The following information contains excerpts from my books, Healing with Essential Oils, Essential Oils for the Whole Body and Essential Oils for Mindfulness and Meditation(published by Healing Arts Press, Vermont USA)

Guidelines

Measurement percentages can seem quite complicated, especially considering that dropper top sizes vary, and that some oils are more viscose than others, which renders absolute accuracy of measurement impossible; the quantity of essential oil released per drop varies. However, in the interest of safety, essential oil quantities do need careful consideration. As a ‘rule of thumb guide’, the measurements set out in the guide below are based on average droplet sizes.

Risk of sensitivity or irritation reactions increase where large amounts of essential oil are applied to very small areas of skin – applying 6 drops of essential oil in a carrier medium applied to the whole body through massage will have negligible irritant effect, yet the same quantity of essential oil applied to a small area of skin can be irritant, particularly in sensitive areas such as the face, or under arms if used as deodorants, and so on.  If you do experience any skin or respiratory tract irritation (itching, redness, rashes, swelling, breathing difficulty) stop applying the essential oil or the blend of essential oils immediately.

Remember, use essential oils within their stipulated use-by date (found on the bottle or packaging).  For further safety details please refer to Safe Use and Application and Essential Oils: Keeping the lid on.

Use no more than 1 or 2 drops of essential oils in a carrier medium on localised areas of skin. Keep this in mind when making first aid ointments or face creams or lotions. When making face creams or ointments for repeated regular use, make up small quantities that can be used up quickly and frequently refreshed; reduce the amount of essential oils included; change the essential oil selection and/or blend from time to time; and have ‘no essential oil’ breaks in between use.

You will find deeper detail about essential oils and their appropriate use and application in my books, Essential Oils for Mindfulness and Meditation, and Essential Oils for the Whole Body (available from most bookshops and online stores)

Safe Measurements

A 5ml bottle of essential oil contains approximately 100 drops of essential oil

A 10ml bottle of essential oils contains approximately 200 drops of essential oil

• Maximum amount of essential oil per 24 hour period = 6 to 10 drops (healthy adult – see below)
• Apply for 2 to 3 weeks only, followed by 1 week’s abstinence, and change essential oil(s) selection regularly

Carrier Medium = vegetable oils, non-perfumed creams, lotions, ointments and gels

• 1 drop of essential oil in 5 ml of carrier medium = 1% blend
• 2 ½ drops of essential oil in 5 ml of carrier medium = 2.5% blend (round up or down – 2 0r 3 drops)
• 5 drops of essential oil in 5 ml of carrier medium = 5% blend

Appropriate quantities

Reduced amount for children and babies over 3 months old (see above recommendations regarding infants), and those with sensitivities.

Use maximum dilution (1 drop of essential oil in 20ml vegetable oil or non-perfumed cream or lotion) for babies between 3 months and 24 months old, do not use herbaceous, spicy, citrus oils, highly perfumed oils, or citrus-like oils such as lemongrass or citronella (see Safe Use and Application), and always ensure the genuine purity of your essential oil before applying – 100% pure unadulterated essential oil purchased from a reputable supplier who provides relevant safety information (please note, I do not advocate the use of essential oils for infants under three years old, but include advise here to ensure safety).  Also use increased dilution for those who are frail or very elderly and those with sensitivities, allergies, eczema, asthma, and for facial blends.

• 1 drop of essential oil in 5 ml of carrier medium = 1% blend
• 2 drops of essential oil in 10 ml of carrier medium = 1% blend

• 1 drop of essential oil in 10 ml of carrier medium = 0.5% blend
• 2 drops of essential oil in 20 ml of carrier medium = 0.5% blend

• 1 drop of essential oil in 20ml of carrier medium = 0.25% blend (babies and toddlers 3 months to 24 months – do not use herbaceous, spicy or citrus oils)

Normal amount for general and adult use

• 2 ½ drops of essential oil in 5 ml of carrier medium = 2.5% blend (rounded up of down)
• 5 drops of essential oil in 10 ml of carrier medium = 2.5% blend

Acute / exceptional amount for acute, short-term occasional use. Avoid or reduce the use of known irritant essential oils.

• 5 drops of essential oil in 5 ml of carrier medium = 5%
• 10 drops of essential oil in 10 ml carrier medium = 5% blend

For further information about measuring essential oils, and their safe and effective use, please refer to my books:

Healing with Essential Oils

Essential Oils for the Whole Body

Essential oils for Mindfulness and Meditation