ESSENTIAL OIL SAFETY TOXICOLOGY AND HUMAN PHYSIOLOGY
Dr. James L. Symes Professor of Chemistry _________________________________________________________________________________________________ Adverse Skin Reactions From Essential Oil Use DERMAL IRRITATION: A chemical burn due to the corrosive nature of the oil, resulting in skin damage and an inflammatory response. SENSITIZATION: An allergic reaction resulting in a histamine response. PHOTO-‐TOXICITY: A photo-‐active molecule is activated by sunlight and releases energy to the skin resulting in a burn. _________________________________________________________________________________________________
Mucous Membrane Irritants Box 6.1 Mucous Membrane irritants A: Severely irritating Recommendation—do not use on mucous membrane. B: Strongly irritating Recommendation—do not use at more than 1% concentration on mucous membrane. C: Moderately irritating Recommendation—do not use at more than 3% concentration on mucous membrane. * These oils rated here for their irritant effects, can also cause powerful allergic reactions D: Non-‐irritant Caution—some oils may occasionally cause irritation if used undiluted.
Citronella Coriander Cumin Cypress Dill seed Lavender Lemon Lemongrass Marjoram (sweet) Myrrh Neroli Nutmeg Orange
Horseradish Clove leaf Clove stem Massoia Oregano Bay leaf (W. Indian) Caraway Cassia Cinnamon Bark Pimento berry
Mustard
Angelica root Anise Basil Bergamot Buchu Cardamom Eucalyptus Fennel (bitter) Fennel (sweet) Frankincense Galnbanum Parsley herb Parsley seed Petitgrain Pine (dwarf) Rose A. Rose otto Rosewood Rue
Carrot seed Cedarwood (atlas) Cedarwood (VA) Chamomile (German) Chamomile (Roman) Clary Sage Geranium Grapefruit Hyssop Immortelle Juniper Sage (Dalmation) Sandalwood Sassafrass Tarragon Tea Tree Vetiver Wintergreen Yarrow, Ylang-‐Ylang
Pimento leaf Savory Thyme Thyme (wild) Cinnamon leaf Clove Bud Cornmint Laurel Peppermint Spearmint
Grading of Skin Irritation of Essential Oils Box 7.1 Grading of Skin Irritancy These oils were all tested concentrations between the max. use level of each on human subjects at 1% & 3%, depending on oil in fragrances. A: Severely irritant Horseradish Mustard B: Strongly irritant Cade (rectified) Garlic ?
Massoia Onion ? Pine (dwarf) (only if oxidized) C: Moderately irritant Clove bud Flouve Clove leaf Parsley leaf Abies alba (cones) Clove stem Parsleyseed Ajowan ? Fennel (sweet) Pimento berry Betel leaf ? Fig leaf Pimento leaf Birch (sweet) Fir needle (Siberian) Rue Bitter almod FFPA* Hyacinth Cassia Laurel Cinnamon bark Ocimum gratissimum Cinnamon leaf Oregano D: Very mildy irritant Eucalyptus citriodora Lime Abies alba (needles) Elemi (distilled) Ale Cedarwood(VA) Fennel (bitter) Linaloe Almond (bitter) Chamomile(Ger) Fenugreek Lovage Angelica root Chamomile(Rom) Flouve Mace Angelica seed Citronella Frankincense Mandarin(expressed) Anise Clary sage (Fr.) Galbanum Marjoram (Spanish) Armoise Copaiba Geranium (Algerian) Mastic Basil ? Coriander Geranium (Bourbon) May chang Basil (W.Indian) Costus (severe Geranium (Maroc) Mimosa Benzoin ? Sensitizer) Ginger Myrtle Bergamot Cumin Graperfruit Narcissus Bergamot mint Cypress Guaiacwood Nutmeg Birch (sweet) Davana Ho leaf Orange (bitter) Birch tar Dill seed Honeysuckle Orange (sweet) Cubeb Eu de brotus Hay Orange flower Boldo Eucalyptus ? Immortelle Palmarosa Buchu? Elecampane Jonquil Patchouli Cabreuva (severe sensitizer) Juniper Pennyroyal(Eur) Camphor (white) Karo karounde Pennyroyal(N. Camphor (yellow) Labdanum American) Cananga Lavandin Pepper (black Carraway Birch (sweet) Lavender Perilla Carrot seed Lemon Peru balsam Cedarwood (AT) Lemon leaf Peruvian pepper Cedarwood (TX) Lemongrass Petitgrain (bigrade) E: Non-‐irritant Cascarilla Celery seed Abies alba Clary sage (Russian) Ambrette seed Cornmint Anise (star) Deertongue Broom Dill weed Cajeput Fir needle (Canadian) Calamarus Gurjun balsam Camphor (brown) Hyssop Cardamom Jasmine
