Essential oil safety

01The four rules

If you remember nothing else on this page, remember these.

1. Essential oils are not to be taken. Not a drop, not in water, not in a capsule, not in honey.
2. They are extremely concentrated. A single drop can be the distilled essence of a great deal of plant material. Treat a 10 mL bottle as you would treat a strong chemical, not as you would treat a food.
3. Keep them out of reach of children. The bottles are small, they smell pleasant, and the dropper insert is not a child-resistant closure.
4. Never apply them undiluted to skin. Even the gentlest oils. See Skin below.

02Swallowing

Essential oils are for aromatic use. They are not food-grade flavourings, they are not supplements, and they are not to be swallowed — regardless of what you may read elsewhere.

A small quantity can cause serious harm, particularly to a child. Eucalyptus oil in particular is a well-known cause of accidental poisoning in Australian households, precisely because it is common, pleasant-smelling and often left within reach.

03Skin

We do not recommend our essential oils for skincare. That is a positioning decision, not a moral one — and it does not make the subject go away, because people will use them on skin regardless. So here is the whole picture.

Why undiluted is the problem

An essential oil is not a diluted plant extract. It is the volatile fraction of the plant, separated and concentrated, often by a factor of many hundreds. What is harmless in a leaf can be an irritant in a bottle.

Applied neat, the common outcomes are redness, stinging, and a burning sensation that can persist for hours. The less common outcome is sensitisation — a permanent immune response to that oil, and often to related ones. Sensitisation does not wear off. Once you have it, you have it for life, and it is usually the result of repeated neat application rather than a single exposure.

Dilution

Essential oils do not dissolve in water. They dissolve in fats and oils. To dilute one, you use a carrier — jojoba, sweet almond, apricot kernel, grapeseed, or an unscented cream.

For an adult, one or two drops in 5 mL of carrier is a usual strength. Less for sensitive skin, and less again for children. Stronger than that raises the chance of a reaction without adding anything.

Patch testing

Before using any oil on skin for the first time, dilute it to the strength you intend to use, apply a small amount to the inner forearm, cover it, and leave it for 24 hours. If there is any redness, itching or swelling, do not use that oil. A reaction that appears after several hours rather than immediately is the more significant one — that is an allergic response rather than simple irritation.

Oils that need more care than most

Some oils are known irritants or sensitisers even when diluted. In our range, treat these with particular caution:

CinnamonLemongrassMay ChangClove BudThymeGingerBlack PepperNutmegPeppermint

Cinnamon bark oil in particular is a strong sensitiser and should not be applied to skin at all.

04Sunlight

Some citrus oils contain furocoumarins — bergapten and its relatives — which react with ultraviolet light. On skin that has been exposed to these compounds, sunlight can produce a burn or a lasting dark patch at doses that would otherwise be harmless. The effect can appear hours later, and the discolouration can take months to fade.

This depends on how the oil was made. Furocoumarins are heavy molecules: they carry over when a citrus peel is cold pressed, and they are left behind when the same peel is steam distilled. A distilled lime oil is not phototoxic; an expressed one is.

Springfields essential oils are steam distilled unless the label specifically states otherwise. Where a label does say cold pressed — Bergamot is the one to note — assume the oil is phototoxic and keep it off skin that will see sunlight for at least twelve hours.

05Eyes

Keep essential oils away from the eyes, and wash your hands after handling a bottle before touching your face. Menthol- and cineole-rich oils — peppermint, eucalyptus, spearmint — can sting the eyes from the vapour alone.

06Children

The specific concern with peppermint, eucalyptus and rosemary in young children is respiratory. Menthol and 1,8-cineole can cause a reflex slowing of breathing in small children when applied to or inhaled near the face. This is why these oils are kept away from the chest, neck and face of anyone under six.

Store bottles where a child cannot reach or see them. A dropper insert slows a child down; it does not stop one.

07Pregnancy and breastfeeding

There is no settled consensus here, and reasonable practitioners disagree. What is generally agreed is that the first trimester warrants the most caution, and that diffusing at low concentration in a ventilated room is a different proposition from applying oils to skin.

Oils commonly avoided during pregnancy include:

Clary SageSageRosemaryJuniperAniseedFennelBasilMarjoramMyrrhCinnamonNutmegThymeCypressCarrot Seed

This list is not exhaustive and is not a substitute for advice. If you are pregnant, trying to conceive, or breastfeeding, speak to your midwife, doctor or a qualified aromatherapist before using essential oils.

