Old lavender oil - the dangers

Old lavender oil may be a problem.

By Martin Watt.

In Sept 2003 I obtained some papers on aged linalool and lavender oil which
are rather alarming. For years I have been advising therapists not to use old
citrus peel or pine family oils on the skin. This is because as those oils age with
oxygen exposure, they form chemicals which can initiate sensitisation. It now
seems that lavender oil and any oils high in linalool need to be treated with
similar caution.

There was an alarming increase in the incidence of sensitisation reactions to
lavender products in Japan. While in 1990 the reaction rate was 1.1%, in 1998
this had climbed to 13.9% of skin patch tested patients. I hasten to add here
that they used a 20% solution of lavender oil to ascertain results - high
compared with normal aromatherapy use. The authors of this report also found
a high reaction rate to dried lavender flowers. They attributed the rise in
reaction rates to the increasing popular use of aromatherapy and related
products in Japan. They did not think the use of fragrances in regular cosmetic
products was the cause. Mariko Suugiura et al. 2000. Contact Dermatitis, 43,

The next two reports - giving credibility to the above - are on the chemicals
created as linalool ages. It has been found that linalool hydroperoxide
increases as the linalool decays. This is important because the rate of chemical
decay is rapid compared to the potential shelf life and age of oils used in

1) When linalool was oxidised for just 10 weeks the linalool content fell to 80%
and the remaining 20% consisted of a range of breakdown chemicals. These
were isolated and tested and linalool hydroperoxide was confirmed to be a
sensitising agent. Interestingly, the fresh linalool was not a sensitiser which
kind of blows a hole in our crazy European labelling regulations. Maria Skold et
al. 2002. Contact Dermatitis, 46, 267-272.

2) In this separate research they investigated the sensitising activity of
linalool. This was a commercial grade of 97% purity (see other articles on this
site over that). Included in the impurities was linalool hydroperoxide. The
sample of commercial linalool was then purified and tested. The only reaction
from the purified linalool was when it was used at 100%. They found a
dramatic reduction in sensitisation occurred when the linalool was 98.6% pure
and the dihydolinalool was below 1.4%. In this paper it was considered that
some of the other oxidisation chemicals may also have sensitisation potential
but the finger of suspicion points to linalool hydroperoxide as the main
culprit. Finally, this paper reports that this work has implications on the storage
and shelf life of fragrance ingredients such as linalool. Basketter D. Et al. 2002.
Contact Dermatitis, 46, 161-164.
So to practicalities, what can we do about this?

1. Beware of buying oils that may be months old or badly stored before you
get them. Obviously the further back you can get in the chain of supply the
better, although that is not easy in aromatherapy.

2. The big oil traders say they are experimenting with lab test strips which will
detect if an oil has a lot of peroxides in it. That should prevent an oil which is
already badly oxidised from reaching aromatherapy suppliers.

3. Add lavender; petigrain; neroli; rosewood; ho leaf; mentha citrata and any
other high linalool content oils to those not to be used on the skin once they
are over about 6 months old and/or have had a lot of air in the bottle.

4. Store all your oils that are not in daily use in your refrigerator in an airtight
box. That alone will considerably delay oxidisation.

Another important issue related to the above:
This research found that vegetable fats/oils seem to prevent irritant contact
dermatitis. Schliemann-Willers S. Et al. 2002. Contact Dermatitis, 46, 6-12.
They found that a range of vegetable oils such as palm; coconut; sunflower;
rape seed, etc. provided significant protection to the skin from irritating
substances. Most people who know me will acknowledge that I think
fractionated coconut oil is the best thing since sliced bread, but this report
confirms how good it really is. Their research was targeted at finding suitable
barrier creams for protecting workers in the food handling trade, but this has
implications for aromatherapists and masseurs.

A cream made using these fixed oils may help protect therapists hands from
the essential oils you use. Such vital investigations on the protection of
therapists should be undertaken by the aromatherapy associations. However,
as their leaders are only interested in meetings with incompetent Government
officials, setting phoney trade standards, validating crap courses and
organising joke conferences, such important safety issues are left out in the
The need for antioxidants.
The above information on the dangers posed by oxidised oils, is more evidence
that the use of antioxidants in essential oils is critical to making them safe over
protracted time periods. Personally I am in favour of this as in my opinion
these chemicals are not going to cause many problems, but will prevent skin
reactions from oxidised oils. Of course added antioxidants should be declared
by the producers/suppliers, but as the aromatherapy distribution trade has
always operated on hype and lies I know they will not be declared.

I am aware that there has been some heated discussion on some
aromatherapy newsgroups about the issue of adding anything to pure essential
oils. However, what has not been touched on is that some producers and large
distributors have been adding antioxidants to certain oils for years. So there is
nothing new in this practice, but since most aromatherapy distributors are so
remote from the *real* essential oil trade, they are simply not aware of such
common trade practises.

People must understand that aromatherapy suppliers are NOT the big traders
in essential oils and never have been. They are tiny fish in a huge International
trade. This is even more reason to add antioxidants to oils. I have personally
witnessed cottage industry aromatherapy suppliers who have had old oils in
stock way beyond their use by date. Their small scale financial turnover does
not allow them to throw these oils out. Yet it is in America (where small kitchen
sink suppliers are more common) that they are kicking against the
preservation of oils.

The whole concept of their arguments is fundamentally flawed. "I do not want
to add anything to a pure oil" is the commonest heard. Yet these people do not
even understand what the criteria is of determining the purity of an essential
oil. The fact is that as soon as an essential oil is distilled it is no longer "pure".
Distillation creates chemicals not occurring in the plant and destroys others. All
essential oils (except perhaps those that have been rectified) will contain
traces of the natural contaminants in the plants surrounding. So a local lizard
has peed on the rosemary; insects have nibbled it and left behind their dung;
the donkey carrying the bales has peed on the materials; some pesticides from
the local farmer spraying his wheat have drifted onto the field of "OG"
lavender; the soil has had sewerage sludge added as a fertiliser; radiation from
Chernobyl has fallen on the area; the groundwater is contaminated with a
variety of chemicals as is common. So what the heck is a "pure essential oil"?

So rather than have food grade antioxidants added to ensure the safety of
certain oils, these people would rather risk their customers health on the basis
of some uninformed philosophies.

Source and copyright: aromamedical.org
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