Contents:

1. What are Essential Oils?
   1. What are Different Grades of Essential Oils?
   2. How are Essential Oils Made?
   3. How are Absolutes Made?
2. How to Use Essential Oils?
   1. Topical Application: Using Essential Oils on the Skin and Hair
      1. What are the Best Essential Oils for Skincare?
      2. What are the Best Essential Oils for Haircare?
      3. What are Non-cosmetic Topical Applications of Essential Oils?
   2. Aromatherapy: Using the Aroma of Essential Oils for Wellness 
      1. How to Use Essential Oils in Aromatherapy
   3. Oral Administration
3. How to Make Essential Oil Blends / How to Blend Essential Oils?
   
4. Shelf Life and Expiration of Essential Oils
   

1. What are Essential Oils?

An essential oil is a natural, concentrated aromatic extract derived from plant material, typically obtained through steam distillation or cold pressing, that captures the characteristic essence of the plant, including properties valued in traditional and aromatherapy practices.

As the extracted oil captures the characteristic essence of the plant, the end product is referred to as the essential oil, the oil that carries the plant’s essence.

1.1. What are Different Grades of Essential Oils? 

Essential oils are categorised into different grades, depending on their purity and intended use, 

• Therapeutic Grade: 100% Pure, unadulterated essential oils meant for aromatherapy and topical application.
  
  
• Food Grade: Safe for flavouring food; must meet food safety standards and specifically be certified and refined for consumption. 
  
  
• Cosmetic Grade: Often diluted with carrier oils or synthetic additives. Suitable for topical application and beauty products. 
  
  
• Perfume / Fragrance Grade: Heavily diluted using synthetic additives for enhanced and long lasting aroma.

Note: Caveman Redux essential oils are 100% pure, Therapeutic Grade essential oils, unless otherwise specified. Certain oils such as Rose and Vanilla are sold in both unadulterated forms (pure essential oil or absolute) and adulterated form (Cosmetic Grade essential oil) due to high production costs and market demand.

1.2. How are Essential Oils made?

Essential oils are most commonly produced through a process known as steam distillation. During this process, plant material is placed in a distillation chamber and exposed to steam. The heat causes the plant’s volatile aromatic compounds to vapourise and travel with the steam into a separate condensation chamber.

As the vapour cools, it condenses into a liquid composed of water and essential oil. Because essential oils are hydrophobic and generally lighter than water, they separate and float on top of the distilled water (hydrosol). The essential oil is then collected.

Not all plants are suitable for steam distillation. Only plant material that contains sufficient volatile aromatic compounds will yield an essential oil using this method.

1.3. What are Absolutes or Absolute Oils?

Some delicate flowers and plants, such as Rose, Blue Lotus, and Vanilla, may be damaged by the heat of steam distillation or may yield very small quantities of essential oil. In these cases, a different method called solvent extraction is used to produce what is known as an "absolute".

In solvent extraction, a solvent (often ethanol) is used to dissolve the aromatic compounds from the plant material. The solvent is then evaporated, leaving behind a highly concentrated aromatic substance, which is referred to as the absolute. Absolutes contain aromatic compounds as well as waxes and resins that are not present in steam-distilled essential oils.

Both essential oils and absolutes are commonly used in aromatherapy and topical applications. Some plants, such as rose, can be processed into both forms. For example, rose petals can be steam distilled to produce Rose essential oil (often called "Rose Otto") or solvent extracted to produce Rose absolute, each with distinct aromatic and chemical profiles.

2. How to Use Essential Oils?

Many uses of essential oils can be generally classified as follows,

2.1. Topical Application: Using Essential Oils on the Skin and Hair

Essential oils can be topically applied on the skin or hair, when mixed with a carrier oil (base oil) or oil-soluble cosmetic products such as skin creams, lotions and shampoos. A carrier oil which does not have a strong smell of its own and which is easily absorbed by the skin is preferred. Examples include, Jojoba oil, Sweet Almond oil, Grapeseed oil, and Fractionated Coconut oil (MCT).

