How to use essential oils safely in candle making?

Essential oils for candles: are they really safe?

Imagine the warm ambience of a handmade or homemade candle diffusing the natural aromas of lavender or ylang-ylang. Seductive, isn't it? Yet behind this idyllic image lies a more complex reality that many artisanal candle makers are unaware of.

Essential oils, those aromatic concentrates extracted from plants, offer an attractive alternative to synthetic fragrances. But did you know that some can ignite at surprisingly low temperatures? Or that their chemical composition can change under the effect of heat?

In this comprehensive guide, we demystify the use of essential oils in candles, revealing the safe practices that experts apply. Whether you're an enthusiastic novice or a seasoned artisan, you'll discover why not all essential oils are created equal when it comes to incorporating them into candle wax.

Essential oils in candles: benefits and considerations

The appeal of essential oils in candle-making is undeniable. These natural extracts offer not only authentic fragrances but also aromatic properties that can positively influence our mood and well-being. However, contrary to popular belief, their use is not without risk.

Why do so many designers turn to essential oils to scent their candles?

There are many reasons, often linked to a search for authenticity:

• Natural option: Extracted directly from plants, essential oils represent an alternative to synthetic fragrances, especially when they are organically grown.
• Aromatic properties: Certain essential oils, such as True Lavender or Eucalyptus radiata, are recognized for their relaxing or stimulating effects.
• Customization: unique blends can be created to suit users' olfactory preferences
• Air purification: Some essential oils have antiseptic properties that can help to purify the air in a room.

The specific challenges of essential oils in candles

Unlike synthetic fragrances specially designed for candles, essential oils have several characteristics that complicate their use:

• Variable volatility: Some top notes evaporate very quickly.
• Heat sensitivity: aromatic molecules can degrade at high temperatures
• Flammability: Flash points vary considerably from one essential oil to another.
• Concentration required: Often higher than synthetic fragrances for an equivalent olfactory result.

However, with the right knowledge and techniques, these challenges can be overcome.

 

Critical points: the notion of flash point

One of the fundamental concepts to master when using essential oils in candles is that of the flash point. This notion is crucial to both the safety and effectiveness of your creations.

What is the flash point and why is it so important for your candles?

The flash point is the lowest temperature at which a liquid gives off enough vapor to ignite on contact with a source of ignition. In simple terms, it's the temperature at which essential oils become flammable.

When making candles, we generally recommend using essential oils with a flashpoint above 65°C. Why is this? Because the temperature of a candle's molten wax is generally between 60 and 80°C.

How does flash point affect the safety of your creations?

When you add an essential oil to hot wax, three scenarios can occur depending on its flash point:

1. Flashpoint too low (< 60°C): the essential oil can ignite instantly on contact with the wax, creating a fire hazard
2. Medium flash point (60-65°C): The essential oil does not ignite immediately, but may create an unstable candle with a risk of ignition on combustion.
3. Adequate flash point (> 65°C): The essential oil mixes with the wax without risk of ignition, creating a safe, stable candle.

A safety margin of at least 5-10°C between the flash point of the essential oil and the temperature of the wax is therefore strongly recommended.

Flash points of some common essential oils

Essential oil	Flash point (°C)	Candle safety
Fine lavender(Lavandula angustifolia)	71°C	Excellent ✓
Cinnamon(Cinnamomum verum)	88°C	Excellent ✓
Tea Tree(Melaleuca alternifolia)	58°C	Medium ⚠
Eucalyptus globulus(Eucalyptus globulus)	44°C	Not recommended ✗
Lemon(Citrus limon)	53°C	Not recommended ✗
Patchouli(Pogostemon cablin)	116°C	Excellent ✓
Ylang-Ylang(Cananga odorata)	78°C	Excellent ✓

These significant variations in flash points explain why not all essential oils are suitable for candle-making. Using an essential oil with too low a flash point can not only alter its aromatic properties but also present a flammability risk.

Appendix 3 below provides a more complete list, in descending order, of the flash points of essential oils, their compatibility with candles and their aromatherapeutic qualities.

