1. Fragrance/Parfum
2. Title: Phthalates in Cosmetics

Link: https://www.fda.gov/cosmetics/cosmetic-ingredients/phthalates-cosmetics 

Takeaway: The term 'fragrance' does not disclose the individual fragrance ingredients, so when we use products with fragrance, we may be unknowingly exposing ourselves to harmful ingredients such as phthalates, aldehydes, and parabens.

1. Title: Evaluation of pollutants in perfumes, colognes and health effects on the consumer: a systematic review 

Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC9163252/ 

Takeaway: Several phthalates have been identified as endocrine-disrupting chemicals and have been associated with adverse health effects. This systematic review concluded that phthalates, aldehydes, parabens, and aluminum-based salts were among the most commonly reported contaminants in perfumes and other aromatic products. Across the studies reviewed, exposure to these compounds was associated with outcomes including allergies, skin irritation, migraine headaches, nervous system effects, reproductive disorders (particularly in males), and potential links to diseases such as breast cancer. The authors note, however, that further research is needed to establish causal relationships for many of these health outcomes.

1. Title: Fragrance contact allergy: a clinical review

Link: https://pubmed.ncbi.nlm.nih.gov/14572300/ 

Takeaway: Fragrance ingredients are a common source of daily exposure and are among the most frequent causes of allergic contact dermatitis. Patch testing with the fragrance mix identifies fragrance allergy in approximately 10% of eczema patients tested and indicates sensitization in an estimated 1.7–4.1% of the general population. Fragrance allergy occurs most commonly in women with facial or hand eczema. Of the approximately 2,500 fragrance ingredients used in cosmetics, at least 100 are recognized contact allergens. 

1. Title: Fragrance Free Skincare: Everything You Need to Know

Link: https://simpleskincarescience.com/fragrance-free-skincare/ 

Takeaway: Fragrance is a well-established cause of allergic contact dermatitis. Individuals with eczema, impaired skin barriers, or a history of reactions to scented products are more likely to experience problems and may benefit from avoiding fragrance allergens.

1. Title: Health and societal effects from exposure to fragranced consumer products

Link: https://pubmed.ncbi.nlm.nih.gov/27896043/ 

Takeaway: This study done in Australia looked at the health effects and perception of fragranced products and found that of the 1098 participants, 33 percent reported at least one health problem associated with products containing artificial fragrance, including skin problems and headaches.

1. Title: Fragrances: Contact Allergy and Other Adverse Effects

Link: https://pubmed.ncbi.nlm.nih.gov/31433384/ 

Takeaway: Even if something is marketed as “natural”, we can’t assume that it is safe for everyone. For example, compounds like linalool, which is found in lavender extract, is one of the most frequent fragrance sensitizers. 

Note from Bodywork Supply: Because massage therapists experience unusually high occupational exposure, it was a no-brainer to avoid fragrance in our formula. I wanted to create a product with the lowest risk for irritation, sensitization, contact dermatitis, or any other negative health outcome, which is why TheraGlide Lotion and Cream will be fragrance free!

      2. Allergens

1. Title: Food Allergies: The “Big 9”

Link: https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/food-allergies-big-9 

Takeaway: “The nine leading causes of food allergies identified in the US are milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybean, and sesame.” The ones in bold are found in massage mediums. 

1. Title: Allergenicity of Refined Vegetable Oils

Link: https://pubmed.ncbi.nlm.nih.gov/10722892/ 

Takeaway: Oils derived from common allergens are often highly refined, which substantially reduces allergenic proteins. However, because trace protein residues may remain, very sensitive individuals may still choose to avoid these ingredients. I would rather error on the side of caution and not have any allergen oils in my medium, as a large portion of their skin will be in contact with the product. Although the risk may be lower due to the refining process of the oils, I’d rather have that risk be 0 for peace of mind for both myself and my client.

Note from Bodywork Supply: If common allergen oils aren’t a necessary ingredient, and a product with the same excellent workability can be created without them, we’re going to stay away from them altogether. That was the thought process behind deciding to exclude the top 9 allergen oils from TheraGlide Lotion and Cream.

3. Diazolidinyl Urea or Imidazolidinyl Urea (Formaldehyde-Releasing Preservatives)

Diazolidinyl urea and Imidazolidinyl Urea are preservatives that slowly release small amounts of formaldehyde to help prevent microbial growth. It has been associated with allergic contact dermatitis, particularly in individuals who are sensitive to formaldehyde. The rate of contact allergy to FRs is ~8% in the US.

