The media has had a field day just lately, seeing toxic dangers everywhere arising from nasty chemicals in our immediate environment, and blaming them for the hitherto unexplained rise in allergies – as manifested by symptoms of eczema and asthma. To be fair, there is certainly a cause for concern in this area: for example, Melke (2003), referring to Bristol University’s Children of the Nineties study, reveals that nearly one in three children has suffered eczema by the age of three-and-a-half, which is triple the rate in the 1970’s. Part of this media attention is generated by the EU Chemicals Policy, which aims to evaluate all substances which impinge on the environment, and has highlighted chemicals used variously in the home, garden and working spaces. Against this background, the wariness of the Alternative Health Movement towards synthetic chemicals is already legendary, having been previously commented on by Vickers (1995), who contrasts the positive concepts of natural, organic, spiritual, healthy & holistic against those of the synthetic, chemical, unhealthy and mechanistic. Certainly, levels of undesirable chemicals such as those used as flame retardants (like polybrominated diphenyl ethers), insecticides, carpet & upholstery matrix materials, plasticisers (such as alkyl phthalates) etc. are now commonly found in Western homes and in our workplaces, and their long-term persistence in human bodies is cause for enough for health concern.
Fragrances – the new bête noir of environmental pollution?
The finger of suspicion is also pointing at fragrance volatiles – one is tempted to say, raising it to a level of near-paranoia. Pat Thomas (2004) in a recent article in the normally sensible periodical The Ecologist, suggests that there is no difference between conventional perfumes and pollution, saying “fragrance chemicals… include … many other known toxins capable of causing cancer, birth defects, central nervous system disorders and allergic & asthmatic reactions”. It is surprising therefore that those of us who have been employed in perfume factories breathing in these allegedly noxious ingredients at high odour concentrations for much of our working lives, seem to have enjoyed such rude health over the years! Moving swiftly on, Thomas goes on to list “forty-one known (fragrance chemical) ingredients” found in the perfume Eternity Eau de Parfum (Calvin Klein). Thomas suggests that some of these “known” ingredients reproduced below may have dangerous properties, although no actual concentrations of components allegedly contained in the perfume are given. Once the curious non-systematic chemical names in the text are translated, you may recognise one of these “dangerous” ingredients as vanillin, which you might find lurking as a flavouring in the exceedingly toxic local national dish “Crème Anglaise” (or custard as it is alternatively known!).
Benzyl acetate – said to be irritant and also said to be linked to pancreatic cancer.
Benzenemethanol (aka benzyl alcohol) – said to be irritant, CNS disruptor & carcinogen.
Benzeneethanol (aka phenylethyl alcohol) – said to be a CNS disruptor, carcinogen, affects bone marrow etc.
Cyclopentadecanolide – hormone disruptor, irritant, carcinogen.
Eugenol – said to be an irritant, a cause of contact dermatitis, pesticide & insecticide ingredient.
a-Terpineol – said to be highly irritating to mucous membranes and a CNS disruptor.
Benzaldehydehyde, 4-hydroxy-3-methoxy (aka vanillin) – irritant to mouth throat eyes etc…kidney damage, CNS disruption
Of course in the real world, toxic effects of chemicals are directly related to the dose, and splashing 0.03 ml of alcoholic perfume containing minor concentrations of these components behind the ears is unlikely to promote the effects listed above, even in a small minority of extremely susceptible individuals. Further, many of these components identified are identical to those components naturally occurring in the scents emitted from flowers, meadows & pine forests, or are responsible for the odour & taste of spices and natural flavourings etc. – so what are we to do? Mow down all the flowers and trees, since they give off these dangerous volatiles?
Odours from Living flowers and trees
Here are a few examples of the same “toxic” chemical odours listed above in the Calvin Klein perfume, as are given out naturally by living flowers:
Benzyl acetate – in jasmin, narcissus & hyacinth headspace odours and in gardenia oil, ylang ylang oil & cananga oils.
Benzyl alcohol – headspace odour of picked jasmine flowers, narcissus, lily of the valley, hyacinth, honeysuckle, water-lily & meadowsweet.
b-Phenylethyl alcohol – headspace of rose varieties including the yellow tea rose, broom, phlox, & daphne.
Cyclopentadecanolide – found in the scent glands of the musk rat! Other w-macrocyclic lactones are found in forest floor litter and the sun-struck resin of Pinus pinaster (Kaiser 1997).
