Survey and health assessment of chemical substances in massage oils
8 User exposure
The assessment of exposure to fragrance substances in massage and body oils is based on the analysed content of fragrance substances in selected oils on the Danish market (Chapter 6) and is performed in accordance with the principles in the EU Technical Document (TGD) (33) and SCCNFP’s guidelines (34). The internal body dose (Systemic Exposure Dose, SED) is estimated in a worst case scenario for 2 model persons by applying standard parameters from TGD. The safety risk of exposure to fragrance substances in massage, baby, body and essential oils is assessed by calculating the MoS (Margin of Safety). The calculation is based on NO(A)EL, possibly LOEL of the toxicological profiles prepared in this survey project and previous survey projects (13), (14) and the estimated SED of the exposure assessment.
8.1 Exposure assessment
Fragrance substances in massage and body oils can be absorbed through the skin. The fragrance substances are volatile at room- and skin temperature and can be inhaled after evaporation from the greased areas of the skin. Therefore, it is relevant to include calculation of inhalation in the dose estimation. However, it has not been possible to procure information about the effect of fragrance substances by inhalation. Owing to this, assessment of the systemic dose (SED) is only performed by dermal exposure and absorption through the skin. A worst-case scenario assuming that the total amount of fragrance substances in the applied oil is absorbed through the skin is used to estimate the dose. Therefore, calculation of absorption by inhalation makes no different.
The EU has assessed 26 fragrance allergens. 19 of them were found in the analysed massage, baby, body oils and essential oils. In the massage, baby and body oils were found 14 different fragrance substances and in the essential oils 16. The daily exposure of these 19 fragrance substances has been calculated for two model persons, an adult of 60 kg and a baby of 5 kg (< 1 year). The daily exposure was calculated for the highest measured content of fragrance substances in massage- or body oils. A separate scenario for the essential oils was set up, because they are mixed with a basic oil in the proportion 1:10, before application.
The following calculation is used as worst-case scenario with dermal absorption as the only exposure route for massage, baby and body oils.
Weight of person, adult 60 kg
Weight of person, baby < 1 year (35) 5 kg
Number of applications per day (33) 1
Applied amount per application for adult (33) 10 g
Applied amount per application for baby 5 g
Material in massage oils
(Example: Benzyl benzoate, cf. Table 6-2 or 6-6): 1150 mg/kg
Absorption through the skin 100%
It is assessed that the amount of massage, baby or body oil, which is applied to a baby, does not exceed 50% of the amount applied to adults. The estimate is based on the body area of babies (~ 0.5 m²), which is considerably smaller than that of adults (~ 1.8 m²). As a smooth layer is applied to the body, the body area is decisive for the amount of applied oil (36).
Daily exposure, benzyl benzoate, adult:
Daily exposure, benzylbenzoate, baby (< 1 year):
The daily dose (SED) of the 14 fragrance substances in massage and body oils is calculated as mg per kg bodyweight per day (mg/bw/day) for the two model persons. The calculation is based on the maximum content of fragrance substances found in the oils in products for adults (chapter 6). The results are shown in table 8-1-
Table 8-1 Daily dose of two model persons of fragrance substances found in selected massage and body oils on the Danish market in the spring of 2005
| Fragrance substances | Max. content in the products (mg/kg) | Daily dose, adult, 60 kg (SED) (mg/kg bw/d) |
Daily dose, baby, 5 kg, (SED) (mg/kg bw/d) |
| Benzyl alkohol | 220 | 0.037 | 0.22 |
| Benzyl benzoate | 1150 | 0.19 | 1.15 |
| Benzyl cinnamate | 245 | 0.041 | 0.25 |
| Benzyl salicylate | 125 | 0.021 | 0.13 |
| Cinnamyl alkohol | 45,5 | 0.0076 | 0.046 |
| Cinnamal | 210 | 0.035 | 0.21 |
| Citral | 1750 | 0.29 | 1.8 |
| Citronellol | 460 | 0.077 | 0.46 |
| Coumarin | 330 | 0.055 | 0.33 |
| Eugenol | 55 | 0.0092 | 0.055 |
| Farnesol | 135 | 0.023 | 0.14 |
| Geraniol | 1250 | 0.21 | 1.25 |
| d-Limonene | 9250 | 1.54 | 9.25 |
| Linalool | 8050 | 1.34 | 8.05 |
The daily dose (SED) of the 16 fragrance substances in essential oils is calculated as mg per kg bodyweight per day (mg/kg/day) for the two model persons. The calculation is based on the highest content of fragrance substances found in the oils, cf. chapter 6. Before application, the user will mix the essential oil with a basic oil. According to the instructions that often follow the purchased essential oils, 6 drops (» 1 ml) are mixed with approx. 10 ml basic oil before application, which means that the essential oil is diluted approx. 10 times. The results can be seen in table 8-2.
