Part 3 Candle Fragrances: Making Sense of Scents

What about the fragrances used in candles to give them their scent?  Are they safe?

Historically, the fragrance industry has never been transparent about safety. Lack of disclosure from fragrance manufacturers regarding ingredients and the possible health risks of those ingredients that make up perfumes, colognes and other scented products like candles was the norm. However, in recent years, consumers have pushed for more information about the ingredients that make up scents.

The safety of inhaling a fragrance during candle burning is influenced by:

  1. Chemical Composition: The specific chemicals used in the fragrance oil can affect its safety when burned. Some chemicals, even in small quantities, can be irritating or harmful when inhaled.
  2. Concentration: The concentration of the fragrance oil in the candle can impact the intensity of the scent and the potential for irritation. High concentrations of fragrance oil may result in a more potent scent but could also increase the likelihood of irritation.
  3. Ventilation: Proper ventilation can help disperse the fragrance and reduce the concentration of airborne particles, potentially minimizing the risk of respiratory irritation.
  4. Individual Sensitivity: People vary in their sensitivity to fragrance compounds, and what may be safe for one person may cause discomfort or allergies in another.

In candle making, there are three main categories of fragrances:

  1. Synthetic fragrances: Many scented candles use synthetic fragrances for their wide variety of scents and affordability. However, synthetic fragrances can release chemicals which have been associated with hormone disruption and other health issues.
  2. Natural essential oils: In today’s market, many candles are scented with natural essential oils, such as lavender or eucalyptus. These options are often preferred by those seeking a more natural and potentially safer alternative. However, there are some aspects of essential oils that need to be considered.
  3. Blended scents: Some candles combine both synthetic and natural fragrances to achieve unique scents while attempting to mitigate health concerns.

Synthetic Fragrances

The synthetic fragrances that are used in making candle scents usually contain phthalates.  Phthalates are a family of man-made chemical compounds developed in the last century to be used in the manufacture of plastics, solvents, and personal care products. They are colorless, odorless, oily liquids that do not evaporate easily and do not chemically bind to the material they are added to. They are often added to plastics to make them more pliable.

The use of phthalates in consumer products is linked to a wide range of negative health effects including hormone disruption, low birth weight in babies, organ damage, conduct disorders in children, and more.

Due to these concerns, some phthalates have been banned or restricted in various countries for use in certain products, especially those intended for children. In the United States, the Consumer Product Safety Improvement Act (CPSIA) restricts the use of certain phthalates in children’s toys and childcare articles.

As a precautionary measure, many manufacturers have also moved towards using alternative plasticizers in other products, including some that are labeled as “phthalate-free” to assure consumers that they do not contain these chemicals.

It’s important to note that the potential risks associated with phthalate exposure can depend on the specific type of phthalate, the level of exposure, and individual susceptibility. Researchers continue to study the effects of phthalates on human health, and regulatory agencies monitor and assess the risks to protect public health and safety.

In candle manufacturing, phthalates can be added during the production process to make the wax more pliable and/or to help fragrances disperse more evenly by helping bind the fragrance to the wax.

When phthalates are present in candle wax, they may be released into the air when the candle is burned. The exact amount of phthalates released can depend on various factors, including the type of phthalates used, the candle’s composition, and how the candle is burned. The phthalates that are released into the air can be inhaled or absorbed through the skin. When the phthalates enter the bloodstream, they can exacerbate allergic symptoms and asthma and alter hormone levels.

While some studies have detected the presence of phthalates in the emissions from certain types of candles, it’s important to note that the levels of phthalates released from candle burning are generally considered to be low and are not likely to pose a significant health risk to most individuals. The concern over phthalates typically centers on long-term exposure to higher concentrations of these chemicals, such as through personal care products, plastics, or occupational settings.

If you are concerned about the potential presence of phthalates in candles, you can look for candles labeled as “phthalate-free” or made from natural waxes, such as beeswax or soy wax, which do not typically contain phthalates. But since fragrances may also introduce phthalates into the mix, this possibility should be considered.

