July 2020, Dublin, Ireland We are announcing the development of a new certification standard for bedding containing Merino Wool.
Allergy Standard Limited (ASL) is excited to announce a new addition to its Standard portfolio: ASP:02-25/101 Addendum for bedding products which contain Merino Wool.
This short article summarizes what is relevant to people with asthma and allergy when looking at wool and how we made sure that we offer a safer choice to those with asthma and allergy. It discusses wool fibers, lanolin and chemical residues and how we develop a Standard.
A more complete and in-depth research article is available to Portal members-only.
- If you are already a member, the full article is accessible here
Skin sensitivity to wool fibers:
Wool has been traditionally believed to be an irritant due to the sensation of some wool fibers on the skin – or ‘prickle’ – from heavier fibers. In other words, the thick fiber ends press into the human skin hard enough to activate nerve endings.1 However, this has been questioned recently in scientific literature.
New manufacturing techniques, the use of finer wool fibers, research studies and clinical trials to verify research results have challenged the notion that wool is in itself an irritant. Although one caveat of these studies is that they are often supported by trade associations. they disclosed these possible conflicts of interest, followed a scientific methodology with ethical approval from academic institutions and underwent peer review before publication. 2–4
One emerging wool product in this category is Merino wool. It is named after the Merino breed of sheep it comes from and it is believed that the breed may have originated in Spain in the late Middle Ages, making its way to Australia in the 19th Century where it has played an important role in the country’s economic development while becoming endangered in Europe. Merino Wool is known for its softness, breathability and fineness.5–7
Lanolin, or ‘residual grease’, a natural wool grease produced by sheep, is widely used in cosmetics, skin care products and mechanical lubricants. It has also raised concerns with its links to skin sensitivity. There is some debate in the literature regarding the sensitizing properties of pure lanolin, or most likely one of its components, wool alcohol. 8,9 The concentration of wool alcohol used in patch testing – where a skin reaction is reproduced by applying allergens by direct contact on intact skin of patients suspected of being allergic – is much higher than what even high exposure via wool bedding would be. Here as well, manufacturing methods have improved in such a way that lanolin content in Merino wool bedding is unlikely to cause any reaction2.
Chemical residues from processing
A less studied side of possible allergies to wool is the skin reaction to traces of chemical residues that may have become incorporated into the garment following processing of the fabric. It is possible that some people diagnosed with lanolin allergy are in fact reacting to such chemicals (formaldehyde, chromium). 2
It is already part of the asthma & allergy friendly® standards developed for bedding certification to evaluate items for presence of allergenic and irritant chemicals (including formaldehyde and chromium) and therefore any submitted bedding product would be tested for these chemicals.
From the research reviewed and the consultation of subject matter experts in the field of asthma and allergies, ASL drafted a new asthma & allergy friendly® Certification Addendum for thbedding containing Merino wool (ASP:02-25/101). The Addendum was approved by the ASL Scientific Committee, reviewed by an independent panel of medical experts in the field of asthma and allergies and is now available for bedding manufacturers to test their products against and become certified.
Why just Merino wool?
The current addendum relates to Merino Wool and does not include other types of wool as research to date has focused on Merino Wool. It is not appropriate to apply this standard to other types of wool, because of the different nature of allergenic response possible where different animals and secretions are concerned. For example, angora wool is listed as an asthmagen by the Association of Environmental and Occupations10. At such time as research becomes available or if manufacturers are seeking to certify other types of wool, consideration will be given to their inclusion in this standard.
To be part of the asthma & allergy friendly® Certification Program, a bedding product which contains Merino wool must pass all the criteria from the Certification Standard relating to that product category, in addition to the criteria listed below. For example, a pillow with Merino wool must first meet all criteria laid out in ASP:02-01/102 Pillow Standard as well as the two criteria below.
- Mean fiber diameter of the Merino Wool must be <19.75µm with greater than 95% of fibers under 30µm.
- Residual grease in the Merino Wool must be <1%.
We have just seen that wool fiber diameter, lanolin or ‘residual grease’ and chemicals introduced during the manufacturing process are of relevance to those with asthma and allergy. The latter is already covered by other asthma & allergy friendly® Certification Standards and ASL has established criteria for the former two. Different wools can also have different effects on people with asthma and allergy and it is very important to investigate them before accepting them as part of the asthma & allergy friendly® Certification Program.
A more complete and in-depth research article is available to Portal members-only here.
Merino wool, lanolin, asthma, allergy, asthma & allergy friendly®, chemicals, certification program, allergy insights, standards