How to calculate the flash point of an essential oil blend

If you want to create a customized blend of essential oils for your candles, you need to estimate the resulting flash point. To do this, you can use this weighted average formula:

(Volume HE A × Flash point HE A) + (Volume HE B × Flash point HE B)

-----------------------------------------------------------------------------------------------

Total volume of mixture

 

Practical example: for a 5 mL mixture of 2.5 mL sweet orange(Citrus sinensis) essential oil (flash point: 48°C) and 2.5 mL cinnamon (flash point: 88°C):

(2.5 mL × 48°C) + (2.5 mL × 88°C) = 120 + 220 = 340/5 = 68°C

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5 mL 5

 

The estimated final flash point of the mixture is 68°C, making it suitable for candle-making.

 

Practical steps for incorporating essential oils into your candles

This section guides you step-by-step through the process of incorporating essential oils into your creations, focusing on the technical aspects essential to success.

What is the ideal dosage of essential oils in wax?

Dosage is crucial not only for fragrance intensity, but also for safety and burn quality:

• Standard dosage: 5-6% of the total weight of the wax (i.e. around 30 drops for 500g of wax).
• For a light fragrance: 3% of wax weight
• For a stronger fragrance: up to 6% maximum

Caution: an overdose may affect the candle's ability to burn properly and potentially create an unstable flame. Unlike synthetic fragrances, which work well at 2-3%, essential oils often require a higher percentage for optimal diffusion.

At exactly what temperature should essential oils be added?

The temperature at which you add essential oils is crucial to preserving their aromatic properties and avoiding the risk of inflammation:

1. Melt your wax in a bain-marie
2. Immediately remove the container from the heat source once the wax has completely melted
3. Allow to cool to a temperature of around 55-60°C (always below the flash point of your oils).
4. Add your essential oils and stir carefully for at least one minute to ensure even distribution
5. Quickly pour into the containers prepared with the wicks

For more information on the different waxes suitable for essential oils in candles, please see Appendix 2 below.

How to test the distribution of essential oils in your wax?

Before producing candles in quantity, perform this simple test:

1. Prepare a small sample of wax with your essential oils, as described above.
2. Pour it into a small transparent container
3. After solidification, observe whether any oil "pockets" have formed (a sign of poor incorporation).
4. Light the sample and evaluate :
   • Fragrance intensity, cold and hot
   • Flame stability
   • How the wax melts (ideally, a uniform wax bath)

This methodical approach will enable you to adjust your formulations before larger-scale production.

 

Precautions and potential risks

Safety must always be your priority when using essential oils in candles. This section addresses potential risks and essential preventive measures.

Are essential oils in candles toxic?

Scientific research suggests that essential oils in candles are generally of low toxicity when the instructions for use are followed. According to Gigon (2019), when used in ambient air as recommended, essential oils present a satisfactory tolerance.

However, certain specific risks do exist:

• Volatile organic compounds (VOCs): Essential oils release VOCs which, in excessive concentrations, can irritate the respiratory tract.
• Chemical transformation: Heat can modify certain aromatic molecules, potentially creating irritating compounds.
• Allergens: Some essential oils contain natural allergens that can trigger reactions in sensitive individuals.

What precautions should be taken to ensure safe use?

To minimize risks while enjoying the benefits of essential oils:

• Adequate ventilation: Make sure the room is well ventilated when using essential oil candles.
• Limited exposure time: Do not burn candles for extended periods (no more than 3-4 consecutive hours).
• Sensitive populations: Children, pregnant women, asthmatics, epileptics and pets may be more vulnerable to the effects of essential oils.
• Preliminary test: If you are prone to allergies, first light the candle in a well-ventilated room for a short period to assess your tolerance.

How to recognize an adverse reaction to essential oils?

Be alert to the following symptoms when using essential oil candles:

• Headaches or dizziness
• Irritation of the eyes, nose or throat
• Difficulty breathing or chest tightness
• Nausea or malaise

If these symptoms occur, extinguish the candle immediately, ventilate the room and go outside for fresh air.

 

Alternatives to essential oils: Grasse fragrances

Faced with the challenges posed by essential oils, many professional candle makers are turning to Grasse fragrances, specifically designed for this purpose. These fragrances offer several advantages:

• Superior thermal stability
• More consistent, longer-lasting fragrance delivery
• Greater variety of scents available
• Tested for safety during combustion
• Generally more economical

The choice between essential oils and Grasse fragrances will depend on your priorities: if you're primarily looking for natural aromatic properties, essential oils may be appropriate despite their limitations. If performance and consistency are your priorities, specialized fragrances are often a better option.