Terebinth (only if oxidized)
Sage (dalmation) Verbena Sassafras Wintergreen Savory (summer) Savory (winter) Spruce hemlock Taget Tarragom Tejpat ? Thyme Thyme (wild) ? Petitgrain (Paraguay) Rose Abs. Rose otto Rosemary ? Sandalwood Savin ? Spearmint Spike lavender Spruce Star anise Tangelo Tangerine Tansy Tea Tree Thuja Tobacco leaf Tonka Tumeric Valerian ? Verbena Vetiver Wormseed Wormwood Yarrow ? Ylang-‐ylang Juniperus phoenicea Snakeroot Labdanum Violet leaf Marjoram (sweet) Myrrh Neroli Phoenician juniper Orris Pine (scotch) Rosewood Sage (Spanish)
Grading of Skin Sensitization of Essential Oils Box 7.2 Grading of skin sensitization A: Severe Do not use on skin or mucous membrane. Costus Elecampane Tea Verbena B: Strong Best avoided on both skin and mucous membrane. Do not use unless diluted to suitable concentration – percentages shown are maximums to avoid sensitization. Do not use at all on hypersensitive, diseased or damaged skin, or on infants. Cassia Fennel Garlic Oakmoss Verbena (<0.1%) ( bitter,oxidized) (patch test first at (<0.6%) (<0.1%) 0.1%) Cinnamon bark Fig leaf Treemoss (<0.1%) (<0.6%) Also oxidized oils, especially pine and spruce oils. C: Slight risk Anise Laurel leaf Melissa Perilla Star anise Catnip Lavender Myrrh Pine (dwarf) Ylang-‐ylang Khella Lemongrass Onion Pine (Scotch) May chang D: Negotiable risk Almost certainly will not cause skin sensitization. Abies alba (cones) Cedarwood (atlas) Fir needle (Siberia) Marjoram (Spanish) Rosemary Abies alba (needls) Cedarwood (TX) Fouve Marjoram (sweet) Rosewood Ale Cedarwood (VA) Frankincense Mastic Rue Almond (bitter) Chamomile (Germn) Galbanum Methyl salicylate Sage (Dalmation) Almond (bitter) FFPA Chamomile (Roman) Geranium (Algerian) Mimosa Sage (Spanish) Ambrette seed Celery seed Geranium(Moroccan Myrrh Sandalwood Angelica root Cinnamon leaf Geranium (Reunion) Myrtle Sassafras Angelica seed Clary sage (French) Ginger Narcissus Sassafras (Brazilian) Armoise Clary sage (Russian) Grapefruit Neroli Savory (Summer) Basil Clove bud Guaiacwood Nutmeg Snakeroot Bay (W. Indian) Clove leaf Gurjun balsam Orange (bitter) Spearmint Benzoin Clove stem Hay Orange (sweet) Spike Lavender Bergamot Copaiba Ho leaf Orange flower Spruce Bergamot mint Coriander Honeysuckle Oregano Star anise Birch (sweet) Cornmint Hyacinth Orris Taget Birch tar Cubeb seed Hyssop Palmarosa Tangelo Boldo leaf Cumin Immortelle Parsley leaf Tangerine Broom Cypress Jasmine Parsleyseed Tansy Cabreuva Davana Jonquil Patchouli Tarragon Cade Deertongue Juniper Pennyroyal (Eur.) Tea Tree Cajeput Dill seed Karo karounde Pepper (black) Terebinth Calamus Dill weed Labdanum (cistus) Peru balsam Thuja Camphor (brown) Eau de brotus Lavandin Peruvian pepper Thyme Camphor (yellow Elemi Lavender Petitgrain (Bigrade) Tobacco leaf Camphor (white) Eucalyptus globulus Lemon Petitgrain (Parguay) Tonka Cananga Eucalyptus citriodora Lemon leaf Phoenician juniper Turmeric Caraway Fennel (bitter, Lime (distilled) Pimento leaf Vetiver Cardamon oxidized) Linaloe Rose (French) Violet leaf Carrot seed Fennel (sweet) Lovage Rose (Bulgarian) Wormseed Cascarilla Fenugreek Mace Rose (Morrocan) Wormwood Fir needle (Canada) Madarin Rose (Turkish) Possible risk of sensitization These oils have not been tested for sensitization. Their composition suggests that they may cause sensitization but the risk is very small. Combava (leaf) Hinoki (root) St. John’s Wort Eucalyptus staigeriana
Essential Oil Photo-‐toxicity Psoralens
-‐ epidermis
-‐ dermis Psoralens in epidermis UV Rays
Psoralens store energy From UV
Illustration of a photo-‐toxic agent absorbing UV light and then releasing it in a burst to the skin From Tisserand, 1995, Churchil Livingstone, London
Energy released into dermis and lower epidermis, causing damage.
