How to Read an IFRA “Certificate” (UK): pick the right category, find the max %, and avoid the most common mistakes
Introduction
If you make candles, wax melts, reed diffusers, room sprays, or soaps, you’ve probably seen an IFRA document and thought: “Okay… which number actually applies to my product?” This guide shows you exactly what to look for, how to use it in real life, and where IFRA fits (and doesn’t fit) alongside UK labelling rules.
Quick answer: how to use an IFRA document in 5 steps
Match your product to the right IFRA category
Don’t guess. The category table on your document is the “menu” of product types. Your job is to find the row that matches what you’re making.
Find the “maximum usage level” (%) for that category
That % is a ceiling for that fragrance in that product type. It is not a promise of performance or scent strength.
Convert the % into grams for your batch
Example: 500g finished product × 8% max = 40g fragrance max (for that category).
Then check wax / base limits separately
Your wax (or base) may have its own maximum fragrance load. You must respect both.
IFRA helps with safe-use limits — it doesn’t “do” your CLP
In the UK, if you sell products, you still need correct hazard classification and labelling under GB CLP (or EU CLP for NI/EU).
Important: This article is practical guidance, not legal advice. Always follow your supplier documents, your base/wax manufacturer guidance, and UK rules that apply to where you sell.
What an “IFRA certificate” is (and what it isn’t)
In maker circles, people say “IFRA certificate”, but what you’ll usually be given is a Certificate of Conformity. It’s a supplier document that declares a fragrance mixture is supplied in line with the IFRA Standards for specific product categories. It’s typically issued by the fragrance manufacturer/supplier — not “handed to you” by IFRA.
Use this mental model
- IFRA max usage level (%) = the maximum safe-use limit for that fragrance in that application category.
- It’s not a performance guide (it doesn’t tell you the “best %” for throw — testing does).
- It doesn’t replace a full safety assessment or your obligations under local regulations.
IFRA is a big deal because it stops you accidentally using a fragrance too high in a product type where certain ingredients have stricter limits. But the key word is limits. IFRA does not guarantee your product will smell stronger, last longer, or “work better” at the maximum percentage. In many cases, pushing too high can cause performance issues (sweating, frosting, poor burn, separation, clogging, cloudy liquids, and more).
Where to find IFRA, SDS and allergen documents for Aroma Energy oils
If you use Aroma Energy fragrance oils (or essential oils) in products you make, you’ll want the supporting documents in one place: SDS (safety data sheet), IFRA documentation, and allergen information.
Start here
Use our document hub: CLP Regulatory Documents. It links you to the files you need.
Tip: Save the document link you use most. If you’re formulating multiple products, this alone can save you a lot of time.
Once you’ve opened the relevant file, you’re usually looking for one key table: the section that lists product categories and a max usage % for each one.
Picking the right IFRA category (candles, melts, reed diffusers, sprays, soap)
Here’s the honest truth: you don’t “pick a random IFRA %”. You match your product to the category row on your document, then use the max usage shown for that category. The category table is the decision-maker.
Quick rule: If your certificate table has slightly different wording or numbering, follow your document. The list below is a typical mapping for home fragrance makers.
| What you’re making | Typical IFRA category (often used) | Why makers confuse it | What to do |
|---|---|---|---|
| Candles | Often Category 12 | People copy a “standard load” without checking the fragrance’s actual max. | Use the cat 12 max % from your certificate, then check your wax max load too. |
| Wax melts | Often Category 12 (but check your doc) | Some suppliers treat melts and candles similarly; others may split them. | Don’t assume. If your document has a “wax melts” line, use it. Otherwise, follow supplier guidance. |
| Reed diffusers | Often Category 10A | People mistakenly use candle % (cat 12), which can be higher (or lower) than diffuser limits. | Use the diffuser category from your certificate, not the candle number. |
| Room/linen sprays | Often Category 10B | Sprays feel “similar” to diffusers, but limits can differ a lot. | Use the spray category and keep an eye on stability and inhalation sensitivity (ventilation matters). |
| Cold process soap | Often a “rinse-off” category (varies) | Soap categories can be split (hand soap vs body wash vs rinse-off vs leave-on). | Find the soap/rinse-off line and use that. If in doubt, don’t guess — ask the supplier. |
Want the quickest way to double-check yourself? Read the category wording as if you were a customer: how is the product used, and where does it end up? A reed diffuser is a continuously evaporating air freshener. A room spray is a short, airborne burst. A candle is heated wax. Different exposure patterns, different limits.
Common mistake
Makers often choose the highest percentage “because that must be the best one”. But IFRA numbers aren’t a performance leaderboard — they’re safety limits based on the intended use category.
If you also sell finished products, it’s worth building a quick “category map” document for your business: one row per product type you sell (candles, melts, reed diffusers, sprays), and the IFRA category you use for each. That alone prevents most accidental mistakes when you’re batching under pressure.
Convert IFRA % into grams (simple formulas you can reuse)
The easiest way to avoid errors is to calculate by weight (grams), not by volume. IFRA max usage is a percentage of your finished product (the total mix), unless your document states otherwise.