If you've read this far, you're interested in the natural properties of essential oils. For more information, please see Appendix 1 below for a more detailed comparison between essential oils and Grasse perfumes.

 

Selecting the right essential oils for candles

To maximize the safety and effectiveness of your scented candles, here is a selection of recommended essential oils with a sufficiently high flash point:

• Fine lavender(Lavandula angustifolia) (71°C): Relaxing and soothing
• Patchouli(Pogostemon cablin) (116°C): Earthy and deep
• Cinnamon(Cinnamomum verum) (88°C): Warm and spicy
• Ylang-Ylang(Cananga odorata) (78°C): Floral and exotic
• Petitgrain Bigarade(Citrus aurantium var. amara) (75°C): Fresh and subtly lemony
• Clary sage(Salvia sclarea) (85°C): Herbaceous with amber notes
• Peppermint(Mentha x piperita) (77°C): Refreshing and stimulating.

These essential oils can be used alone or combined to create unique blends, always ensuring that the estimated flash point of the blend remains above 65°C.

Tips for an optimal experience

To get the most out of your essential oil candles while minimizing risks:

1. First use: Burn long enough for the wax bath to reach the edges of the container (approx. 1 hour per 2.5 cm diameter).
2. Between uses: Cut the wick to about 5 mm before each lighting.
3. Supervision: Never leave a burning candle unattended.
4. Placement: Keep candles away from draughts, flammable materials and out of reach of children and pets.
5. Storage: Store your candles in a cool, dark place to preserve the properties of the essential oils.

Combine creativity and safety in your essential oil candles

At the end of this comprehensive guide, you'll have the essential knowledge to incorporate essential oils into your candles in a way that's both creative and safe. The technical challenges inherent in this practice should not discourage you, but rather encourage you to adopt a thoughtful, methodical approach.

What are the keys to success for your essential oil candles?

The success of your creations rests on three fundamental pillars:

1. Careful selection of essential oils: Choose essences with a flash point above 65°C, such as fine lavender(Lavandula angustifolia), patchouli(Pogostemon cablin) or ylang-ylang(Cananga odorata).
2. Technical mastery: scrupulously adhere to recommended incorporation temperatures and dosages.
3. Gradual experimentation: test your formulations on a small scale before embarking on larger-scale production.

Remember that every detail counts: the type of wax, the wick chosen, the incorporation temperature and the precise dosage of essential oils all contribute to the quality and safety of the final product.

Towards responsible, personalized practice

The art of creating candles with essential oils offers you the opportunity to design unique olfactory ambiences, in line with your personal preferences and the specific benefits you're looking for. This approach is perfectly in line with a wider trend towards handcrafted or homemade, natural and personalized products.

Whether you're creating these candles for your own personal use, as gifts, or even for commercial purposes, the balance between creativity and prudence will always be the key to a successful and fulfilling experience.

Feel free to consult the detailed appendices below to deepen your knowledge and gradually explore different essential oil combinations to develop your own olfactory signature. The world of essential oils for candles is vast and exciting - it's up to you to explore it safely!

 

Appendix 1: Comparison between Grasse perfumes and essential oils

Criteria	Grasse perfumes	Essential oils
Origin	Synthetic or semi-synthetic	100% natural (extracted from plants)
Thermal stability	Excellent - specifically formulated to withstand high temperatures	Variable - some essential oils degrade under heat
Fragrance diffusion	Constant and long-lasting throughout combustion	Often irregular, can fade rapidly
Olfactory palette	Very broad - can reproduce almost any scent	Limited to scents available in nature, but creativity can be expressed in blends
Flash point	Generally high (>90°C) - designed for candles	Variable (30-120°C) - requires careful selection
Olfactory intensity	Strong and constant at low concentrations (2-3%)	Often requires higher concentrations (5-6%)
Price	Generally more economical, especially for larger volumes	More expensive, especially for rare essential oils
Therapeutic benefits	None - designed solely for their fragrance	Potential aromatherapeutic effects depending on the essential oil
Environmental impact	Varies according to formulation (some are biodegradable)	Generally more ecological, but depends on extraction methods
Consistency between batches	Perfect - identical formulation for each production run	Variable - depends on plant growing conditions
Health risks	Low - tested for combustion safety	Potential risks for sensitive populations (allergies, irritations)
Compatibility with waxes	Excellent - formulations suitable for all types of waxes	Variable - may affect texture and combustion of some waxes

 

Appendix 2: Wax types and safety optimization

The choice of wax is decisive for compatibility with essential oils and the overall safety of your candle. Contrary to popular belief, the addition of vegetable oils is not recommended, as it can compromise the candle's combustion and stability.

