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Survey of lip care products with fragrance and flavour

7 Oils and fats

• 7.1 Oils and fats
• 7.2 Mineral-based oil and fats
  • 7.2.1 Mineral-based oils and fats in lip care products
  • 7.2.2 Investigation of the hydrocarbon composition
  • 7.2.3 Assessment of the safety

7.1 Oils and fats

The products' declarations of contents show that the purchased products contain both natural and synthetic waxes and oils, cf. table 7.1. From table 7.1 it appears that the most common oils and fats in lip care products are beeswax, castor oil, vaseline/petrolatum and the wax types candelila wax, carnauba wax, and microcrystalline wax. These substances are often the main ingredients in lip care products. Also synthetic polymers are used often, particularly polybutene is seen as main ingredient in lip care products but also polydecene and polyisobutene

The various oils and fats have many different technical properties such as viscosity-improving or emulsifying properties. Many lip care products contain several oils and fats, both mineral and plant-based, to obtain the wanted technical properties. Among these castor oil that gives sheen and a good distribution of the pigments is pointed out (4). The use of wax, e.g. beeswax and carnauba wax, gives hardness and sheen to products in sticks and increases the products' melting point (4). Beeswax stays on the lips for a long time and prevents cracking of the product. Synthetic polymers increase the product viscosity depending on their molecular weight.

Fossil wax such as Ozokerite and Ceresin, extracted from coal and slate clay, paraffin wax and microcrystalline wax, extracted from petroleum, and synthetic wax are also used in lip care products and increases the products' strength. Among these Ozokerite and Ceresin absorb oil well and prevent crystallization (10). Paraffin wax, which has a crystalline structure different from microcrystalline wax (11), mixes badly with castor oil (4), which may be why it is not often used in lip care products cf. table 7.1.

Triglycerides are also used in many lip care products. Vegetable oils are primarily composed of triglycerides. Chemically, triglycerides are composed of three fatty acids varying in chain length and number of double linkings, i.e. the content of unsaturated fatty acids, depending on the seed or fruit from which the oils are extracted (12). This results in a large variation of the technical properties of the substances. When using unsaturated vegetable fatty acids it is important to notice that they may go rancid (4), therefore antioxidants are often added.

In addition to the above oils and fats many of the products contain fatty acid esters. This group includes different esters, e.g. stearates, palmitates, acetates, malates, myristates, etc. The substances are not real oils or fats but have various technical properties close to oils and fats. Esters may be added as solvents or viscosity-improving substances and often have an emollient effect (4). Myristyl myristate improves application and has an emollient effect, and isopropyl myristate makes the product less sticky (10).

Octyldodecanole is an aliphatic saturated fatty alcohol with a chain length of 20 carbon atoms used in several of the lip care products. Octyldodecanole spreads easily on the skin and does not leave a greasy look. The substance may be used as a dispersing agent for pigments and as an emollient. It mixes well with wax and other fatty substances (13).

Silicone oil is a common name for organic polymers. Silicone oil is found in 7 of the purchased products. Silicone oil may have fatlike properties but is usually not characterized as a fatty substance (4).

Table 7.1. Most frequently used oil and fats in lip care products.

When grouping the oils and fats in table 7.1 in hydrocarbon-based/mineral oil-based fats and in vegetable/animal fats, it can be seen that most of the purchased lip care products contain vegetable-based or animal-based fats, oils or waxes, cf. table 7.2 and 7.3 below. From table 7.2 it appears that hydrocarbon-based/mineral oil-based fats have been used 169 times in lip care products. Vegetable-based or animal-based oils and fats seem to be more popular, cf. table 7.3, as they have been used 338 times. Only the frequency of use of the oils and fats has been assessed, as there is no information on the amount of the different oils and fats in the various products.

Table 7.2. Mineral-based oils and fats in lip care products.

Table 7.3. Vegetable-based/animal-based oils and fats in lip care products.

7.2 Mineral-based oil and fats

Mineral paraffin is used in many lip care products and other cosmetics and is also a common ingredient in foodstuffs (11). The German Bundesamt für Gesundheit and the Swiss Stiftung zur Förderung des Stillens recommend that paraffin and vaseline should not be used in breast care products (14). As a result, the Danish Environmental Protection Agency wanted an investigation of the distribution of hydrocarbon in the mineral-based oils and fast in the purchased lip care products in order to evaluate a possible influence on the safety when using these products.

A Swiss study showing that mineral paraffin can be detected in breast milk is the basis for the above recommendation. The study comprised 33 breast milk samples in which mineral C_15-45 paraffin were found in concentrations of an average of 95 ± 215 mg/kg fat and a maximum of 1300 mg/kg fat. The average paraffin chain length was between C₂₃ and C₃₃. In 1995, the EU Scientific Committee for Food (SCF) determined a provisional acceptable daily dose (t-ADI) of 0-4 mg/kg body weight for C₃₄-paraffin (15) (16). Generally, it is assumed that paraffin with a carbon chain length above C₂₉ is not absorbed in significant amounts (17). When estimating worst-case doses the content of mineral paraffin in breast milk fat is estimated at 200 mg/kg. Babies of 5 kg consuming 800 g milk/day with a fat content of 3% consume 24 g fat/day. This means that the babies consume approx. 1 mg/kg/day. This complies with the ADI determined by SCF, however, with the reservation that this study has proved mineral paraffin with a shorter carbon chain. It is believed that paraffin with a chain length above C₁₀ do not easily penetrate the stratum corneum, but this study indicates that even high molecular paraffin may be absorbed by breast skin. Consequently, the conclusion of this study is that high molecular paraffin are probably not suitable for use in nipple salves (17).