Eugenol – in the headspace of hyacinth flowers & carnation flowers; and in the oils of clove, cinnamon leaf, pimenta berry, W.I. bay oil, & basil oil CT linalol.
a-Terpineol – in headspace odour of flowers of white freesia, polyanthus, lotus, and in the headspace odour of pine oils & resins.
Benzaldehydehyde, 4-hydroxy-3-methoxy – in vanilla beans, peru balsam, & benzoin resinoid.
So in reality we are continually exposed to emissions of natural materials – for example – as the volatiles from flowers and from leaves. Schenk (1979) has estimated that 438 million tons of monoterpenes evaporate into the air continually from biological material sources – and we are probably the better for it, in terms of the pleasure it gives us!
A Miscellany of Topics regarding Flavourings, Cosmetics,Volatiles and Health.
Attention is also given by the press to synthetic chemicals consumed as flavourings. Corkwise, which we are told is a company of analytical chemists in Surrey, have been finding (added?) pyrazines in South African & New Zealand wines, and theorising over their significance. The same article quoting the above findings (Lawrence 2004) reveals that Michael Fridjhon, a wine critic, has indicated elsewhere in print, that ranges of fake flavourings are used to give characteristic notes to retailed wine, such as blackcurrant flavouring added to Cabernet Sauvignon. Strange that we don’t seem to worry overmuch about any health effects of these unnatural additions to “real” wine. More scary still, (Ravilous 2004) has also run stories on findings of a material in mains water supplies called ptaquiloside, which results from bracken poisoning the water all over the world. Ptaquiloside is capable of causing cancer epidemics. Meanwhile this year also Poppham (2004) reports on the carcinogen methyl eugenol in Ligurian basil leaves used to prepare Italian pesto, the levels of which were alleged to be 600 times over the accepted safety limit (quoting Prof. Francesco Sala of the Umberto Veronese Foundation). Unquantifiable concerns facing aromatherapists regarding methyl eugenol exposure from essential oils used in massage have been discussed recently by the author (Burfield 2004).
A further article alleging health concerns from fragrances was presented by Hilpern (2004), this time in a pull-out supplement of The Independent newspaper, and covered similar ground. A quote from Lindsay McManus of Allergy UK is included, who informed us that ‘second hand scent is more serious than second-hand smoke’. Hilpern points out that Halifax, Nova Scotia discourages the wearing of fragrance in public places, and Santa Cruz, California bans the wearing of fragrance at public meetings – perhaps this restriction will spread? The well-known anti-fragrance campaigner Betty Bridges is also quoted in the article, suggesting that people ask for products which don’t contain fragrances [Betty Bridges had previously published a highly referenced article on health and environmental concerns from fragrances (Bridges 2002) which concluded that there needs to be a system where adverse effects of fragrance chemicals are recorded and evaluated. Bridges also mentions aromachology in the scope of her article].
Cameron (2004) also reports on negative health effects from cosmetics, stating “without exception, modern perfumes are manufactured entirely from petrochemicals”. It is not disclosed however if the author drives a car – petrol production inherently is connected with by-products which need outlets – and fragrance chemicals – many/most of which have undergone rigorous testing procedures – are a socially beneficial outlet for these co-produced materials. Further, lets not forget that if we are looking for bogeymen, the combustion engine has a lot to answer for – particulates & emissions themselves are responsible for high levels of respiratory and other diseases. Cameron quotes the Journal of American Toxicology (no further reference details) on fragrance chemicals penetrating the skin advising: “some (fragrance chemicals) have been shown to cause discolouration of internal organs, others are toxic to the liver & kidneys. Some accumulate in fatty tissue and are passed on in breast milk”….
Whilst I pass on the prospect of bleached kidneys, I’d like to remind readers that the Research Institute for Fragrance Materials is an independent international organisation (established in 1973) which actively investigates the safety of fragrance materials. It has indeed found that one or two fragrance materials such as acetyl ethyl tetramethyl tetralin and musk ambrette are neurotoxic, and the International Fragrance Research Organisation (IFRA) has recommended that these substances be prohibited from use in perfumery under self-regulation. This doesn’t mean that you won’t still find musk ambrette as an ingredient of joss sticks brought back from your holiday to India – but it means that you can check on the full list of IFRA prohibited and restricted materials in perfumes which can be freely viewed at http://www.ifraorg.org/GuideLines.asp. This illustrates the responsible attitude that the fragrance industry takes towards safety, and you, gentle reader, as a member of the public, can ask your supplier of fragranced product whether the fragrance in question is IFRA compliant – although adherence to IFRA regulations is just one of the regulatory safety hoops a marketed perfume will proably need to jump through. It is true that we are learning more about toxicology all the time – after all, less than 100 years ago we used to put copper sulphate in canned peas to make them appear green! Now we can add some safe ghastly green dyestuff instead!