Comparison of different waxes for essential oil candles

Type of wax	Melting temperature	Compatibility with HE	Advantages	Disadvantages
Soy wax	45-52°C	Excellent	- Lower melting point (safer) - Better fragrance diffusion - Biodegradable and renewable - Burns more slowly	- Fragrances do not hold up as well over time - May present visual irregularities
Beeswax	62-65°C	Good	- Natural and biodegradable - Natural, sweet, honey-like scent - Excellent fragrance retention - Air purification	- High cost - Higher melting point - Requires specific techniques
Rapeseed wax	42-48°C	Very good	- Very low melting point - Excellent diffusion of essential oils - Plant-based and biodegradable	- Limited availability - May be more brittle
Coconut wax	38-44°C	Excellent	- Lowest melting point - Ideal diffusion of essential oils - 100% vegetable and biodegradable	- Softer texture - May require stabilizers
Kerosene	55-65°C	Medium	- Good fragrance retention - Easy to use - Affordable cost - Stable texture	- Petrochemical, non-ecological - Higher melting point
Hybrid waxes (soy + kerosene)	50-58°C	Good	- Compromise between performance and naturalness - Better stability than pure soy	- Partially derived from petroleum

 

Strategies for optimizing the safety of essential oil candles

1. Choosing the right wax/essential oil combination

For essential oils with a low flash point (< 65°C), choose waxes with a low melting point:

• Coconut wax (38-44°C) is ideal for essential oils such as Eucalyptusglobulus or Citruslimon.
• Soy wax (45-52°C) is well suited to essential oils with a medium flash point, such as Tea tree(Melaleuca alternifolia).

2. Wax blending" technique

To simultaneously improve fragrance diffusion and safety, you can create customized blends:

• 80% soy wax + 20% beeswax: better fragrance hold with moderate melting point
• 90% coconut wax + 10% soy wax: excellent for essential oils with very low flash points

3. Double-casting method

Professional technique for integrating essential oils more safely:

1. First pour: pure wax without essential oils to form the base of the candle.
2. Second pour after partial cooling: blend of low-melting wax (coconut or soy) with essential oils

This method creates a double-layer candle in which the essential oils are incorporated into the outer layer at a lower temperature, considerably reducing the risks associated with flash point.

 