The core formula
Max fragrance (g) = Total finished batch (g) × (IFRA max % ÷ 100)
If your batch is 500g and your IFRA max is 8%, then the maximum fragrance is 40g.
Example 1: Candles / wax melts
Let’s say your IFRA table shows Category 12 max usage = 8% for the oil you’re using. You want to make a 500g batch of wax melts (finished product).
- Total finished batch = 500g
- IFRA max = 8%
- Max fragrance = 500 × 0.08 = 40g
Don’t forget: your wax may have a maximum fragrance load too (for performance reasons). If your wax max is 10% but IFRA max is 8%, your true ceiling is 8%. If wax max is 6% but IFRA max is 8%, your true ceiling is 6%.
Example 2: Reed diffusers
Reed diffusers are where people most often accidentally use the wrong category. If your document shows Category 10A max usage = 5%, and you’re making 200g of finished diffuser liquid:
- Total finished diffuser liquid = 200g
- IFRA max (10A) = 5%
- Max fragrance = 200 × 0.05 = 10g
If you’re learning how to get stronger reed diffuser performance without simply pushing oil higher, read: Reed Diffusers 101. It covers practical variables like reed count, flipping, bottle shape, placement and airflow.
Example 3: Room / linen sprays (and why separation matters)
Spray limits can be stricter than people expect because the exposure pattern is different. If your IFRA table shows Category 10B max usage = 2% and your finished spray batch is 500g:
- Total finished spray batch = 500g
- IFRA max (10B) = 2%
- Max fragrance = 500 × 0.02 = 10g
Quick tip for sprays
If your spray separates, clogs, or fades fast, it’s not always “low oil”. It’s often a formulation/stability issue. Start here: How to make sprays that don’t separate, and then read: DPG explained (what it does and what it won’t do).
Also, keep your expectations grounded: “stronger” isn’t always better. A spray that’s too intense can be unpleasant, and in some households it can be irritating (especially in small, unventilated rooms). Sensible ventilation is your friend.
Example 4: Cold process soap (a quick reality check)
Soap categories can vary across IFRA tables, so the calculation method matters more than the specific number: identify the correct “rinse-off” soap line, then apply the same formula by finished batch weight.
If you’re also battling “why does my soap have no scent?”, this post is relevant: Why your soap has no scent (and how to stop fading).
Safety note: IFRA max % is not a “green light” to skip basic precautions. Keep concentrates away from children and pets, avoid direct contact with eyes, and wash hands after handling oils. If you’re formulating leave-on skin products, you should be extra conservative and follow appropriate dilution guidance for the specific oil and intended use.
If you want a neat “batch calculator” habit
- Write your batch size in grams (finished product).
- Write your IFRA max % for the category you’re making.
- Calculate max fragrance grams.
- Then decide your working fragrance % (often lower than max) based on performance tests.
- Record it (date + fragrance batch + document version).
IFRA vs CLP in the UK (GB vs Northern Ireland) — keep this straight
IFRA and CLP often get lumped together, but they’re not the same thing: IFRA gives you safe-use limits by category; CLP is about hazard classification and labelling rules for chemicals/mixtures in your market.
Great Britain (England, Scotland, Wales)
- GB follows GB CLP (post-Brexit retained and amended CLP).
- Labelling and classification obligations still apply when you place products on the GB market.
- Poison centre-style submissions (NPIS) are generally treated as voluntary in GB in many cases.
If you’re building a compliance workflow, start with our: CLP labels guide.
Northern Ireland (and EU)
- Northern Ireland generally aligns with EU CLP for chemicals on the NI market.
- If you sell into NI/EU, requirements can differ from GB, so don’t assume your GB setup covers everything.
The practical takeaway: if you ship finished products to multiple regions, treat compliance as “market-specific”.
The biggest CLP mistake makers make: fragrance load vs fragrance content
This is where people unintentionally label incorrectly:
- Fragrance load is what you add (e.g., “I used 8% fragrance oil”).
- Fragrance content is how much fragrance is in the finished product after everything is included (base, additives, etc.).
Simple example
You make a 1,000g diffuser batch: 800g base + 200g fragrance oil. Your fragrance content is 20% (because 200/1000 = 0.20). If you later add an extra 100g of solvent and call it “still 20%” because you started at 20%, you’ve changed the finished product — now it’s 200/1100 ≈ 18.18%.
This matters because hazard classification and label thresholds often depend on the exact finished composition.
If you want the practical “how to label without losing your mind” version, go back to: CLP labels demystified. This IFRA guide is designed to sit beside it.
IFRA 51 in plain English (and what “current” means in 2026)
IFRA updates its Standards over time (Amendments). Many makers now talk about “IFRA 51” because it introduced changes and timelines that impacted a lot of popular fragrance types.
The 2 dates you’ll hear most
- 30 March 2024: shortened timeline for new creations (many suppliers shifted formulas by this date).
- 30 October 2025: extended timeline for existing creations to be brought into compliance.
In other words: by 2026, most reputable suppliers are working on IFRA 51 as the default. Still, always check the document version for the specific oil and batch you’re using.
