BHT and BHA
BHT (butylhydroxytoluol) and BHA (butylhydroxyanisol) are still classified among a number of lipophilic (oily) raw materials as antioxidants which prevent substances from becoming rancid. The German consumer magazine Öko-Test published the following information on BHT and BHA: “In the course of animal experiments, changes to the immune system, blood count, thyroid and liver were recorded. Both substances spread through human tissue and reach the foetus. They are recognised as being allergenic. Because BHA and BHT can easily be replaced by the natural antioxidant tocopherol (vitamin E), there is no reason to continue to use them.

Halogenated organic compounds
Most preservatives are halogenated substances. This means that chlorine, bromine or iodine are attached to the molecule at some point. If halogens are found in the chemical analysis of a product, it can be assumed that they stem from the synthetic preservative. Organic halogen compounds also occur in nature. This does not mean that they are unproblematic, however. Halogenised materials have a considerable allergy potential, they are reactive and, if they enter the tissue, they can decompose, accumulate and cause damage.

Formaldehyde and formaldehyde releasers
Formaldehyde: in June 2004, IACR (International Agency for Cancer Research) declared that 26 scientists from 10 countries had reached the conclusion that formaldehyde is carcinogenic for humans. In June 2006, the German federal institute for risk evaluation announced that the “carcinogenic effect of inhaled formaldehyde had been sufficiently proven”. The response to this was to ban the use of formaldehyde from aerosols (sprays). Formaldehyde is authorised for use in oral hygiene products in proportions of up to 0.10% (1,000 ppm) and in other cosmetic products up to 0.20% (2,000 ppm). Formaldehyde is still indispensible for the industry in conventional nail hardeners as there is no substance available to replace it in this context. The German IKW (industrial association for personal hygiene and cleaning agents) is alarmed and is preparing its members for the possible reclassification of formaldehyde in chemicals legislation. In June 2006, the association declared: “If chemicals legislation confirms the classification of category 1 or category 2 carcinogens, formaldehyde will be formally prohibited for use in cosmetics. It was clear to us from the presentations that the authorities are prepared to make a distinction between formaldehyde and formaldehyde releasers which would mean that releasers would probably not be directly affected by regulations concerning formaldehyde.”
Formaldehyde releasers: formaldehyde releasers, such as DMDM hydantoin for example, have emerged as replacement substances for formaldehyde. They release formaldehyde under specific conditions, e.g. when in contact for long periods with water. Formaldehyde releasers are used as preservatives in all kinds of cosmetic products.
This raises the question as to whether or not they should be treated in the same way as pure formaldehyde. The releasing of formaldehyde also occurs in nature. In stored fish, for example, formaldehyde originates from the enzymatic separation of the trimethylamine oxide in the fish. In certain vegetables, such as tomatoes, cauliflower, green onions and spinach, the formaldehyde content is between 3 and 60 ppm. What conclusions are we to draw from this information? A considerable amount of data is available concerning the dangers of formaldehyde. Assertions about the harmlessness of formaldehyde derived from formaldehyde releasers are generally based on deductions and assumptions. When they purchase a product preserved with formaldehyde releasers, consumers never know how much formaldehyde it contains. Not all formaldehyde releasers release exactly the same amount of formaldehyde. One may release little and others more. Cigarette smoke, for example, releases formaldehyde in quantities of between 57 and 115 ppm. Non-smoker protection exists to ensure that other people do not breathe in this smoke and health risks are highlighted on cigarette packets. By comparison, formaldehyde is authorised up to 1,000 ppm in oral hygiene products, which can easily be swallowed, and up to 2,000 ppm in other cosmetic products.
In view of the information available on pure formaldehyde, blanket evaluations such as "formaldehyde releasers are harmless" are unjustifiable. Is the dose contained in a cosmetic product really kept to a minimum (on a par with that contained in certain food products)? Or is it higher? The consumer does not know the quantity of formaldehyde involved.