Appendix 3: Complete table of essential oils - Flash points, odors and effects

Essential oil	Latin name	Flash point (°C)	Olfactory profile	Generally recognized aromatherapeutic effects	Compatibility with candles
Patchouli	Pogostemon cablin	116°C	Woody, earthy, musky with sweet notes	Relaxing, balancing, aphrodisiac	Excellent - Very high flash point allowing a large safety margin
Clove	Eugenia caryophyllus	120°C	Spicy, warm, powerful	Stimulating, warming	Excellent - But use sparingly, as very powerful fragrance
Myrrh	Commiphora myrrha	>111°C	Warm, spicy, woody, slightly smoky	Soothing, meditative, spiritual	Excellent - Perfect for creating a meditative atmosphere
Cade Wood	Juniperus oxycedrus	110°C	Smoky, powerful, woody	Purifying, protective, soothing	Excellent - Ideal for neutralizing odors
Sweet ginger	Gaultheria fragrantissima	94°C	Menthole, fresh, medicinal	Refreshing	Very good - Persistent minty fragrance
Cinnamon (leaves)	Cinnamomum verum	94°C	Spicy, warm, sweeter than bark	Stimulating, warming, invigorating	Very good - Ideal for winter candles
Cinnamon (bark)	Cinnamomum verum	88°C	Spicy, warm, sweet	Stimulating, warming, energizing	Very good - Perfect for autumn/winter ambience
Ylang-Ylang	Cananga odorata	78°C	Floral, exotic, sweet	Relaxing, aphrodisiac, balancing	Very good - Creates a sensual atmosphere
Peppermint	Mentha x piperita	77°C	Minty, fresh, penetrating	Stimulating, refreshing, brightening	Good - pronounced refreshing effect
Lavender stoechade	Lavandula stoechas	76°C	Floral, herbaceous, more camphoraceous than fine lavender	Relaxing, purifying, balancing	Good - Alternative to fine lavender
Exotic verbena	Litsea cubeba	76°C	Lemony, fresh, green	Soothing, refreshing, anti-stress	Good - Long-lasting lemon fragrance
Bitter orange petitgrain	Citrus aurantium	75°C	Floral, fresh, slightly bitter	Soothing, balancing, anti-stress	Good - Fresh, elegant fragrance
Tropical basil	Ocimum basilicum	75°C	Aniseed, fresh, herbaceous	Mental stimulant, clarifying, tonic	Good - Use sparingly (strong fragrance)
Fine Lavender	Lavandula angustifolia	71°C	Floral, herbaceous, soft	Relaxing, soothing, balancing	Good - The benchmark for relaxing candles
Tarragon	Artemisia dracunculus	70°C	Aniseed, herbaceous, fresh	Calming, balancing	Good - Subtle, original fragrance
Fragrant Verbena	Lippia citriodora	69°C	Lemony, fresh, herbaceous	Calming, anti-stress	Medium to good - Delicate lemony fragrance
Ginger	Zingiber officinale	65°C	Spicy, warm, lemony	Stimulating, tonic, warming	Medium - Just at the recommended threshold
Lavandin super	Lavandula x intermedia	65°C	Floral, camphorated, fresher than lavender	Purifying, toning, balancing	Medium - More affordable than fine lavender
Rose Geranium	Pelargonium graveolens	64°C	Floral, pink, fresh	Balancing, soothing, invigorating	Medium/Risked - Slightly below ideal threshold
Mountain savory	Satureja montana	63°C	Herbaceous, spicy, penetrating	Stimulating, invigorating, warming	Risky - Below recommended threshold, to mix
Spearmint	Mentha spicata	63°C	Minty, fresh, herbaceous	Invigorating, refreshing, stimulating	Risky - Flash point limit, mix
Sweet fennel	Foeniculum vulgare	63°C	Aniseed, mild, herbaceous	Balancing, soothing	Risky - To mix
Wild oregano	Origanum vulgare	62°C	Herbaceous, spicy, powerful	Stimulating, purifying, tonic	Risky - Avoid or mix
Thyme thujanol	Thymus vulgaris ct. thujanol	60°C	Herbaceous, mild, less aggressive than classic thyme	Immunostimulant, purifying	Not recommended - Insufficient flash point
Marjoram	Origanum majorana	59°C	Herbaceous, mild, slightly camphorated	Calming	Not recommended - Too risky
Bergamot	Citrus bergamia	59°C	Citrus, fresh, slightly floral	Refreshing	Not recommended - Flash point too low
Neroli	Citrus aurantium	59°C	Floral, delicate, slightly lemony	Soothing, anti-stress, regenerating	Not recommended - better suited to cold diffusion
Tea tree	Melaleuca alternifolia	58°C	Medicinal, fresh, herbaceous	Purifying, immunostimulant	Not recommended - Insufficient flash point
Lavender aspic	Lavandula latifolia	57°C	Camphorated, more medicinal than fine lavender	Soothing, purifying	Not recommended - Flash point too low