Most essential oils cannot be applied directly to the skin without being diluted, as it may cause allergic reactions. However less potent essential oils such as Sandalwood, and Lavender can be used undiluted on small areas of the skin in spot treatments. In all other cases, a carrier oil or another carrier such as a plant butter is recommended.

The dilution ratio depends on the potency of each essential oil and the intended application. As a rule of thumb, if applied on any area or portion of the body, essential oils should be diluted in a carrier at no greater concentration than 3% - 5% (3 drops of essential oil in 1 teaspoon of carrier). For massage or for application over a large area of the body, a 1-2% solution is generally considered safe (1 drop of essential oil in 1 teaspoon of carrier). For infants, using a 0.25% - 0.5% solution  is recommended.

When used in the bath, it has to be noted that essential oils are insoluble in water. Rose and Geranium essential oils are more water-affine than most oils. However essential oils are generally insoluble in water and are considered hydrophobic. Thus they will float on top of bath water and pass through the skin exposing oneself to the full strength essential oil. Hence only healthy concentrations have to be used in the bath and precautions have to be taken to avoid contact with the eyes.

Essential oils may be used in water-based sprays. However, If you use water as a carrier in spray, be sure to shake or mix the solution well before spraying. Essential oils dissolve well in alcohols such as ethanol and vodka. Such carriers are used in the formulation of perfumes and colognes.

Note: If you haven't tried an essential oil before and are unsure about an allergic reaction, it is recommended that a patch test is performed on inner elbow or wrist before application. Essential oils should never be directly burned or heated as the chemical structure could be changed due to incineration, diminishing its therapeutic value. 

2.1.1. What are the best essential oils for skincare?

The following essential oils are considered effective against the mentioned skin conditions,

• Dry, flaky, cracked skin (Vata skin) – Sandalwood, Vetiver, Chamomile, Clary Sage, Geranium, Lavender, Jasmine essential oils
• Sensitive, oily, and acne-prone skin (Pitta skin) – Turmeric, Sandalwood, Vetiver, Geranium, Lavender, Rose, Cedarwood, Tea Tree, Bergamot, Grapefruit, Cypress essential oils
• Normal skin (Kapha skin) – Vetiver, Sandalwood, Clary Sage, Lavender, Frankincense, Orange, Neroli, Rosemary essential oils
• Hyperpigmentation, dark spots and skin discolouration – Vetiver, Sandalwood, Turmeric, Lemon essential oils
• Aging skin – Vetiver, Sandalwood, Helichrysum
• Cellulite – Orange, Lemon, Black Pepper essential oils

Note: Avoid direct sun exposure for 12-18 hours after applying citrus oils such as Lemon, Orange and Lime essential oils due to photo-toxicity and UV sensitivity.

2.1.2. What are the best essential oils for haircare?

The following essential oils are considered effective against the mentioned hair conditions,

• Hair loss – Coriander, Peppermint
• Oily hair – Cedarwood, Lavender
• Hair growth – Rosemary, Coriander
• Split ends – Vetiver, Sandalwood
• Dandruff and dry scalp - Vetiver, Sandalwood
• Lice and nits – Tea Tree, Lavender

Note: Always dilute essential oils in a complementary carrier oil before topical application.

2.1.3. What are non-cosmetic topical applications of essential oils?

Certain essential oils can be used in non-cosmetic applications,

• Wintergreen – for pain relief
• Peppermint – for headaches and cooling the body (a source of natural menthol)
• Cinnamon – for warming the body
• Clove – for toothaches
• Turmeric and Citrus oils – for cleaning and disinfecting
• Eucalyptus and Citrus oils – for respiratory support
• Citronella – for repelling mosquitoes
• Turmeric – for repelling flies
• Peppermint – for repelling ants, cockroaches and spiders 

2.2. Aromatherapy: Using the Aroma of Essential Oils for Wellness

Essential oils can be used in aromatherapy with or without dilution. Aromatherapy is a therapy rooted in ancient traditions, that uses natural therapeutic aromas from flowers, leaves, roots etc., through methods like diffusion, direct inhalation, and massage to promote healing, immunity, calm, relaxation, or energy.