Proper ventilation and safe candle use practices can help reduce exposure to any potential emissions from candles, including those containing phthalates.

However, as I noted earlier, following that advice may run counter to the way many people use scented candles: to scent a volume of air in rooms that are not being ventilated.

Beyond phthalates, a variety of chemicals used in  synthetic fragrances have been associated with health issues. While the exact composition of synthetic fragrances is often considered proprietary and not disclosed by manufacturers, research has shown that some of these fragrances can emit volatile organic compounds (VOCs) when burned, which can have health implications. Here are a few other chemicals commonly found in synthetic fragrances that have raised concerns:

  1. Volatile Organic Compounds (VOCs): Synthetic fragrances can release VOCs when burned, and some of these compounds, such as benzene and formaldehyde, are known to be harmful to human health. Prolonged exposure to high levels of VOCs can lead to respiratory issues and other health problems.(Pthalates are considered semi-VOCs or SVOCs)
  2. Aldehydes: Some synthetic fragrances contain aldehydes, which can be irritants and allergens for some individuals. Aldehydes like cinnamaldehyde and benzaldehyde have been associated with skin and respiratory irritation.
  3. Acetone: Acetone is a common solvent used in the manufacture of synthetic fragrances. It has a strong odor and can cause eye, nose, and throat irritation when inhaled in high concentrations.
  4. Limonene and Linalool: These natural compounds are often used to mimic citrus and floral scents in synthetic fragrances. While they are derived from natural sources, they can also react with ozone in indoor air to produce formaldehyde, a known irritant and potential carcinogen.
  5. Musk Compounds: Some synthetic fragrances contain synthetic musk compounds like nitromusks and polycyclic musks. These chemicals have been found to accumulate in the body and have raised concerns about potential long-term health effects.
  6. Allergens: Synthetic fragrances can contain allergenic compounds that may cause skin sensitization or allergic reactions in susceptible individuals. These reactions can range from mild skin irritation to more severe dermatological issues.

It is important to note that the items listed above don’t always pose a risk at the concentrations used in fragrance or essential oil, they’ve simply been flagged as potentially toxic or hazardous in large quantities or as raw materials.

Health effects of exposure to these chemicals can vary depending on the concentration, duration, and individual sensitivity. Some people may be more sensitive to synthetic fragrances than others. If you’re concerned about potential health risks associated with synthetic fragrances in candles, consider candles labeled as “fragrance-free” or “hypoallergenic” if you have sensitivities or allergies. Candles that are “VOC-free” are another option.  Proper ventilation can also help reduce the concentration of airborne chemicals when burning scented candles indoors.

If your candle maker is using synthetic fragrances, see how/if they are addressing potential issues.

Essential Oils

Given all the concerns laid out so far, should you just buy candles that use essential oils such as lavender or eucalyptus, to provide scent?  These options may be preferred by those seeking a more natural and potentially safer alternative. But there are issues to consider. Some essential oils can release compounds that may be toxic or irritating when burned in scented candles, particularly when they are used in excessive amounts or not handled correctly. It’s important to use caution when using candles or other products containing essential oils, especially if you or others in your household have a history of skin sensitivities, allergies, or respiratory issues.


Certain essential oils contain compounds that can be toxic when inhaled in large quantities.

  1. Wintergreen oil: Wintergreen oil contains methyl salicylate, which can be toxic in high concentrations and may cause respiratory issues.
  2. Eucalyptus oil: Eucalyptus oil contains a compound called eucalyptol. While eucalyptol is generally considered safe when used in appropriate concentrations, high doses can be toxic. Eucalyptus essential oil is commonly used for its clearing and decongestant properties. However, the eucalyptol it contains can trigger respiratory discomfort or allergies in some individuals.
  3. Camphor oil: Inhaling the vapors of camphor oil, especially in large amounts, can lead to nausea, headache, and respiratory irritation.
  4. Pennyroyal oil: Pennyroyal oil contains pulegone, which can be toxic, especially in large quantities. It may cause nausea, vomiting, and other adverse effects.
  5. Sage oil: Sage oil contains thujone, which can be neurotoxic in high doses. Prolonged exposure to thujone may be harmful.
  6. Wormwood oil: Like sage oil, wormwood oil contains thujone and should be used with caution due to its potential neurotoxic effects.