1. Title: Diazolidinyl urea: incidence of sensitivity, patterns of cross-reactivity and clinical relevance

Link: https://pubmed.ncbi.nlm.nih.gov/8156757/

Takeaway: “Diazolidinyl urea (DIAZ) is a formaldehyde-releasing preservative used in cosmetics and personal-care products, which has been identified as a sensitizing agent in contact dermatitis.”

1. Title: Contact allergy to and allergic contact dermatitis from formaldehyde and formaldehyde releasers: A clinical review and update

Link: https://onlinelibrary.wiley.com/doi/10.1111/cod.14089

Takeaway: 

“Although its counterpart imidazolidinyl urea is more widely used, diazolidinyl urea is a more-potent sensitizer, accounting for higher overall rates of sensitization, being more pronounced in the United States (2%–4%) as compared to Europe (0.5%–1.5%).”

“Sensitization rates to the widely used releaser imidazolidinyl urea have ranged between 2% and 3% (up to 3.8% in hand dermatitis patients) in the United States”

ACD=allergic contact dermatitis

“Occupations at risk for occupational ACD from FA/FRs comprise, among others, metalworkers, health care workers (eg, hemodialysis nurses, laboratory technicians, embalmers), hairdressers and beauticians, painters, veterinary and dental students, and laborers in the food-processing industry.”

Note from Bodywork Supply: We do not formulate with formaldehyde-releasing preservatives, as it is our top priority to choose ingredients that support skin safety/health.

4. Botanical Extracts

1. Title: [Compositae dermatitis]

Link: https://pubmed.ncbi.nlm.nih.gov/17919303/ 

Takeaway: "The frequency of contact allergy to Compositae in Europe is higher than previously believed. It occurs most frequently in middle-aged and elderly persons, but also in all age groups. During the two past decades a more equal sex ratio has been established. The prevalence varies from 0.7-1.4% in the general population, up to 4.5% among occupationally exposed persons."

1. Title: The coumarin herniarin as a sensitizer in German chamomile [Chamomilla recutita (L.) Rauschert, Compositae]

Link: https://pubmed.ncbi.nlm.nih.gov/20557339/

Takeaway: The clinical results suggest that herniarin indeed is one of the non-sesquiterpene lactone sensitizers in German chamomile and that sensitization may occur through, for example, external use of chamomile tea or use of chamomile-containing topical herbal remedies.

1. Title: Identification of a compound isolated from German chamomile (Matricaria chamomilla) with dermal sensitization potential

Link: https://pubmed.ncbi.nlm.nih.gov/28109818/ 

Takeaway: Despite its reputation as a medicinal plant, there are numerous reports of allergic reactions in people who topically applied products containing chamomile extracts (Ketel, 1987, Ketel, 1982, West and Maibach, 1995, Foti et al., 2000, Rudzki et al., 2003). Both German and Roman chamomile have been mentioned in these, and other, reports of adverse effects but there is some uncertainty concerning the allergens involved. The dermal sensitization properties of chamomile have been reported to be associated with sesquiterpene lactones such as matricarin and anthecotulide (Ketel, 1987, Lundh et al., 2006).

Note from Bodywork Supply: With the goal of creating a product that minimizes that risk for irritation/sensitization/dermatitis, we decided to exclude botanical extracts. The long-term and real-world use of massage mediums was considered and prioritized.

5. Essential Oils

1. Title: Tea tree oil: contact allergy and chemical composition

Link: https://pubmed.ncbi.nlm.nih.gov/27173437/ 

Takeaway: Of all essential oils, TTO has caused most (published) allergic reactions since the first cases were reported in 1991. In routine testing, prevalences of positive patch test reactions have ranged from 0.1% to 3.5%.

1. Title: Contact sensitization to essential oils: IVDK data of the years 2010–2019

Link: https://onlinelibrary.wiley.com/doi/10.1111/cod.14126 

Takeaway: “Twelve EOs were patch tested in an aimed manner in 10 930 patients, of whom 908 (8.3%) reacted to at least 1 EO. Only 6 EOs elicited more than 1% positive patch test reactions: ylang ylang (I + II) oil (3.9%), lemongrass oil (2.6%), jasmine absolute (1.8%), sandalwood oil (1.8%), clove oil (1.6%) and neroli oil (1.1%). Concomitant reactions among EOs or to EOs and fragrances were frequent.” 