Table 8-1 Daily dose of two model persons of fragrance substances found in selected essential oils mixed with basic oils on the Danish market in the spring of 2005
| Fragrance substance | Max. content in the products (mg/kg) | Max. content in the mixed products (mg/kg) | Daily dose, Adult, 60 kg (SED) (mg/kg bw/d) |
Daily dose, Baby, 5 kg. (SED) (mg/kg bw/d) |
| Benzyl alkohol | 140 | 14 | 0.0023 | 0.014 |
| Benzyl benzoate | 79.5 | 7.95 | 0.0013 | 0.0080 |
| Cinnamyl alkohol | 13.5 | 1.35 | 0.00023 | 0.0014 |
| Cinnamal | 14.5 | 1.45 | 0.00024 | 0.0015 |
| Citral | 32500 | 3250 | 0.54 | 3.3 |
| Citronellol | 47500 | 4750 | 0.79 | 4.8 |
| Eugenol | 225 | 22.5 | 0.0038 | 0.023 |
| Farnesol | 76 | 7.6 | 0.0013 | 0.0076 |
| Geraniol | 23000 | 2300 | 0.38 | 2.3 |
| Hexylcinnam aldehyde |
67.5 | 6.75 | 0.0011 | 0.0068 |
| Hydroxycitronellal | 41 | 4.1 | 0.00068 | 0.0041 |
| α-Isomethylionon | 79.5 | 7.95 | 0.0013 | 0.008 |
| Lillial | 22.5 | 2.25 | 0. 00038 | 0.0023 |
| d-Limonene | 41000 | 4100 | 0.68 | 4.1 |
| Linalool | 7600 | 760 | 0.13 | 0.76 |
| Lyral | 21.5 | 2.15 | 0.00036 | 0.0022 |
8.2 Safety assessment of selected fragrances
Normally, a cosmetic product with a margin of safety (MoS) of more than 100 is considered to be a product exposing the user to an acceptable (minimum) safety risk. When calculating the MoS, a safety factor of 10 for extrapolation of data from animals to humans and a safety factor of 10 for particularly sensitive human individuals are taken into account.
Based on the demonstrated NO(A)EL values in the project and previous surveys, a margin of safety (MoS) is calculated for the highest concentrations of fragrance substances found in massage, baby and body oils as well as in mixed essential oils (table 8-3 respectively 8-4). As there are no lower limit when a substance causes allergy, these safety calculations are not based on the critical effect of many fragrance substances: Allergy.
Table 8-3 Safety assessment of the exposure of two persons to 14 fragrance substances found in selected massage and body oils on the Danish market in the spring of 2005 calculated as the margin of safety (MoS)
| Perfumery material | NO(A)EL (mg/kg bw/d) |
Daily dose, adult, 60 kg (SED) (mg/kg bw/d) |
Daily dose, baby, 5 kg, (SED) (mg/kg bw/d) |
MoS[14] (Adult/Baby)[15] |
| Benzyl alkohol | 5 1) * | 0.037 | 0.22 | 135 / 23 |
| Benzyl benzoate | 595 1) | 0.19 | 1.15 | 3130 / 517 |
| Benzyl cinnamate | 500 2) | 0.041 | 0.25 | 12,200 / 2,000 |
| Benzyl salicylat | - | 0.021 | 0.13 | - |
| Cinnamyl alkohol | - | 0.0076 | 0.046 | - |
| Cinnamal | 620 2) | 0.035 | 0.21 | 17,700 / 2,900 |
| Citral | 100 2) | 0.29 | 1.75 | 350 / 50 |
| Citronellol | 50 | 0.077 | 0.46 | 650 / 110 |
| Coumarin | 10 3) | 0.055 | 0.33 | 182 / 30 |
| Eugenol | 79.3 4) | 0.0092 | 0.055 | 8,620 / 1,440 |
| Farnesol | - | 0.023 | 0.14 | - |
| Geraniol | 78.3 4) | 0.21 | 1.25 | 373 / 63 |
| d-Limonene | 250 1) | 1.54 | 9.25 | 162 / 27 |
| Linalool | 50 4) | 1.34 | 8.05 | 40 / 6 |
| 1) Survey of stain removers (14) 2) Chapter 8 3) Survey of hand soap (37) 4) Survey of lip care, (13) * Based on acceptable daily intake (ADI) |
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Table 8-4 Safety evaluation of the exposure of two model persons to 16 fragrances found in selected essential oils on the Danish market in the spring of 2005 calculated as margin of safety (MoS). The safety is assessed for essential oils mixed in basic oil in the proportion 1:10
| Perfumery material | NO(A)EL (mg/kg bw/d) |
Daily dose, adult, 60 kg (SED) (mg/kg bw/d) |
Daily dose, baby, 5 kg, (SED) (mg/kg bw/d) |
MoS (Adult/Baby) |
| Benzyl alkohol | 5 1) * | 0.0023 | 0.014 | 2,174 / 357 |
| Benzyl benzoate | 595 1) | 0.0013 | 0.0080 | > 74,000 (children) |
| Cinnamyl alkohol | - | 0.00023 | 0.0014 | - |
| Cinnamal | 620 2) | 0.00024 | 0.0015 | > 400,00 (children) |
| Citral | 100 2) | 0.54 | 3.3 | 185 / 65 |
| Citronellol | 50 2) | 0.79 | 4.8 | 60 / 10 |
| Eugenol | 79.3 3) | 0.0038 | 0.023 | 20,600 / 3,450 |
| Farnesol | - | 0.0013 | 0.0076 | - |
| Geraniol | 78.3 3) | 0.38 | 2.3 | 206 / 34 |
| Hexylcinnamaldehyde | - | 0.0011 | 0.0068 | - |
| Hydroxycitronellal | - | 0.00068 | 0.0041 | - |
| α-Isomethylionon | - | 0.0013 | 0.008 | - |
| Lillial | - | 0. 00038 | 0.0023 | - |
| d-Limonene | 250 1) | 0.68 | 4.1 | 368 / 61 |
| Linalool | 50 3) | 0.13 | 0.76 | 385 / 66 |
| Lyral | - | 0.00036 | 0.0022 | - |
| 1) Survey of stain removers (10) 2) Chapter 8 3) Survey of hand soap (34) 4) Survey of lip care, (9) * Based on acceptable daily intake (ADI) |
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The calculated margin of safety (MoS) is for several of the found fragrance substances greater than 100, which indicates that the safety risk when applying the product is acceptable.