Someone making candles should always ensure proper dilution and follow safety guidelines when working with essential oils in candle making to minimize the risk of adverse reactions. If you have concerns about allergies or sensitivities, consider using essential oil blends that are known to be gentle or seek advice from a healthcare professional.

Irritation and Allergies

Certain essential oils, even when diluted, can cause irritation or allergic reactions in some individuals when released into the air during candle burning. People with respiratory sensitivities or allergies should be cautious when using or purchasing candles with strong essential oil scents.

Phenol compounds

Phenols are a class of aromatic compounds that are found in various essential oils. Essential oils containing high levels of phenol compounds are known for their antimicrobial, antiviral, and antioxidant properties. However, it’s important to use them in moderation and with caution, as some phenolic essential oils can be irritating to the skin and mucous membranes or even toxic when inhaled in large quantities.

Here are some essential oils that are high in phenol compounds:

Thyme oil: Thyme essential oil is rich in phenols, particularly thymol. Thymol is known for its strong antimicrobial properties.

Oregano oil: Oregano essential oil contains phenolic compounds such as carvacrol and thymol, contributing to its antimicrobial activity.

Clove oil: Clove essential oil is high in eugenol, a phenolic compound with potent antimicrobial properties. However, eugenol can be irritating and should be used in moderation.

Cinnamon bark oil: Cinnamon bark essential oil contains cinnamaldehyde, a phenolic compound known for its antimicrobial and antioxidant properties.

Basil oil: Basil essential oil contains phenols, including methyl chavicol and linalool, which contribute to its antibacterial and antifungal properties.

Peppermint oil: Peppermint essential oil contains phenolic compounds such as menthol and menthone. While not as high in phenols as some other oils, peppermint oil still possesses antimicrobial properties.

Tea tree oil: Tea tree essential oil, derived from the Australian tea tree (Melaleuca alternifolia), contains phenolic compounds like terpinen-4-ol, known for its antimicrobial properties.

Rosemary oil: Rosemary essential oil contains phenolic compounds, including rosmarinic acid, with antioxidant and anti-inflammatory properties.

Topical reactions

When essential oils are used in candles, there is a potential risk of skin reactions if the oil is deposited on the skin, particularly if the candle wax is spilled or if the person comes into direct contact with the oil during candle maintenance.

Citrus oils: Essential oils from citrus fruits like lemon, lime, bergamot and grapefruit are generally safe, but they can be photosensitizing when applied to the skin and may cause skin irritation in some people.


Essential oils should not be ingested, and these oils (below) are especially dangerous. Candles scented with these oils should be kept out of reach of children and pets.

Wintergreen oil

Eucalyptus oil

Clove oil

Tea tree oil

Cinnamon oil

Pennyroyal oil

Camphor oil

Sage oil

Fire Hazard

Some essential oils have low flashpoints, which means they can ignite at relatively low temperatures. If not properly handled and added to the candle wax at safe concentrations, they could pose a fire hazard during candle production or use.

Flashpoints can vary depending on factors such as the specific chemical composition of the oil and the presence of impurities. Using caution when working with essential oils, especially those with lower flashpoints, is crucial to ensure safety. Here are some essential oils that are known to have relatively low flashpoints:

  1. Citrus oils: Essential oils derived from citrus fruits, such as lemon (Citrus limon), orange (Citrus sinensis), and grapefruit (Citrus paradisi), tend to have lower flashpoints. For example, lemon oil has a flashpoint around 115°F (46°C).
  2. Pine oil: Pine essential oil, extracted from pine trees, can have a flashpoint around 95°F (35°C).
  3. Cypress oil: Cypress essential oil may have a flashpoint around 131°F (55°C).
  4. Spruce oil: Spruce essential oil, derived from various species of spruce trees, can have a flashpoint around 109°F (43°C).
  5. Juniper berry oil: Juniper berry essential oil may have a flashpoint around 92°F (33°C).