Photo-‐toxic Molecules
OCH3
O
O
O Bergapten
O
O
OCH3 Xanthotoxin
O
Essential Oil Photo-‐toxicity Box 7.4 Recommended maximum use levels to avoid phototoxic reactions A: Severe It is recommended that these oils are not used on the skin, or in any aromatherapy products intended for retail. Fig leaf absolute
Verbena oil 6
B: Strong We recommend that treated skin should not be exposed to sunlight or UV lamps for at least 12 hours, if used at levels higher than those indicated. Retail products should not contain these oils at levels higher than those indicated. Taget Verbena absolute Bergamot Cumin Lime (expressed) Angelica root Rue Opopanax
0.05% 0.2% 0.4% 0.4% 0.7% 0.78% 0.78% No level set
C: Moderate We recommend that treated skin should not be exposed to sunlight or UV lamps for at least 12 hours, if used at levels higher than those indicated. Retail products should not contain these oils at levels higher than those indicated. Orange (bitter, expressed )4 Lemon (expressed) Grapefruuit (expressed)
1.4% 2.0% 4.0%
Possible Carcinogenic Essential Oil Components
1. Methyleugenol 2. Estragole 3. Anethole 4. Eugenol 5. Elemicin 6. Safrol 7. Isosafrol 8. Asarone 9. d-‐Limonene 10. Benzopyrene
(Snakeroot, Russian and French Tarragon, East Indian Nutmeg) (Tarragon, Basil, Ravensara, Fennel, Chervil) (Nutmeg, Anise, Fennel, Star Anise) (Bay, Cinnamon, Clove, Pimento, Tejepat) (Nutmeg, Elemi, Mace, Parsley) (Camphor, Cinnamon, Mace, Sassafras, Nutmeg, Star Anise) (Ylang-‐ylang) (Calamus species) (All citrus oils) (Unrectified cade)
Essential Oils Involved in Documented Cases of Acute Poisoning Camphor Citronella Cinnamon Clove Eucalyptus Hyssop Nutmeg Parsley Pennyroyal Thuja Sassafras Wintergreen Wormseed
Essential Oil Toxicity Ratings Oral toxicity A: LD 50 up to 1 g/kg Oil
Toxic component
Boldo leaf Mustard
LD 50 (g/kg) 0.13 0.15
Wormseed Armoise
0.25 0.37
Ascaridole 60-‐80% Thujone 35%
Pennyroyal (Eur.) Tansy
0.40 0.73*
Pulegone 55-‐95% Thujone 66-‐81%
Thuja
0.83
Thujone 39-‐80%
Calamus
0.84
Asarone 45-‐80%
Wormwood
0.96
Thujone 34-‐71%
Almond bitter)
0.96
Prussic acid 3%
Artemisia arborescens
? +-‐
Iso-‐thujone 30-‐45%
Buchu (B. crenulata)
?
Pulegone 50%
Horseradish
?
Allyl isothiocyanate 50%
Lanyana
?
Thujone 4-‐66%
Pennyroyal (N. Am.)
?
Pulegone 60-‐80%
Southernwood
?
Thujone (major component)
Western red cedar
?
Thujone 85%
Ascaridole 16% Allyl isothiocyanate 99%
Essential Oil Toxicity Ratings Oral toxicity B: LD 50 between 1 g/kg and 2 g/kg _________________________________________________________________________________________________ Oil LD 50 (g/kg) _________________________________________________________________________________________________ Methyl salicylate (wintergreen) 1.20 Cornmint 1.25 Savory (summer) 1.37 Clove leaf 1.37 Basil 1.40 Hyssop 1.40 Bitter almond FFPA+ 1.49 Sassafras (Brazilian) 1.58 Myrrh 1.65 Birch (sweet) 1.70 Bay leaf (W. Indian) 1.80 Oregano 1.85 Sassafras 1.90 Tarragon 1.90 Tea tree 1.90 Buchu (B. betulina) ? Savin ? _________________________________________________________________________________________________
Essential Oil Toxicity Ratings Oral Toxicity C: LD50 between 2 g/kg and 5 g/kg Ajowan ? Anise Bay leaf (laurel) Cajeput Samphor (brown) Camphor (yellow) Caraway Cassia Cinnamon bark Cinnamon leaf Clove bud Clove stem Coriander Costus Cumin Dill seed Dill weed Elecampane ? Elemi Eucalyptus Fennel (bitter)
Fennel (sweet) Ho leaf Lovage Mace Marjoram (sweet) Neroli Nutmeg Peppermint ? Perilla Peru balsam Pimento berry? Pimento leaf Rosewood Rue Sage Snakeroot Spike lavender Star anise Taget Thyme Yarrow
Abies alba (cones) Abies alba (needles) Angelica root Angelica seed Benzoin (resinoid) Bergamot Bergamot mint Birch tar Cabreuva Cade Camphor (white) Cananga Cardamon Carrot seed Cascarilla Cedarwood (atlas) Cedarwood (Texas) Cedarwood (VA) Celery seed Chamomile (German) Chamomile (Roman) Citronella Clary sage Copaiba Cupeb seed Cypress