The practical maker takeaway isn’t “panic about amendments”. It’s: keep your documents organised, and always formulate from the most current information your supplier provides. If you’re using older stock, don’t assume the paperwork you downloaded last year is still the latest version.
Good habit: Save your IFRA/SDS/allergen files with the date in the filename, and keep a simple record of which document version matches which finished product batch.
The 10 most common IFRA mistakes (and how to avoid them)
- Using the wrong category (most common): candle % used for reed diffusers or sprays.
- Assuming wax melts = candles without checking the table wording.
- Treating max % as “recommended %” and never testing lower.
- Ignoring wax/base limits (performance limits still apply).
- Calculating by volume instead of weight (easy to drift).
- Not reading the notes / restrictions on the document.
- Mixing fragrance load and fragrance content in your records and labels.
- Using a generic IFRA sheet that doesn’t match the exact oil/batch.
- Forgetting region differences if you sell into NI/EU and GB.
- Skipping basic safety practices (ventilation, storage, spills, exposure).
If you want to make this foolproof in your business, create a 1-page internal SOP: “For each product type we sell, we use these IFRA categories, we store documents here, and every new fragrance gets checked before first production.” It sounds boring. It’s also how you avoid expensive re-labelling later.
FAQ: quick answers to the questions makers ask most
Do I have to use the maximum IFRA percentage?
No. The max usage is a ceiling, not a target. Your working % is often lower for performance, stability, and customer comfort.
Can I use the candle (cat 12) number for reed diffusers?
Usually, no. Reed diffusers typically have their own category (often 10A). Always use the category that matches the product type on your document.
Are wax melts always the same IFRA category as candles?
Often they’re treated similarly, but not always. If your certificate has a specific wax melt line, use that. If it doesn’t, follow supplier guidance and keep documentation of the decision.
What if my wax allows 10% but IFRA allows only 6%?
Your true ceiling is 6%. You must respect the lowest limit that applies.
Why does my room spray separate if I’m under IFRA limits?
IFRA limits are about safe-use exposure by category, not stability. Separation is usually a formulation issue (solubiliser choice, ratios, mixing method, temperature). Start with our sprays that don’t separate guide.
Does an IFRA document mean my product is legally compliant in the UK?
No. It helps you stay within safe-use limits for the fragrance in a category, but you still need correct classification and labelling (CLP) for your finished product and market.
How often do IFRA documents change?
IFRA Standards are updated through amendments. In practice, suppliers update documents when formulas change or when restrictions change. The safest habit is to work from the latest supplier documents and store them with dates.
I sell in GB and Northern Ireland — do I need two setups?
Potentially, yes. Rules can differ by market. If NI/EU requirements apply to your product, treat compliance as market-specific and don’t assume your GB setup covers everything.
What if my IFRA table doesn’t list my exact product type?
Don’t guess. First, check if your product fits a closely described category by use pattern. If it’s still unclear, contact the supplier for guidance.
Where can I access Aroma Energy regulatory documents again?
Here: CLP Regulatory Documents.
References (useful official and practical sources)
These are reputable sources worth bookmarking if you’re building a compliance-friendly workflow.
- IFRA Standards overview (what IFRA is and how the Standards are used).
- Using the IFRA Standards (IFRA’s own explanation of certificates and limits).
- IFRA: Notification of the 51st Amendment (official update notice).
- HSE: CLP in Great Britain (GB CLP) (post-Brexit overview).
- GOV.UK: Submitting chemicals information to NPIS (UK guidance and context).
- HSE: Submission of information for mixtures placed on the GB market (poison centre info context).
Final thought: keep it simple, keep it documented
The best makers aren’t the ones who memorise every category number — they’re the ones who follow a repeatable process: correct category, correct max %, correct maths, and clean records. Do that, and IFRA becomes a helpful tool instead of a constant stress.
If you’re building your Aroma Energy maker setup
- Start with the Fragrance Oils collection for your scent profile.
- Use the Regulatory Documents hub to keep paperwork tidy.
- If you’re making sprays, check Spray Making Supplies and the spray stability guide.
No hype — just a clean workflow that reduces mistakes and wasted batches.
Related reads
- Aroma Energy Best Sellers Guide: How to Choose Oils and Sprays for Your Home
- How to choose home fragrance for each room
- How to Make Your House Smell Like a Spa: Clean, Subtle Home Fragrance Ideas for Every Room
Further Reading from Our Sister Brand: Vita London
If you are interested in natural wellbeing more broadly, our sister brand Vita London publishes clear, UK-focused guides on vitamins and supplements, written with the same emphasis on clarity and sensible use.
- A-Z Multivitamin: The Best Daily Supplement for Men and Women in the UK — a straightforward everyday base if you are starting from scratch.
- Morning vs Evening: When's the Best Time to Take Your Supplements? — practical timing guidance, clearly explained.
- Supplement Labels Explained: What NRV, mg, mcg and IU Really Mean — how to read what is actually in a product.
- Can You Take Too Many Supplements? — on sensible limits and not doubling up across products.
Find more wellness insights on the Vita London Blog and discover a full range of vitamins & supplements designed to support everyday health naturally.