Although many people can tolerate essential oils well, it is a recognized cause of allergic contact dermatitis, and the risk may be greater with frequent occupational exposure.

1. Title: Allergy to tea tree oil: retrospective review of 41 cases with positive patch tests over 4.5 years

Link: https://pubmed.ncbi.nlm.nih.gov/17535193/ 

Takeaway: “We retrospectively reviewed our patch test data at the Skin and Cancer Foundation Victoria over a 4.5-year period and identified 41 cases of positive reactions to oxidized tea tree oil of 2320 people patch-tested, giving a prevalence of 1.8%. The tea tree oil reaction was deemed relevant to the presenting dermatitis in 17 of 41 (41%) patients.” 

1. Title: Degradation products of monoterpenes are the sensitizing agents in tea tree oil

Link: https://pubmed.ncbi.nlm.nih.gov/10357714/ 

Takeaway: “Tea tree oil kept in open and closed bottles or other containers undergoes photooxidation within a few days to several months, leading to the creation of degradation products that are moderate to strong sensitizers. Peroxides, epoxides and endoperoxides, like ascaridol and 1,2,4-trihydroxy menthane, are formed. These must be considered responsible for the development of allergic contact dermatitis seen in individuals treating themselves with the oil.” 

1. Title: Essential Oils, Part IV: Contact Allergy

Link: https://pubmed.ncbi.nlm.nih.gov/27427818/ 

Takeaway: “Nearly 80 essential oils (including 2 jasmine absolutes) have caused contact allergy. Fifty-five of these have been tested in consecutive patients suspected of contact dermatitis, and nine (laurel, turpentine, orange, tea tree, citronella, ylang-ylang, sandalwood, clove, and costus root) showed greater than 2% positive patch test reactions.”

1. Title: Autoxidation of linalyl acetate, the main component of lavender oil, creates potent contact allergens

Link: https://pubmed.ncbi.nlm.nih.gov/18154552/ 

Takeaway:  “We have in previous studies shown that linalool, present in lavender oil, autoxidizes on air exposure, forming allergenic oxidation products. Oxidized linalool was found to be a frequent cause of contact allergy in a patch test study on consecutive dermatitis patients. Linalyl acetate, the main component of lavender oil is commonly used as a fragrance chemical in scented products. Because of structural similarities, linalyl acetate should also be susceptible to oxidation on air exposure, forming similar oxidation products as linalool.”

“Autoxidation increased the sensitizing potency of linalyl acetate, and a 10 weeks oxidized sample gave an EC3 value of 3.6%. As for linalool, the hydroperoxides were shown to be the oxidation products with the highest sensitizing potency.”

Linalool is widely used in fragranced products and essential oils, including lavendar, but it is a recognized cause of allergic contact dermatitis, with the risk increasing as the ingredient oxidizes over time.

1. Title: Air-oxidized linalool: a frequent cause of fragrance contact allergy

Link: https://pubmed.ncbi.nlm.nih.gov/22906042/ 

Takeaway: “Linalool is a common fragrance terpene that, in pure form, is not allergenic or is a very weak allergen. However, linalool autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a Swedish study, oxidized linalool 6.0% in petrolatum (pet.) gave 5% positive patch test reactions in 2500 dermatitis patients.” “Overall, 6.9% (range 3-13%) of the patients showed positive patch test reactions to oxidized linalool. Doubtful reactions were found in 9.2% of the patients (range 0-36%). Few irritant reactions were seen.” “

1. Title: Fragrances: Contact Allergy and Other Adverse Effects

Link: https://pubmed.ncbi.nlm.nih.gov/31433384/ 

Takeaway: “The most frequent sensitizers are linalool and limonene hydroperoxides, hydroxyisohexyl 3-cyclohexene carboxaldehyde, treemoss and oakmoss absolute, isoeugenol, cinnamyl alcohol, and cinnamal.” 

Note from Bodywork Supply: Essential oils may be popular due to their association with being “natural” and having potential benefits at certain doses, some of them come with risks, especially if used frequently and over prolonged periods of time. Consequently, we decided to keep essential oils out of our products to protect the skin of bodyworkers whose skin is in contact with their medium for many hours each week.