Inhalation brings essential oils in vapour form to the respiratory tract. As most essential oils contain antibacterial, and antimicrobial properties, they promote immunity and wellness. They also stimulate the limbic system and brings about the immediate release of hormones and neurotransmitters conducive to health and wellbeing.

2.2.1. How to Use Essential Oils in Aromatherapy?

The following wellness related applications are common in Aromatherapy,

• Eucalyptus, Citrus essential oils (Lime, Lemon, Orange etc) and Neroli: Alleviating colds, respiratory support, easing nasal congestion and sinusitis
• Coriander, Thyme, and Cajeput: May help ease and alleviate common flu symptoms
• Cinnamon, Clove, Turmeric, Cardamom, Lemongrass, Neroli and Citrus oils: Boosting immunity and purifying air
• Clove and Citrus oils: Boosting energy and concentration
• Cinnamon, Lavender, Sandalwood, Frankincense, Bergamot, Patchouli and Vetiver: Relaxation and anxiety
• Rose and Nutmeg: Aphrodisiac
• Lavender and Chamomile: Promoting sleep

Essential oils can be directly inhaled, steamed, diffused in a diffuser, used in candles, room sprays, sanitizer sprays, laundry, and cosmetic products. The most common methods of aromatherapy are as follows; 

• Direct Inhalation: Essential oils can be inhaled directly from the bottle for therapeutic benefits. 
  
• Steaming: Boil water, pour it into a bowl and put in 3 to 5 drops of essential oil such as Lime or Eucalyptus. Put a towel over your head, close your eyes and take a few deep breaths. Be careful not to get too close to the steam. 
  
• Diffusing: Essential oils can be diffused or evaporated using mechanical diffusers (reed diffusers) and electric aroma diffusers.

2.3. Oral administration

Generally, oral administration of essential oils is not recommended as a single drop of essential oil is a potent concentrate of the plant, regardless of the purity. Only certified Food-Grade essential oils are effectively refined and recommended for oral administration, regardless of the fact that it is unadulterated. 

Not all essential oils are qualified to be administered orally. Essential oils which come from digestible plants such as spices may be consumed after dilution. Due to the potency of essential oils, uncooked oral administration is not recommended without the prescription of a health care professional.

Due to its refreshing and antimicrobial properties, certain essential oils such as Clove, Turmeric, Cardamom, Ceylon Cinnamon, Nutmeg, Black Pepper, Lime, and Peppermint can be used in tooth pastes, mouth washes and oil pulling formulations to treat dental problems, and bad breath. Such essential oils can also be used in a gargle for soar throat discomfort. For example, one drop of Clove essential oil could be diluted in water and gargled before spitting out.

3. How to Make Essential Oil Blends / How to Blend Essential Oils?

Many essential oils can be blended together to formulate therapeutic blends. There is no definitive guide that specifies which essential oil is used to treat which health condition. Using essential oil blends in aromatherapy is a continuous process of studying the benefits of plants and using them in an effective manner for the targeted purpose, considering each oil’s properties. If the application is therapeutic in nature, the therapeutic value of the plant from which an essential oil is extracted has to be considered before deciding on its application.

In blending essential oils for fragrance, such blending could be done according to the note families (Top, Middle and Base) as the ultimate focus would be on the final aroma rather than its therapeutic value. The perfumery note of an essential oil refers to the rate at which the oil evaporates and the strength of its fragrance. Top notes evaporate more quickly and base notes more slowly. As a result, top note scents are perceived more quickly than base note scents. Essential oils can also be blended according to the family of its origin.

4. Shelf Life and Expiration of Essential Oils

Essential oils do not truly expire but oxidise over time. Citrus oils typically last 1 - 2 years, most floral and herbaceous oils 3 - 5 years, and woody or resinous oils 5 - 10+ years, with shelf life extended by proper storage away from heat, light, and air. Certain essential oils such as Sandalwood essential oil may improve in aroma and depth as they age when properly stored. 

Note: This is not an all-inclusive guide. If you are unsure about which application method to use with essential oils, consult a qualified aromatherapist or a healthcare professional.