Volatile Organic Carbons.
Hilpern and (separately) Hawkes (2004) covering the same theme on toxic domestic chemicals, refer to a well publicised study, by Alex Farrow et al. (2003) and since as it has attracted so much media attention, we will consider this article in more detail. Farrow looks at the catch-all category of volatile organic carbons (VOC’s), and is concerned with the health of mothers and infants in relation to total exposure to VOC’s (TVOC’s) from household products. To carry this out a large number of medical histories were followed over twelve months, and TVOC’s were determined in 170 home environments of Avon, with the help of the Avon Longitudinal Study of Partents & Children Study Team. It becomes clear fairly early on that the term VOC’s in Farrow’s study refers to propellants in aerosols and solvents in airfreshners, such as toluene, m-xylene, which were assessed by Tenax tubes placed in the subjects living rooms and bedrooms. No distinction is made between solvents and fragrance ingredients, so the class of compounds responsible for the observed symptoms is unclear.
Farrow et al. found that higher airfreshner & aerosol use increased the TVOC concentration, and that infant diarrhoea and earache were significantly associated with airfreshner use; diarrhoea & vomiting were significantly associated with aerosol use. Headache in mothers at 8 months or more past birth was significantly associated with the use of airfreshners & aerosols; maternal depression was significantly associated with the use of airfreshners.
The findings of this relatively small-scale study are quite thought provoking, and appropriate explanations are even more so! Little hard data on VOC’s really exists in the literature. Some papers are reviewed by Farrow et al. on chlorinated solvents and oto-toxicity (oto- meaning ear), and on urinary tract disorders from solvents in mature females seemingly associated with impaired immune system responses. Farrow himself has previously looked at the relationship between nitrogen dioxide levels as an indoor pollutant, and infant gut well-being. It is also intriguing to remember recent findings that babies born by Caesarean section suffer more from infant diarrhoea1 and other conditions that those born normally (perhaps because of the beneficial effects of micro-flora gained via passage down the birth canal) – making it more difficult to establish a base-line for “normal” health. It is also permissible to think about chicken and egg situations – do mothers use more airfreshners & aerosols when diarrhoea and sickness visit the family members, or say, when they are depressed (i.e. the connection is non-causative)? Most of all the connection between sickness and VOC’s as fragrance – which can include essential oils and absolutes, just as much as fragrance chemicals – is not firmly made here.
A culture of fear (of terrorism) is currently being used both sides of the pond for political ends, but the axis of evil doesn’t necessarily extend to the collection of fragranced cosmetics on your bedroom dresser. Certainly many bad things are currently being laid at the door of household and home-care products, cosmetics and fragrances, including allegations of many minor illnesses and allergies. Phobias about synthetic fragrances are being pandered to by the media, who are obligingly providing plenty of scary, and often inaccurate, material. It isn’t a great step to include the volatiles from essential oils and flowers as unwanted VOC’s, which can invade the personal space of these sensitive chemophobic individuals, and which may provoke illness & distress, either real or imaginary….
My take on this is that VOC’s cannot be lumped together as a group as Farrow et al. has done, and proclaimed harmful per se. It is far more likely that specific toxic components (chlorinated solvents, aromatics like benzene) are the causative agents, and that fragrance components are being tarred with the same brush. In the case of fragrance phobia, the power of auto-suggestion is such, that a negative image of synthetics to some suggestible individuals people may “bring on” imagined symptoms.
As regards any inferences for aromatherapists from these reports, we can be assured that the safety of essential oils is a relatively well-studied subject. Whilst toxicological inhalation data on individual essential oils is admittedly sparse, topics like skin sensitivity and reproductive toxicity have been the subject of many studies, many of which are on-going. Further we have a fragrance industry which has been producing essential oils and absolutes for more than 140 years, and as mentioned previously, whose workers haven’t experienced serious occupational health problems like those found in mining, cotton and asbestos industries, in spite of the high levels of exposure to fragrance volatiles. The problem then is often more that those concerned with safety legislation matters in the EU, or at National Government level are not well versed in finding reference information – and so we get strange decisions like the suspension of the free use of citronella oil in retailed insect repellents in Canada on the basis of lack of toxicological data (!) The problem is arguably not one of lack of appropriate information, but leading the horse to the right trough!
First Published 04/06/2010