Asthma UK community forum

Oilseed Rape Discussions

The research paper titled 'The precautionary approach to oilseed rape allergy"" presented in 1994 was written by a lay-person with no medical, environmental or scientific training or experience.

The paper appears to have stood the test of time as to date, no scientific evidence has been published in the learned journals to confirm that oilseed rape is not responsible for causing widespread asthma/allergy symptoms in those who live in close proximity to rape fields.

Take hair (as he throws bright yellow wig in the corner)


11 Replies

Current Position / Status

Current position of the European Commission

Official Journal C 078 E 27/03/2004 P. 0688 – 0688

Written Question (by Graham Watson, MEP)

Is the Commission aware of any research into the effects on human health of oilseed rape cultivation - especially where it is grown in proximity to habitation?

Are there any plans to control the planting of this crop within close proximity of human habitation?

Written Answer (by Commission)

Similar written questions were put to the Commission in 1991, 1992 and again in 1996. The Commission is not aware of a consensus within the scientific community on the matter raised in the Honourable Member's question. The Commission knows that there is some concern about the possible links between allergic symptoms in humans and the crop of oilseed rape and can confirm that several studies have been carried out on this subject, in particular by the Scottish Crops Research Institute and the University of Dundee [*]. Given the result of the published papers, no conclusive evidence is available to demonstrate a direct cause effect on human health from oilseed rape cultivation.

* McEvan M, Macfarlane Smith WH. Identification of volatile organic compounds emitted in the field by oilseed rape over the growing season. Cli Exp Allergy. 1998; 28: 332-38.

* Parratt D, Macfarlane Smith WH, Thomson G, Cameron LA, Butcher RD. Evidence that oilseed rape causes respiratory illness in rural dwellers; Sco Med J. 1995; 40: 074-76.


Macfarlane Smith (1998)

Identification of volatile organic compounds emitted in the field by oilseed rape over the growing season.

McEvan M, Macfarlane Smith WH.. Cli Exp Allergy. 1998; 28: 332-38.


BACKGROUND: Oilseed rape has been associated by rural dwellers with seasonal symptoms, such as sneezing, coughing, headache and eye irritation, during its flowering season, for a number of years. This study was performed to identify the volatile chemicals emitted from oilseed rape in the field.

OBJECTIVE: The objective of this study was to establish which volatile chemicals may be causative factors of oilseed rape allergy/toxicity.

RESULTS: The major constituents identified were the monoterpenes limonene, sabinene, beta-myrcene, and cis-3-hexen-l-ol acetate, a 'green leaf' volatile. The minor constituents included monoterpenes, sesquiterpenes, short chain aldehydes and ketones, other 'green leaf' volatiles and organic sulphides including the respiratory irritant, dimethyl disulphide.

CONCLUSIONS: This report highlights the diversity of volatile chemicals emitted by oilseed rape and confirms field emissions to be broadly similar to those found previously in laboratory studies.


Parratt (1995)

Evidence that oilseed rape causes respiratory illness in rural dwellers

Parratt D, Macfarlane Smith WH, Thomson G, Cameron LA, Butcher RD. Sco Med J. 1995; 40: 074-76.

[Extract from paper]

...We believe that this study has clearly demonstrated that oilseed rape induces symptoms in a significant proportion of otherwise healthy individuals. However, we do not know the cause of these symptoms. We have examined pollen, plant fungi, agrochemicals and volatile chemicals emitted from the crop, all of which may play a part in causing symptoms, but as yet there is no clear evidence that these are the inducers.


Macfarlane Smith (1994)

The identification of potential aerollergens/irritants from oilseed rape: volatile organic compounds emitted during flowering progression.

