Category: Advice / Law and CLP | Reading time: 8 minutes
Introduction
You're browsing fragrance oils in our store and next to each one, you see a number – e.g., "Classification threshold: 4.6%" or "Classification threshold: 10%". What does this mean? Why does one oil have 2% and another 30%? And how does this affect your candle?
This article will simply explain what the classification threshold is, how to read it, and how to use it to consciously select the fragrance oil concentration – so you know how much paperwork awaits you BEFORE you pour your first candle.
1. What is a classification threshold?
The classification threshold is the maximum concentration of fragrance oil in wax at which your candle does not require CLP pictograms, a UFI code, or a PCN notification.
In other words: if you use the oil at a concentration below the threshold – your candle is either completely "clean" (no classification), or it requires at most an informative EUH208 statement (one line of text on the label, no pictograms, no UFI).
If you exceed the threshold – the candle is classified as hazardous. The label will feature GHS pictograms, the "WARNING" signal word, H and P statements, a mandatory UFI code, and a notification to poison control centers (PCN). More work, more costs.
The threshold is your decision boundary. Knowing it allows you to choose consciously: whether you want a simpler path (below the threshold) or a stronger scent with full documentation (above the threshold).
2. Why does each oil have a different threshold?
Because each oil has a different chemical composition. Vanilla oil contains different substances than cinnamon, citrus, or floral oils. And each of these substances has its own CLP classification and hazard thresholds.
Example from our offer:
| Oil | Classification threshold | At 6% oil | At 10% oil |
|---|---|---|---|
| Chocolate & Cocoa Bean | ~10% | No classification | Borderline EUH208 |
| Citrus oil (example) | ~4.6% | H317 + pictograms + UFI | H317 + pictograms + UFI |
| Spicy-herbal oil (example) | ~1.75% | H317 + H412 + UFI | H317 + H412 + UFI |
The same percentage of oil (6%), the same wax – but completely different legal consequences. Chocolate & Cocoa Bean at 6% is completely clean. Citrus oil at 6% requires full documentation. That's why there is no universal "safe concentration".
3. What exactly does our threshold cover?
This is our advantage, and it's worth understanding. The threshold we provide for each oil is the lowest threshold among ALL hazard classes – not just sensitization.
Most guides and competing stores (if they provide thresholds at all) only look at sensitization (H317). We check:
- Skin sensitization (H317) – the most common problem in candles
- Environmental toxicity (H410, H411, H412) – often overlooked, but can be limiting!
- Skin irritation (H315) – rare in candles, but we check
- Eye irritation (H319) – same as above
- Acute toxicity (H302, H312) – same as above
Why is this important? Because it happens that an oil has a sensitization threshold of 2.28%, but an environmental threshold (Aquatic Chronic 3, H412) of 1.75%. Someone who only looks at sensitization and uses 2% oil thinks they are "clean" – but in fact, from 1.75% they are already obliged to apply environmental labeling.
Our threshold accounts for this pitfall. You look at one number – and you can be sure.
4. How to read the threshold - three zones
For each oil in the store, you will see a classification threshold. Here's how to interpret it:
Green zone: below threshold
Your candle does not require CLP pictograms, UFI, or PCN. You might need an EUH208 statement (one line on the label – "Contains: [substance]. May produce an allergic reaction."), but this is the minimum of formalities. No pictograms, no extra costs.
Yellow zone: around the threshold
You are close to the limit. A small change in concentration can move you from a "clean" candle to a "hazardous" one. Consider reducing the concentration by 0.5-1 percentage point to have a safety margin. Our thresholds are calculated pessimistically (at the upper limits of the ranges from the Safety Data Sheets), so the actual threshold might be slightly higher – but it's better not to risk it.
Red zone: above the threshold
The candle is classified as hazardous. GHS pictograms, the "WARNING" signal word, and H and P statements appear on the label. You need a UFI code and a PCN notification. This is fully legal – but it requires more work and costs (125 PLN for PCN notification through our partner Chemtra). You have a ready SDS from TopWosk, so at least the documentation is taken care of.