08Asthma and respiratory conditions

Strong aromas can trigger bronchospasm in some people with asthma, and the oils most often reached for when someone feels congested — eucalyptus, peppermint, tea tree — are among the more likely to do so.

If you or anyone in the household has asthma, chronic obstructive pulmonary disease, or any other respiratory condition, introduce any new oil cautiously, diffuse at low concentration in a ventilated room, and stop at the first sign of tightness or wheeze. Speak to your doctor first.

The same applies to anyone with epilepsy: rosemary, sage, fennel and hyssop are conventionally avoided.

09Pets

This is the part most people have not been told, and it matters more than most of the rest.

Cats

Cats lack an enzyme — glucuronyl transferase — that most mammals use to clear phenols and monoterpenes from the body. Compounds that a person metabolises in hours can accumulate in a cat. Symptoms of exposure include drooling, unsteadiness, tremors, vomiting and lethargy, and they can appear after repeated small exposures rather than one large one.

Never apply any essential oil to a cat, and never leave a cat in a room with a running diffuser and no way out. Tea tree is the most dangerous of the common oils; citrus, pine, peppermint, eucalyptus, wintergreen and ylang ylang all warrant the same caution.

Dogs

Dogs tolerate aromatic compounds better than cats, but tolerate is not the same as benefit. Do not apply essential oils to a dog's coat or skin. When diffusing, leave the door open so the animal can leave the room — a dog's sense of smell is many times more acute than yours, and what reads as pleasant to you may be overwhelming.

Birds

Do not diffuse essential oils in a room with a bird. Birds have an exceptionally efficient respiratory system with no capacity to tolerate airborne irritants, and reactions can be sudden and fatal.

10Diffusing

• Four to six drops in an ultrasonic diffuser is enough for an ordinary room. More is not better — beyond a certain point, the nose stops registering the difference and only the exposure increases.
• Diffuse for thirty to sixty minutes at a time, not continuously. Intermittent diffusion is both more effective and safer; a continuously running diffuser mostly produces a room in which nobody can smell anything.
• Ventilate. A closed room with a running diffuser is a different exposure from an open one.
• Do not diffuse in a room where an infant, a cat or a bird cannot leave.
• Empty and clean the diffuser between oils. Residue oxidises and the next session will not smell the way it should.
• Never put essential oil into the flame or the melted wax of a candle. It is flammable.

11Baths

This is the most commonly mishandled use, and the reason is simple physics: oil does not dissolve in water.

Drops added straight to a bath do not disperse. They float, coalesce into a film, and make contact with skin at full strength — which is to say, the bath delivers exactly the undiluted application that every other part of this page tells you to avoid, and delivers it to the most sensitive areas of the body.

Always mix the oil into a dispersant first — a purpose-made aromatherapy dispersant, or failing that full-cream milk, cream, or a tablespoon of a carrier oil. Six drops of essential oil to six drops of dispersant, stirred into the water, is a reasonable starting point for an adult.

12Storage and shelf life

Essential oils are degraded by heat, light and oxygen. Store them below 30 °C, out of direct sunlight, with the caps firmly on. The amber glass is not decoration — it is there to keep light out.

An oxidised oil is not merely a weaker oil. Oxidation products are a common cause of skin reactions, and an old citrus oil is considerably more likely to irritate than a fresh one.

If an oil smells sharp, flat or faintly of turpentine where it once smelled of the plant, it has oxidised. Use it in a diffuser if you like, but not on skin.

13Fire, spills and surfaces

Flammability

Essential oils are flammable. Keep them away from open flame, hotplates and heaters. Do not add them to a lit candle. Cloths soaked in essential oil should be laid flat to dry rather than bundled into a bin.

Surfaces

Undiluted essential oils dissolve polystyrene, soften some plastics, and lift varnish, wax and paint. Citrus and peppermint oils are the worst offenders. Use glass, ceramic or stainless steel for blending, and wipe spills off timber and painted surfaces immediately.

Disposal

Do not pour essential oils down the sink or into stormwater. Small household quantities can be absorbed onto paper and placed in general waste; larger quantities should go to a household chemical collection.

14Notes on our own range