When using essential oils, it’s essential to dilute them properly and follow recommended guidelines. Additionally, individuals with sensitive skin or certain health conditions should exercise caution and may want to consult with a healthcare professional before using these oils.

To mitigate these risks, responsible candle makers who use essential oils take several precautions:

  • They carefully measure and dilute essential oils to safe concentrations, adhering to industry standards and safety guidelines.
  • They conduct safety testing to ensure that the candles emit scents safely when burned.
  • They provide clear labeling on candles to indicate which essential oils are used, allowing consumers to make informed choices.
  • They offer guidelines for safe candle usage, including burning in well-ventilated areas and keeping candles away from children and pets.

Essential Oils and Stability

Beyond health and safety considerations, there are effectiveness issues to consider.  Essential oils are sometimes less stable in use. Certain essential oils are more prone to evaporation when exposed to heat. Citrus oils, like lemon, orange, and grapefruit, are known for their volatility and may dissipate more quickly during burning. Other delicate essential oils, such as lavender and eucalyptus, can also be sensitive to heat. On the flip side, some oils with heavier molecules, like patchouli or cedarwood, tend to hold up better in the heat and may maintain their scent for a longer duration. If you have specific concerns or questions about the use of essential oils in scented candles, contact the candle maker or manufacturer for information about their safety practices and the specific oils used in their products. Ask if the scent of the candle is liable to be maintained over time, both when the candle is unlit and when the candle is burning. Additionally, if you have known sensitivities or allergies to certain essential oils, you should carefully read the candle’s ingredients and consider candles with scents that are less likely to trigger reactions. Essential oils and fragrance oils are not considered unsafe or dangerous when used as intended. Used correctly, they should not pose a risk at the concentrations used in fragrance or essential oil, they’ve simply been flagged here as potentially toxic or hazardous in large quantities or as raw materials. Or as potential triggers in individuals with sensitivities or allergies.

What about ‘Skin safe” fragrances?

The designation “skin safe” for a candle fragrance indicates that the fragrance oil has been formulated or tested to be less likely to cause skin irritation or sensitization when applied to the skin in its undiluted form. However, this designation primarily relates to the safety of the fragrance when it comes into direct contact with the skin and does not necessarily provide information about the safety of inhaling the fragrance as a candle burns. Inhaling a fragrance from a candle involves a different mode of exposure compared to applying it to the skin. When a candle is burned, the fragrance compounds are vaporized and released into the air. As noted above, whether a fragrance is safe to inhale while burning depends on various factors, including the specific chemicals in the fragrance, their concentrations, and individual sensitivities.Even if a fragrance is labeled as “skin safe,” it may still contain volatile organic compounds (VOCs) or other chemicals that could potentially irritate the respiratory system or cause allergic reactions in some individuals when inhaled.To determine whether a specific candle fragrance is safe to inhale when burned, it’s essential to consider the ingredients listed on the candle’s label, conduct research on the manufacturer’s safety testing practices, and take into account your own sensitivities and preferences. If you have concerns about the safety of a particular candle fragrance or have a history of respiratory issues or allergies, choose candles with those concerns in mind, and ensure good ventilation when burning candles indoors.

Brimstone Candle Company and Candle Fragrances

Brimstone Candle Company is dedicated to offering only candles that are safe. As of the writing of this blog post, 100% of the dyes and fragrances are skin-safe.  Close to 80% of the fragrances used in the candles are VOC free. When the transition is completed (in 2024), 100% of Brimstone candle fragrances will be VOC-free.

Next & Final Part in the series: Candles in colors. Are candle dyes safe?

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