Borneol thyme	Thymus vulgaris ct. borneol	57°C	Herbaceous, less aggressive than classic thyme	Immunostimulant, balancing	Not recommended - Risk of inflammation
Coriander	Coriandrum sativum	56°C	Spicy, warm, slightly citrusy	Invigorating, stimulating	Strongly not recommended - Flash point too low
Thyme linalool	Thymus vulgaris ct. linalool	55°C	Herbaceous, sweet, floral	Balancing, mild stimulant	Strongly not recommended - Insufficient flash point
Carrot	Daucus carota	54°C	Earthy, sweet, slightly woody	Invigorating	Not recommended - Risk of inflammation
Damask Rose	Rosa damascena	54°C	Floral, rich, deep	Harmonizing, soothing, regenerating	Not recommended - Very expensive and low flash point
Lemon	Citrus limon	53°C	Citrus, fresh, sparkling	Toning, purifying, stimulating	Not recommended - Dangerous flash point
Niaouli	Melaleuca quinquenervia	53°C	Camphorated, fresh, medicinal	Immunostimulant, purifying	Strongly not recommended - High risk
Roman chamomile	Anthemis nobilis	52°C	Fruity, apple, herbaceous	Calming	Strongly not recommended - Insufficient flash point
Eucalyptus radiata	Eucalyptus radiata	51°C	Fresh, camphorated, medicinal	Respiratory, purifying, refreshing	Strongly not recommended - High risk
Ravintsara	Cinnamomum camphora	50°C	Camphorated, eucalyptus, mild	Antiviral, immunostimulant	Strongly not recommended - Dangerous flash point
Parsley	Petroselinum crispum	50°C	Green, herbaceous, fresh	Invigorating	Strongly inadvisable - High risk
Mandarin	Citrus reticulata	49°C	Citrus, mild, sweet	Calming, relaxing	Absolutely avoid - High risk of inflammation
Sweet orange	Citrus sinensis	48°C	Citrus, sweet, fresh	Soothing, relaxing, anti-stress	Absolutely avoid - Very low flash point
Laurier noble	Laurus nobilis	48°C	Spicy, aromatic, slightly fruity	Invigorating, stimulating, purifying	Absolutely avoid - Insufficient flash point
Black spruce	Picea mariana	46°C	Woody, fresh, balsamic	Invigorating, respiratory, energizing	Absolutely avoid - Flash point too low
Saro	Cinnamosma fragrans	45°C	Fresh, camphorated, mild eucalyptus	Antiviral, immuno-stimulant, respiratory	Absolutely avoid - Dangerous flash point
Grapefruit	Citrus paradisi	44°C	Citrus, fresh, slightly bitter	Stimulating, invigorating	Absolutely avoid - Very low flash point
Eucalyptus globulus	Eucalyptus globulus	44°C	Camphorated, fresh, medicinal	Respiratory, purifying, stimulating	Absolutely avoid - Insufficient flash point
Galbanum	Ferula galbaniflua	43°C	Green, earthy, resinous	Soothing	Absolutely avoid - Dangerous flash point
Black pepper	Piper nigrum	43°C	Spicy, hot, pungent	Invigorating, stimulating, warming	Absolutely avoid - High risk
Rosemary cineole	Rosmarinus officinalis	43°C	Herbaceous, camphorated, fresh	Stimulating, invigorating, energizing	Absolutely avoid - Flash point too low
Angelica (root)	Angelica archangelica	43°C	Earthy, musky, spicy	Balancing, invigorating	Absolutely avoid - Risk of inflammation
Hemlock	Tsuga canadensis	42°C	Woody, balsamic, sweet	Soothing, balancing, respiratory	Absolutely avoid - Insufficient flash point
Balsam fir	Abies balsamea	42°C	Woody, resinous, fresh	Respiratory, soothing, purifying	Absolutely avoid - High risk
Frankincense	Boswellia carterii	41°C	Woody, resinous, slightly lemony	Meditative, spiritual, soothing	Extremely low flash point
Juniper berry	Juniperus communis	41°C	Woody, resinous, spicy	Purifying, invigorating	Absolutely avoid - Dangerous flash point
Scots pine	Pinus sylvestris	40°C	Softwood, fresh, woody	Respiratory, invigorating, purifying	Absolutely avoid - Very high risk of inflammation
Nutmeg	Myristica fragrans	38°C	Spicy, woody, warm	Invigorating, stimulating, warming	Absolutely avoid - Dangerous flash point
Myrtle	Myrtus communis	36°C	Fresh, herbaceous, slightly camphorated	Respiratory, balancing, purifying	Absolutely avoid - Extremely low flash point
Cypress	Cupressus sempervirens	35°C	Softwood, woody, fresh	Respiratory, invigorating	Absolutely avoid - Dangerous flash point
Pistachio mastic	Pistacia lentiscus	33°C	Resinous, woody, earthy	Invigorating	Extremely low flash point
White fir	Abies alba	32°C	Woody, resinous, fresh	Respiratory, purifying, invigorating	Absolutely avoid - Lowest flash point of all EOs, maximum risk