For other fragrance substances the calculated safety margin is less than 100 indicating that the product may be hazardous to health.. The concentrations of linalool found in massage and body oils for adults are so high that the safety margin is below 100. When essential oils mixed with basic oil are applied, citronellol is seen to cause a safety margin below 100.
The maximum concentrations of fragrance substances are all found in products marketed to adults. There is only a very small probability that these oils are applied to babies, but to be safe, exposure to babies was also assessed. If applied to babies, the substances benzyl alcohol, citral, citronellol, coumarin, geraniol, d-limonene and linalool showed a safety limit below 100. Consequently it is assessed that there may be a health risk for babies if fragranced massage and body oils as well as basic oils mixed with essential oils intended for adults are to be applied to babies.
Two baby oils were tested for content of fragrance substances. The content of d-limonene of one of the products (no. 17) was so high that the safety limit was only 50 compared to the critical effect (liver damages) of d-limonene. d-Limonene was not declared on the product. The other product (no. 18) contained two fragrance substances; both in low concentrations. As only two baby oils were analyses, the number of products is not sufficient to conclude in general that the concentration of fragrance substances in baby oils may be hazardous to health.
Of the mentioned fragrance substances, the safety limit of linalool and citronellol for adults was calculated. Linalool has been assessed previously in the Danish EPA’s survey project (13). The NOEL value for linalool in this project is indicated to be 50 mg/kg bodyweight/day with liver damage as critical effect. Compared to the calculated daily exposure (massage or body oil) a MoS is calculated to be 6 for children and 40 for adults. Linanool is observed to be quickly absorbed through the skin by massage with an oil containing linalool, but is also seen to be excreted again from the body through the urine (13). SCCNFP has listed linalool as a perfumery material causing allergy, but the number of reports referred to about allergy in consumers is limited. 1 and 3 cases of contact allergy from two investigations of 119 and 75 patients respectively have been reported corresponding to 0.8% and 5% of the patients with cosmetics eczema (13).
Citronellol has been assessed in Chapter 7.4 above. A NOEL of >51 mg/kg/bodyweight/day was indicated, which compared with the calculated daily exposure (mixed essential oil) resulted in a MoS of 10 for children and 60 for adults, see table 8-4.
At a NOEL value of d-limonene of 250 mg/kg bodyweight/day by liver damages, a low MoS for d-limonene has been calculated for babies. SCCNFP has listed d-limonene as a perfumery material causing allergy. However, not many cases of allergy in the consumers were reported. 1 and 3 cases of contact dermatitis from two investigations of 119 and 75 patients respectively have been reported corresponding to 0.8% and 5% of patients with cosmetics eczema (13).
In accordance with Danish legislation, Peru balsam is prohibited in cosmetic product (1). This is caused by the fact that many investigations have proved occurrence of allergy in the substance (31). Consequently, we have assessed that the content of Peru balsam in massage-and body oils, irrespective of the amount, is not appropriate, because of the oil being in contact with the skin.
Due to the carcinogenic effect of methyleugenol, SCCNFP has established a limit for the content of methyleugenol in leave-on cosmetic products of 0.0002 weight% (10). Methyleugenol containing 160 mg/kg (0.016 weight%) was found in one of the analysed essential oils. Mixed in a basic oil in a ratio of 1:10, this corresponds to approx. 16 mg/kg (0.0016 weight%). This means that the content of methyleugenol in the product is approx. 8 times above the legal maximum limit for methylgeugenol in leave-on cosmetic products. The content of methyleugenol is therefore assessed to be hazardous to health when contained in the product.
SCCNFP has assessed 26 fragrances as allergens by skin contact. As there is no “zero effect level” for this effect, it is essential to emphasize that persons with perfume allergies or especially sensitive skin should avoid skin contact with these substances (8). There is reason to be aware of the content of perfume in the products since massage and body oils or essential oils for use in self mixed massage oils should are in fact applied to a great area of the skin.
Footnotes
[14] Margin of Safety
[15] Systemic dose of exposure
Version 1.0 October 2006, © Danish Environmental Protection Agency