Nitrosamines
When substances react with one another and nitrosamines are formed (for example in barbecues when fat comes into contact with the charcoal), a dangerous, potentially carcinogenic chain is created. Nitrosamines can be produced in cosmetic products when, for example, triethanolamine and certain nitrosating preservatives are used at the same time. Individual raw materials can also be polluted by nitrosamines. Because of the danger of nitrosamines, cosmetics should not contain ingredients which present a risk of nitrosamine formation. For this reason alone, the decision to refrain from using halogenated substances and preservatives is a further step towards consumer safety.

Synthetic sunscreens
Only a certain number of substances are authorised according to the Cosmetics Directive and maximum quantities are prescribed for each one. In the case of certain sunscreens, e.g. oxybenzone, it is not sufficient to list them in the INCI declaration. It is necessary to provide additional warning information, e.g. “Contains oxybenzone”. Numerous sunscreens present considerable potential problems as the filtering function is dependent on molecules absorbing a specific wavelength range. This is not without consequences: the molecules are altered. New molecular compounds may be formed which are highly allergenic or create phototoxic reactions and thus become unstable due to light or enzymes in the skin. An example of this is octyldimethyl PABA. This sunscreen was used for many years before being banned in 2007.
Death of coral due to sunscreens: in 2003 Margret Schlumpf, W. Lichtensteiger and H. Frei (Hrsg.) presented extensive investigations of the effects of the large-scale use of synthetic sunscreens in their book entitled “Kosmetika, Wirkungen und Umweltverhalten von synthetischen Parfümstoffen und UV-Filtern” (“Cosmetics, effects and environmental behaviour of synthetic perfume materials and UV filters”) (published by Kind und Umwelt, 2003). According to this work, we are dually exposed via the skin and via the food chain, “As these generally fat-friendly compounds accumulate in foods containing fat, e.g. fish and human milk.” The frightening scale of damage is described in new investigations by marine biologists which were presented to the public at the beginning of 2008. Scientists from the polytechnic university in Ancona, Italy, reached a clear conclusion: sun creams containing synthetic sunscreens pose a threat to coral reefs worldwide. The impetus for investigations into the effects of sunscreens was provided by observations in Mexico: a high level of mortality was recorded among all life forms in the sea enclosed by the Yucatan Peninsular, which is highly frequented by holidaymakers. The results are alarming and indicate that just 10 microlitres of sun cream in a litre of sea-water cause coral to lose its colour completely and turn pale within only four days. Particular problems are posed by the chemical sunscreens ethylhexyl methoxycinnamate, benzophenone 3 and 4 and methylbenzylidene camphor. These are all sunscreens which are also under suspicion due to their hormonal effects. The final conclusion drawn by the scientists was that sunscreens contribute to a large extent worldwide to the destruction of this important and wonderful ecosystem.

Cosmetic raw materials which are harmful to the environment
The question is raised as to whether cosmetic ingredients which are “only” detrimental to the environment are less problematic than those which are classified as being harmful and dangerous to health. The answer is no, because the effects of environmental damage also present a threat to animals and humans. Substances which are not degradable in purification plants or which are directly discharged into the natural environment are in a category apart. The route that they follow and the effects they produce are largely unknown. They may, for example, enter the drinking-water network and affect humans as a result. They may also be consumed by animals (e.g. fish) and subsequently by humans as part of the food chain. These incalculable factors are among the elements that contribute to growing scepticism about non-biodegradable substances.

EDTA
EDTA (ethylene-diamino-tetra-acetate) was and still is extremely popular because it is a good complexing agent. However, EDTA, like its substitute editronic acid, accumulates and is not degradable. This is due to the interactions of EDTA with heavy metals, hardness components and micronutrients. Because EDTA is not degradable in water treatment plants, it enters the watercourses together with the heavy metals to which it is bound. As EDTA is already present in waste water (purification plants) as a heavy metal complex, it is not degradable in the natural watercourses either. However, EDTA-iron complexes are degradable in surface water through exposure to light. This leads to the formation of decomposition products which present unknown and possibly significant environmental risks. EDTA also promotes or restricts algae formation in the watercourses and can enter the drinking-water system as is cannot be blocked by activated-carbon filters. The risks presented to humans by drinking water containing EDTA-heavy-metal complexes have been investigated as little as many other consequences of environmental damage. EDTA can be identified in the INCI declaration by the letters EDTA generally in associated with another word such as tetrasodium EDTA. It is scandalous that EDTA is still being used as it should be replaced without hesitation. A natural alterative to EDTA could, for example, be the phytic acid obtained from rice husks. The German cosmetics industry promised years ago to abandon EDTA but so little has been done that even the industry association has appealed urgently to its members to follow up this promise.

