Properly Dosing Fragrance Oil: FAQs on Candles, Soap, Diffusers & Perfume

The most common question when working with fragrances is:

"How much fragrance oil should I use?"

The technically correct answer is:

There is no universal percentage for all fragrances and all applications.

Candles, soap, diffusers, and perfumes are technically completely different product systems.

Therefore, the dosage must always be evaluated for the specific end application.

Is there a universal fragrance oil dosage?

No.

A technically sensible concentration for a candle may be unsuitable for soap, perfume, or room fragrance.

IFRA itself does not work with a blanket maximum "amount of fragrance oil for all products," but rather evaluates regulated fragrance ingredients depending on the end application. Quantitative limits refer to their concentration in the finished consumer product.

How much fragrance oil is needed for candles?

There is no universal value like:

"Candles always need 8%."

Factors to consider include:

• specific wax
• fragrance
• wick
• container
• burn performance.

Different wax products have different manufacturer recommendations. Even within the NatureWax line, there are varying load and processing instructions.

Read more: Correctly dosing fragrance oil for candles.

How much fragrance oil goes into cold process soap?

For cold process soap, the technological dosage can, for example, be related to the amount of oil/fat used.

However, it is important to distinguish between:

Formulation calculation

and

product-specific IFRA limit.

The IFRA upper limit is not an automatic dosage recommendation.

Read more: Correctly dosing fragrance oil for soap.

How much fragrance goes into Melt & Pour?

Here, in particular:

• manufacturer's recommendation for the soap base
• fragrance documentation
• own stability tests

should be considered.

The soap base may have its own maximum fragrance addition.

How much fragrance goes into a reed diffuser?

The fragrance content alone does not determine the intensity.

Also relevant are:

• base
• viscosity
• reeds
• bottle neck
• room temperature
• air movement.

Aroma Nova uses specific starting formulations for the ARDF system, which should then be tested in the final product.

Read more: Fragrance oil for reed diffusers – ARDF System.

How much fragrance goes into perfume?

The appropriate concentration depends on:

• fragrance composition
• desired intensity
• solubility
• stability
• IFRA documentation
• legal requirements

A sample recipe should therefore not be confused with a universal safety release.

What is an IFRA maximum value?

An IFRA maximum value, for quantitatively restricted materials, describes a safety-related upper limit for a regulated fragrance ingredient in the finished consumer product.

It does not mean:

"This concentration is the best formulation."

The technically optimal concentration can be significantly lower.

Is an IFRA Certificate a certification by IFRA?

No.

IFRA explicitly states that it does not itself certify individual products or fragrance mixtures. The Certificate of Conformity is issued by the manufacturer or supplier of the fragrance mixture to declare conformity with the relevant IFRA Standards for an intended use.

Therefore, a website should rather speak of:

IFRA Certificate of Conformity

or

IFRA conformity certificate

— not "IFRA certified."

Are IFRA Standards laws?

No.

IFRA describes the standards as a voluntary, globally recognized self-regulatory system of the fragrance industry; for IFRA members, they are part of the Code of Practice.

However, they do not replace national or European legal regulations.

What changed for fragrance allergens in 2026?

Regulation (EU) 2023/1545 extends the labeling of certain fragrance allergens in cosmetic products.

The relevant transition period for the first placing on the market of certain cosmetic products not adapted accordingly ended on July 31, 2026. For products covered that were already lawfully placed on the market within the transitional arrangement, there is a further period until July 31, 2028 for provision on the Union market.

Status of this information: August 2026.

Why is a separate application test necessary?

A percentage value alone does not indicate whether the finished recipe actually works.

Depending on the product, for example, the following must be checked:

Candles

• burn performance
• hot throw
• wick
• melt pool.

Soap

• thickening
• discoloration
• fragrance after curing.

Diffusers

• evaporation
• homogeneity
• fragrance release.

Perfume

• clarity
• fragrance development
• stability.

Is more fragrance oil always better?

No.

More fragrance can be:

• technically unnecessary
• sensorially too strong
• incompatible with the carrier system
• safety or regulatory unsuitable

The optimal concentration is the concentration where safety, stability, and desired fragrance effect align.

Where can I find the Aroma Nova documents?

The available:

• IFRA documents
• safety data sheets
• allergen information

can be found with the respective Aroma Nova product.

FAQ – Short answers

Is there a fixed IFRA value for all fragrance oils?

No.

Is 10% fragrance oil generally allowed?

No. This depends on the end application, fragrance, and carrier system.

Can the same fragrance be dosed equally in candles and soap?

Not automatically.

Is an IFRA maximum a recipe recommendation?

No.

Does every new product need to be tested?

For professional product development: yes.

Conclusion

The most important rule for fragrance oil dosage is:

Do not start with a universal percentage, but with the specific application.

The professional procedure is:

Define end product → check technical manufacturer specifications → check IFRA documentation → create test recipe → test application → optimize.

Professionally reviewed: Aroma Nova Product Development
Status: August 2026

Specialist sources

International Fragrance Association – IFRA Standards and Certificates of Conformity.
EU – Regulation 2023/1545 on fragrance allergens in cosmetic products.