Butcher RD, Macfarlane Smith WH. Cli Exp Allergy. 1994; 24: 1105-1114

[Extract from paper]

…From the work we have identified a number of volatile compounds emitted from intact growing oilseed rape plants and have indicated those that appear to be specific to, or increased over the flowering period of this crop. We found only minor differences between the six cultivars of oilseed rape which we investigated. This suggests that if the volatiles are involved in an allergic or irritant response in humans then the exposure to the volatiles could be expected to be the same now as when the crop first began to become more common. Secondly, since the spring sown cultivars also showed that similar volatiles were emitted, then the latest agricultural trends towards increased acreage of this crop, which flowers at a later time than autumn sown crop, will result in an increased period over which public exposure could occur (April-July). However, the possible role of the identified volatile compounds in the link between oilseed rape and respiratory mucosa and conjunctiva irritation is at present unclear but their identification represents an important step in future work to define their allergenic or irritant potential.


Wow, the wig cogs have deffinately wirling away today!

Thanks Deek! Very interesting.

Are you still wearing a bright yellow wig?

Take care




Hi Kate LOL,

No, I'm not wearing bright yellow wig tonight. I think I may have got a bee in ma wig, or something - LOL.

This thread is not about ""bright yellow wig wearers"" like me. Its for anyone who wants to know more about the alleged health problems associated with rape fields, otherwise known as the yellow peril. Perhaps some campers may want to say that their asthma is not really affected by oilseed rape. All discussions/ questions welcome.

Take hair,



Hi Deek,

I am going with the theory that the VOCs etc from rape cause a synergistic effect with all the tree pollen that is around at the moment. I am allergic to tree pollen ( Birch I think but may also be the whomping willow in my road) so I am sneezy itchy, chesty at the mo.

Mum says it gets to her sinuses and hurts her eyes and she is a healthy person usually.

Strange that in France no one bats an eye lid ( or a tear!) about it all - perhaps all the hype has a similar effect of mass hysteria type events ( eg 40 school girls all fainting and throwing up after one starts being ill but no obvious cause)

Anyway, seems a very complicated issue!



PS please pass wig bee this way - I will give bee a home!


Ohhh Kate, you have sent ma wig wirling again LOL

I will see if I can post later re - tree pollen & synergistic effect. I think I've got an article from the New Scientist on a similar theory, its a bit dated but well worth a wee read.

Re - bees (oh you have got the bees buzzing also, LOL) I am sure you will be aware that the wild bee population is in serious decline. Well I have a theory on this also.

In the words of Phil Colins (tongue in cheek) ""I can smell it coming in the air tonight""

Take hair,



Morning Kate,

Synergism (in my opinion) can indeed happen with VOCs emitted from oilseed rape but I don’t think this would include tree pollen (but you are right, there is a connection with tree pollen, but it is called a different name, I will come to this in a minute).

VOCs (volatile organic compounds) react together in several different ways. Firstly, they most definitely act together to create the total VOC concentration (TVOC), but in addition they can and do act synergistically, where the potency (allergenicity or irritancy) of the resulting mixture is far greater than the sum total of the VOC concentration.

But there is also a third (and fourth) component of VOC emissions and inter-actions that can escalate the potency of VOCs even higher. The cocktail of 22 VOCs emitted from oilseed rape create a biochemical reaction that results in the formation of ozone above the crop. As you will be aware, ozone is well documented for causing/exacerbating asthma.

The connection with tree pollen is a very valid one and I will create a thread on this later. I would say the VOCs from oilseed rape can also act as an “adjuvant” – something that that influences the course of an immune response. Allergists tend to simplify this by saying that the effect causes lowering of immunity, rather than increasing the immunological response (the same thing, but just expressed in a different way).

Take hair,



Thanks Deek,

very interesting. Esp the O3 theory too!

Yes, I have heard about the Varroa (sp?) mite or Virus (??) that is attacking our native honey bees. Also Our lovely fluffy Bumble Bees (Bombus spp) are also declining from habitat loss.

Take care & buzzy wigs!



Och Deek i don't want any wee beasties in your rather fetching yellow wig, and here was me just worrying about latex in the lining. Am sending a beastie deterrant and mask post haste,we can't have our resident specialist incapacitated by adverse reactions to beasties.

I don't like the smell of rape seed, when we drive past them in the country i get wheezy, sneezy and my eyes itch and stream. My Mum who is not asthmatic also gets sneezy, coughs a lot and her eyes get itchy and watery too.

Deek your knowledge on mould and allergies is very much apppreciated, take good care, Lois


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