_________________________________________________________________________________________________
Essential Oil Toxicity Ratings Oral toxicity D: LD 50 over 5 g/kg _________________________________________________________________________________________________ Davana Marjoram Eucalyptus citriodora May Chang Fir needle (Canadian) Orange (bitter) Fir needle (Siberian) Orange (sweet) Frankincense ? Palmarosa Galbanum Patchouli Geranium (Algeria) Pepper (black) Geranium (Reunion) Petitgrain Geranium (Morocco) Petitgrain Ginger Pine Grapefruit Rose Guaiacwood Rose (otto) Gurjun Sage (Spanish) Immortelle Sandalwood Jasmine Schinus molle Juniper Spearmint Juniperus phoenicea Spruce Labdanum Tangerine Lavandin Terebinth ? Lavender Valerian Lemon Verbena Lemongrass Vetiver Lime Violet leaf Linaloe Ylang – ylang Mandarin (expressed) _________________________________________________________________________________________________
Essential Oil Liver Toxicity Components and corresponding essential oils, which have a potential for liver toxicity. _________________________________________________________________________________________________ Component
Oil
Trans-‐anethole
Anise, fennel, star anise
Cinnamaldehyde
Cassia, cinnamon bark
Estragole
Basil, tarragon
Eugenol
Bay (W. Indian), betel leaf, cinnamon leaf, clove bud, clove stem, clove leaf, Ocimum gratissumum, pimento berry, pimento leaf, tejpat leaf Not found in significant quantities in any essential oil.
Methyleugenol
d-‐pulegone
Buchu (B. Crenulata), pennyroyal
Safrole
Camphor (brown), camphor (yellow), sassafras
Unknown
Savin
Neurotoxicity of Essential Oils Potential Convulsant Effects Oil
Convulsant component
Percentage of component in oil A: Do not use at all in anyone suspected of being vulnerable to seizures, or in anyone with a fever. Annual wormwood Artemisia ketone 35-‐63 Aromoise Thujone 35 Camphor 30 Artemisia arborescens Camphor 12-‐18 Thujone 30-‐45 Artemisia caerulescens Camphor major components Thujone major components Balsamite (camphor CT) Camphor 72-‐91 Buchu (B. crenulata) Pulegone 50 Camphor (white) Camphor 35-‐45 Ho leaf (cdamphor/safrole CT Camphor 42 Hyssop Pinocamphone 40 Iso-‐pinocamphone 35 Lanyana Thujone 65 Lavender cotton Artemisia ketone 10-‐45 Pennyroyal Pulegone 55-‐95 Sage (Dalmation) Camphor 26 Thujone 50 Tansy Thujone 66-‐81 Thuja Thujone 39-‐80 Western red cedar Thujone 85 Wormwood Thujone 34-‐71 B: Avoid orally in anyone suspected of being vulnerable to seizures, or in anyone with a fever. Use with caution externally. Lavandula stoechas Camphor 15-‐30 Sage (Spanish) Camphor 11-‐36 C: Probably safe to use externally. Caution required orally in anyone suspected of being vulnerable to seizures, or anyone with a fever. Cornmint Menthone 15-‐30 Lavandin Camphor 5-‐15 Peppermint Mentone ? 19 Rosemary Camphor 10-‐20 Rue 2-‐undecanone ? 31-‐49 Spike lavender Camphor 10-‐20 Yarrow (camphor CT) Camphor 10-‐20
Those suspected of being vulnerable to seizures include people who have had epilepsy in the past, anyone with a strong family history of epilepsy and anyone with a fever. People with epilepsy suppressant medication may not be especially vulnerable. Many of the oils listed here are contraindications in aromatherapy due to general toxicity.
Sedative Effects of Essential Oils Box 6.4 Sedative Essential Oils Almond (bitter) Asafoetida Calamus Chamomile (German) Clary sage Elemi Galbanum Lavender Marjoram Melissa
Neroli Nutmeg Rose Rosewood Savory Taget Valerian Violet leaf Yarrow
Box 6.3 Essential oil constituents which can cause central nervous depression (sedation) Trans-‐anethole Geraniol Beta-‐asarone Linalool Benzaldehyde Linalyl acetate Citronellol Methyleugenol Elemicin Myristicin Iso-‐elemicin Iso-‐myristicin Eugenol Nerol Eugenol methyl ether Nerolidol Farnesol Terpineol