7.2.1 Mineral-based oils and fats in lip care products

The mineral-based oils and fats were identified based on the products' INCI declarations of contents and inquiries were made to the producers concerned. Consequently, this survey does not include chemical analysis of the used mineral oils and fats. The evaluation is based solely on voluntary participation of the producers and their information.

Prior to the inquiry to the producers, the following three mineral oils and fats were identified in the purchased lip care products:

• Paraffin (9 products)
• Paraffinum Liquidum (19 products)
• Petrolatum (33 products)

The mineral-based oils and fats were found in 43 of the purchased lip care products and in several cases they were mixed with vegetable oils and fats. Inquiries were made in the relevant language (Danish, English or Spanish) to 16 different producers. If a Danish importer was identified in connection with the inquiry to the producers, an inquiry was also made to the Danish importer.

Information on mineral oils and fats was received from 10 producers. One producer reported that the product in question was no longer part of their Danish range and that products for sale in the shops are a surplus stock. Six producers did not participate in the survey; three producers with a Danish address; two with an address in the EU, and one in the USA.

It is clear from the material from the 10 different producers that some producers use the same raw materials for several products in their product range and that several producers use the same raw materials supplier. The information received on the used mineral-based oils and fats covers 33 of the purchased 43 products.

Safety data sheets or extracts from safety data sheets were received for all mineral oils and fats.

7.2.2 Investigation of the hydrocarbon composition

Paraffinum Liquidum, mineral oil

Information was received on four different qualities of mineral oil from five producers/importers, all stating CAS no. 8042-47-5 as for white mineral oils. These oils are estimated neither to be carcinogenic, mutagenic nor genotoxic and are not covered by the regulations concerning CMR substances. The used white mineral paraffin oils are all of pharmaceutical quality. Generally, Paraffinum Liquidum consists primarily of two types of saturated hydrocarbons: the paraffin ones (often the branched hydrocarbon chains) and the naphthene ones (cycloalkanes), and the majority has a hydrocarbon chain length of C₁₆ – 22 (4). A chain length of C₂₀ after 5% distillation is reported for one of the used oils and the remaining oils are assumed to have a similar hydrocarbon composition. As a result, the used mineral oils are not comprised by SCF's ADI, which concerns mineral paraffin with a longer hydrocarbon chain length.

Petrolatum

Information was submitted on six different petrolatum raw materials with CAS no. 8009-03-8. Petrolatum is covered by the regulations on CMR substances unless it can be proved that the substance from which it is made is not carcinogenic. There is no immediate information on this or on the hydrocarbon composition in the received safety data sheets or information on the petrolatum, however, it appears that petrolatum is not classified as hazardous according to the regulations on chemical substances and products (18). Three of the petrolatums were the white type, three the yellow type. Generally, petrolatum like mineral oil consists of two types of saturated hydrocarbons: the paraffin ones and the naphthene. The distribution of hydrocarbons depends on the oil from which the petrolatum is derived and the method used for isolating petrolatum from the oil. The hydrocarbon chain length in petrolatum is between C₁₇ and C₅₁, the majority of the hydrocarbons with a chain length of C₂₈ (12).

Paraffin (wax)

Information is received on three different paraffin wax with CAS nos. 64742-51-4 and 8002-74-2. These are estimated neither to be carcinogenic, mutagenic nor genotoxic and are not covered by the regulations concerning CMR substances. The hydrocarbon composition of the paraffin wax was not stated in the received safety data sheets. Generally, paraffin consists of two types of saturated hydrocarbons: the paraffin ones and the naphthene. Just as petrolatum the distribution of hydrocarbons depends on the oil from which the wax is derived and the method used for isolating wax from the oil. The hydrocarbon chain length in paraffin wax is between C₁₈ - C₃₆ (11).

7.2.3 Assessment of the safety

As mentioned above, the EU Scientific Committee for Food (SCF) assessed mineral and synthetic hydrocarbons in 1995 and determined a provisional acceptable daily dose (t-ADI) of 0-4 mg/kg body weight for white paraffin oils with a hydrocarbon chain length larger than 25 at 5% distillation. ADI for paraffin wax is determined at 0-20 mg/kg body weight (16).

If ADI for white paraffin oils is taken as a guide for a worst-case scenario of oral consumption as the only exposure channel of the used mineral oils and fats, the following can be calculated:

Highest recommended daily exposure (ADI), mineral oil, child:
18 x 4 mg/kg = 72 mg

Highest recommended daily exposure (ADI), mineral oil, woman:
60 x 4 mg/kg = 240 mg

As can be seen, ADI for children is of the same size as the consumption of lip care products per day, but even if the product should consist solely of mineral oil, which will not occur in practice, ADI would still be observed. ADI for adults will not be exceeded, as application of 240 mg is 4 times higher than the daily amount of lip care products even if the lip care product should be made of pure mineral oil.

Based on the above and based on other data from literature (11) it is assessed that the used mineral oils and fats are not hazardous to health when used in lip care products.

It was not possible in this survey to obtain an accurate picture of the hydrocarbon composition of the mineral-based oils and fats in the purchased lip care products.

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Version 1.0 March 2006, © Danish Environmental Protection Agency