentages refer to the concentration in the finished consumer product, not simply the amount of wax or base ingredients.
Example: Calculating Fragrance for Soap
Suppose your fragrance has a Category 9 maximum of 4%, and your finished soap batch weighs 1,000 grams.
The calculation is:
1,000 × 0.04 = 40 grams of fragrance.
Your finished soap should contain no more than 40 grams of that fragrance under the stated limit.
For cold process soap, remember that the weight of your starting oils isn't the same as the weight of the complete formulation. Water, lye, fragrance, and moisture changes must be considered.
Example: Calculating Fragrance for Candles
Candle makers commonly calculate fragrance load relative to wax weight.
For example, adding 40 grams of fragrance to 500 grams of wax produces a wax-based fragrance load of 8%.
However, the total mixture weighs 540 grams.
The finished-product fragrance concentration is approximately 7.41%.
This difference matters when checking a restrictive Category 12 limit.
Always confirm which calculation method your recipe uses.
The safest approach is to respect the lowest applicable limit from your IFRA documentation, material specifications, and product formulation requirements.
What Is the 30/50/20 Rule for Candles?
The 30/50/20 rule is a fragrance blending guideline that suggests combining approximately 30% top notes, 50% middle notes, and 20% base notes.
It is not an IFRA safety requirement.
Top notes create the first impression. Citrus, fresh herbs, and lighter fruit fragrances often contribute brightness.
Middle notes form the main character of the fragrance, while base notes provide depth through ingredients such as vanilla, amber, musk, and woods.
For a 10-gram experimental fragrance blend, this approach would use three grams of top-note materials, five grams of middle-note materials, and two grams of base-note materials.
It's a starting point, not a mandatory formula.
In fact, Megan explains that developing Scented Flame fragrances can take months or even longer than a year. Her team works with fragrance laboratories to balance the desired scent experience with the ingredient standards behind its PureChoice line.
That development process demonstrates why blending involves more than combining pleasant-smelling oils.
When combining multiple fragrances, their individual IFRA limits cannot simply be assumed to remain valid for the new mixture. Shared restricted ingredients can contribute to the overall concentration, so a combined formulation assessment may be necessary.
How Many Candles Can You Make With 1 Oz of Fragrance?
One ounce of fragrance oil weighs approximately 28.35 grams.
The number of candles you can make depends on their actual fill weight and the fragrance percentage used.
For example, an eight-ounce candle containing approximately 227 grams of finished wax and fragrance at an 8% finished-product concentration requires about 18.1 grams of fragrance.
One ounce of oil would therefore provide enough fragrance for approximately 1.56 candles of that size.
Smaller candles require less fragrance, allowing the same bottle to stretch further.
Remember that an eight-ounce jar doesn't necessarily hold eight ounces of finished candle mixture by weight.
Measure your actual fill weight rather than relying exclusively on the container's advertised capacity.
For small businesses, these calculations also help forecast purchasing needs and avoid running out of fragrance during production.
Megan shared an example of a Scented Flame customer preparing for a major craft fair after growing from a small startup. Her team helped coordinate fragrances, waxes, jars, and delivery timing to support the customer's larger production requirements.
Accurate measurements become increasingly valuable as a candle business grows.
Why Don't My Homemade Candles Smell Strong?
A weak-smelling candle doesn't automatically need more fragrance oil.
Before increasing your fragrance load, investigate the ingredients and production process.
Common Causes of Weak Candle Fragrance
An incompatible wick can prevent the candle from developing the melt pool needed for effective fragrance release.
Adding fragrance outside the wax manufacturer's recommended temperature range may also affect incorporation and performance.
Other possibilities include insufficient curing, an unsuitable wax and fragrance combination, or a fragrance profile that doesn't perform as expected during burning.
Cold throw and hot throw should also be evaluated separately.
Cold throw describes the scent released by an unlit candle. Hot throw describes fragrance performance while the candle burns.
Megan frequently encourages makers to experiment and ask questions because the interaction between wax, fragrance, wick, and container requires testing.
Increasing fragrance beyond the recommended loading capacity can introduce performance problems rather than solve them.
Use your Fragrance Oil Safety documentation as the starting point, then adjust one formulation variable at a time.
How Much Should You Sell 8 Oz Candles For?
Your selling price should reflect the complete cost of producing and delivering each candle, not just the wax and fragrance.
Include fragrance oil, wax, wicks, containers, labels, packaging, labor, and overhead.
For example, if your total cost is $11 per candle, a $22 selling price produces a 50% gross margin before any costs not already included in that $11 figure.
Your actual price will depend on your expenses, market, and sales channels.
IFRA documentation also belongs in your production records. Consistent formulas reduce unexpected material costs and make it easier to reproduce successful batches.
How Can You Check Fragrance Safety Before Selling?
An IFRA certificate is an important formulation document, but it isn't a complete product safety approval.
IFRA specifically explains that a Certificate of Conformity doesn't replace a finished-product safety assessment or applicable national and local regulations.
The FDA also distinguishes traditional soap from cosmetic products based on composition and intended use. Products making moisturizing or therapeutic claims can fall under different regulatory requirements.
Before selling, document your fragrance supplier, current IFRA statement, ingredient quantities, batch weight, and testing results.
Review the supplier's Safety Data Sheet and any applicable labeling requirements.
Most importantly, don't assume that an IFRA-compliant fragrance guarantees a properly formulated finished product.
For more information, consult the International Fragrance Association's official standards guidance .
At Scented Flame, the goal has always been to help makers create products they can feel confident sharing with customers. Understanding fragrance documentation is one practical part of that process.
Start with the correct category, calculate your percentages carefully, and test before scaling production.
A little additional attention during formulation can prevent expensive mistakes later.