5. Pessimistic threshold – what does it mean?
We calculate our thresholds based on a pessimistic scenario – i.e., the upper limits of the concentration ranges from the oil Safety Data Sheets.
What does this mean in practice? The Safety Data Sheet provides the concentration of a substance in ranges, e.g., "linalool: >=1% - <5%". We take 5% (the upper limit). The oil manufacturer knows that the linalool content is, for example, 2.3% – but they don't tell us this in the SDS, only in a separate allergen list.
The effect: our threshold is conservative. If you stay below it – you have 100% certainty of safety. The actual threshold (calculated with precise data from the allergen list) might be higher – but never lower.
This is a conscious choice. We prefer to give you a threshold you can trust, rather than a threshold that is "probably OK".
6. Specific scenarios – how it works in practice
Scenario 1: "I want the simplest path"
You choose oils with a high threshold (e.g., 8%+) and use a 6% concentration. Your candle is clean or has at most EUH208. Zero pictograms, zero UFI, zero PCN. Minimum formalities - you download the SDS, fill in the data, print the label from the generator, and sell.
Scenario 2: "I want a stronger scent, I accept the formalities"
You like this particular oil and want to use it at 10%, but the threshold is 4.6%. The candle will be classified with H317. OK – you have a ready SDS from TopWosk for 10%, the label generator will automatically select pictograms, and you commission the PCN to Chemtra for 125 PLN. More work, but doable.
Scenario 3: "I have 20 fragrances - how to optimize this?"
You look at the thresholds for all 20 oils. 15 of them have thresholds above 6% - you make these at 6% concentration, no formalities. 3 have thresholds of 3-5% - you make these at 3% concentration, still clean. 2 have thresholds below 2% - you decide if it's worth it (if the scent is a bestseller - yes, 125 PLN for PCN will pay off). Instead of 20 PCN notifications, you do 2. Savings: 2,250 PLN.
7. Most Frequent Questions
"Threshold 4.6% - can I use exactly 4.6%?" - Technically yes, but we don't recommend it. Always leave a margin at the boundary (e.g., 4% instead of 4.6%). Slight fluctuations in weighing can push you over the threshold, and then the entire classification changes.
"Does the threshold change if I use different wax?" - Our thresholds are calculated for soy wax (not classified as hazardous). If your wax is also not classified - the thresholds are the same. If the wax has its own classification - contact us.
"Why don't you provide thresholds for EUH208?" - The EUH208 threshold (0.1% of a single sensitizing substance in a candle) is usually lower than the classification threshold and depends on the specific substance. At typical concentrations of 6-10%, most oils will have at least EUH208. Our classification threshold tells you the limit beyond which a candle requires pictograms on the label - this could be sensitization (H317), environmental hazard (H412), or another class. Below the threshold = no pictograms and no UFI/PCN. Above the threshold = check your SDS for specific obligations (because, for example, environmental classification itself requires labeling, but not UFI).
"Will the threshold change if the manufacturer changes the oil composition?" - Yes. That's why we update our thresholds when we receive new Safety Data Sheets from the manufacturer. If the composition changes - we will let you know.
"Can I calculate the threshold myself?" - Yes, if you have knowledge of CLP. You need section 3 of the oil's SDS and knowledge of CLP calculation methods. We described the method in the article on CLP classification step-by-step. But you don't have to - we provide ready thresholds.
Summary
The classification threshold is a single number that tells you everything: how much oil you can add to the wax before your candle requires pictograms, UFI, and PCN. Below the threshold - minimal formalities. Above - full documentation.
Three things to remember:
- Each oil has a different threshold - there is no universal "safe concentration"
- Our threshold considers ALL hazard classes - not just sensitization, but also environment, irritation, and toxicity
- The threshold is pessimistic = safe - if you stay below, you are certain
Check the classification thresholds for our oils and choose consciously. Ready SDSs in three concentrations are available for download. View the fragrance oil collection →