VOC
VOC stands for volatile organic compounds. The environmental damage caused by humans using VOC has risen sharply over recent years, e.g. due to traffic or construction chemicals such as paints and adhesives. A number of the many VOC are classified as being highly toxic and carcinogenic while others, such as ethanol used in cosmetics, are harmless.

Quats and polyquats
The traditional quats are CTAC (cetyl trimethyl ammonium chloride) and DSDMAC (quaternium 5). All simple quats are not biodegradable and generally produce an irritating effect on the skin. This is also true of polyquats (polyquaternium plus a number). These are complex compounds with quaternary ammonium salts as their central molecules. These polyquats are used because polycations generally adhere better to the surface of the hair than simple cations. They often contain natural components such as polyquaternium 4 or 10, both of which are complex compounds with the natural component of cellulose. The natural parts are generally biodegradable but the central molecule is not. Quats (quaternary ammonium compounds; INCI: quaternium plus a number) are used as antistatic agents in hair-care products in order to prevent the formation of static electricity in the hair, making it easier to comb.

Silicones
Experts are unable to agree whether or not silicones are degradable or whether they accumulate in the environment. The arguments put forward by defenders of silicones are not convincing. It has been suggested that silicones that enter water treatment plants evaporate or adhere to small particles in the water to end up in the sewage sludge. The latter is burnt, deposited or spread on fields. Even though it may be true that the evaporation of silicones and the burning of sewage sludge containing silicones does not influence the greenhouse effect, the consequences of the large-scale use of silicones are unclear. How does it affect the soil? Silicones are only degradable in the earth if the ground is dry. If it is damp for long periods, no decomposition takes place. In regions without any water treatment plants (most regions of the world!), they enter the sea or the rivers where they are not degradable. The problems which this poses to the natural environment, animals and humans cannot yet be predicted.

Acrylate
Shampoos and creams must not be runny. Bulking agents are used to ensure that a cosmetic product flows just as we expect. Natural substances such as alginic acid, starch or mineral bentonite could be used but the traditional cosmetics industry tends to use acrylate which is damaging to the environment. Natural bulking agents, if they are used in too high doses in a cream, can have the disadvantage of forming a visible film on the skin. Acrylates, however, are not noticeable. Yet they can block the skin’s pores.

Synthetic musk compounds
Synthetic musk compounds are among the chemicals that have been in the crossfire of criticism for many years. Pure musk is a natural product and the scent with which musk deer entice females during the mating season. This fragrant mating call has also allured the senses of perfume creators. Deer have to surrender their lives for the production of musk. For the protection of animals and species, natural musk should therefore not be used. The perfume industry has proposed numerous aromatic nitromusk compounds as substitutes, such as musk xylol, musk ambrette, musk ketone, musk mosken and polycyclic musk compounds such as galaxolid, cashmeran and celestolid. However, alarming data has been available for a number of years relating to these substitutes which shows that at least some of the artificial fragrances enter the tissue due to their high “bioaccumulation potential”.
• Musk xylol has been detected in breast milk and, in experiments conducted on rats, caused damage to the nervous system as well as abnormal changes to the testes in male rats.
• After years of debates about the risk evaluation of musk fragrances, it has been decided that musk ambrette, musk mosken and musk tibeten should not longer be used in cosmetics.
• Limiting values have been introduced for musk xylol and musk ketone in cosmetics. The musk issue is still very much a subject of discussion. Many questions remain open including that of the long-term effects of musk compounds. The effects on young children who are exposed to synthetic musk compounds through breast milk have not yet been investigated at all.