Allergen Avoidance in the Home – Part 1: Where do the Allergens Come From?
The development of an allergy and asthma management plan is an important step in controlling exposure to allergens. A significant part of this type of a plan is controlling exposure in the home, where people can spend anywhere from 50-90% of their time. But what kind of steps can be taken, and what kind of products should be used, or avoided?
Products that should be considered are made up broadly of:
- products that may contribute allergens
- products that may remove allergens.
Over the next two articles I will give some key information that will allow you to determine which products should matter to you, and how you should determine this.
We’ll start with products that can introduce or retain allergens or irritant particles into your living environment. These include:
- Floor coverings
- Cosmetics/Personal care products
Bedding is one of the most important parts of an allergen control plan. Pillows, duvets and mattresses can all harbour dust mites, which can be the most common trigger of year round allergies and asthma. A dust mite is only about one-quarter of a millimetre and so are too small to be seen with the eye. Dust mites love the warm humid environment of bedding and they feed mainly on flakes of your skin! Both the body parts and waste of the dust mite can act as allergens and so controlling this exposure is crucial.
Pillows, duvets and mattresses can all be encased in dust mite proof encasings to ensure that, even though there are dust mites in these products, they cannot escape. These encasements have to be made from a fabric that is impermeable to dust mites and their particles. In order to achieve this, the pore size of the fabric has to be less than 10µm (one tenth of a millimetre). While this is achievable, combining this small pore size with adequate breathability can be a bit more challenging. The importance of breathability is that if no air can pass through the fabric it becomes very uncomfortable to sleep on, and so compliance can then become a problem, in addition to being a poor quality product.
An additional measure to control dust mite exposure from bedding is to wash the article in water hot enough to kill the dust mites (130°F/54.4°C) and remove the allergens. However, for mattresses, this is obviously just not possible, and the quality of some pillows and duvets may not facilitate this type of regular cleaning.
Some bedding products may use chemical finishes to impart anti-mite activity, or even a more wrinkle free finish (!) and some of these chemicals used may be irritant on inhalation.
So, important things to look for when buying bedding as part of your allergen control plan include:
- What is the pore size of the fabric?
- Has its barrier efficacy been physically tested?
- Has it undergone multiple wash testing?
- What chemicals have been used in its construction and finishing?
- Have these been tested?
Paints and adhesives do not trigger allergenic reactions per se. The compounds that they may contain, volatile organic compounds, may however cause breathing problems for sensitive individuals. VOCs can be emitted at the application of product, and can thereafter be emitted for some time. Consumers should review the paint or adhesive product for what (if any) testing it has undergone to indicate low, or no, VOC levels. While this is very important, in a similar way to bedding products, efficacy is fine, but there must also be quality of product. For paints this is measured by a scrub resistance test to ensure that a paint will withstand use. Make sure that any low or no VOC paint that you purchase has achieved the requirements of the national or international performance standards.
- What VOCs are emitted by the paint/adhesive?
- What levels are these emitted at and how long for?
- What is the scrub resistance of the paint?
- Have these been tested?
Floor coverings may include carpet, linoleum or laminate wood flooring. Floors are natural residence areas for all kinds of dirt, dust and allergens, different types of flooring will interact with these contaminants in different ways. Linoleum or laminate wood flooring have been recommended for a long time for those suffering from asthma and allergies, due mainly to their low ability to retain allergens, and their ease of cleaning. Similarly to paints/adhesives, care must be taken in terms of any solvents or adhesives that are used in the laying of this flooring. The recommended method of cleaning must also not expose the consumer to increases in airborne allergen load, and ideally this type of laminate flooring should not retain allergen, that may then result in its release into the environment. While this may be beneficial for some sufferers, it is not the whole story. While carpet can retain allergen, it can also act as a sink for allergens. Where laminate floors may allow dust and allergen to float around, the carpet traps the allergen within the pile of the carpet. Indeed, several International research groups have conduction studies of a range of carpet types, cleaning methods and disturbance techniques and concluded that effectively cleaned carpets can trap more allergens and other particles, resulting in fewer particles escaping into the air. You need to consider what are important triggers for your allergies ad make an informed decision of what type of product suits your lifestyle best.
- What is the recommended cleaning to ensure least exposure to allergens?
- Is adhesive used in the laying of the flooring? (See section above)
- How much work do you want to put into cleaning?
- Are there professional cleaning services available?
- What is the type of traffic like that the flooring will experience?
- What is the pile depth of the carpet?
- To what extent does it retain allergen (without releasing it)?
- Have these been tested?
Plush toys, similarly to bedding, can act as a significant reservoir of dust mites, as well as being a potential source of VOCs. The stuffing of plush toys can make them an ideal breeding ground for dust mites, and therefore a key part of any allergen control plan for children. It is inevitable that plush toys will contain dust mites, and so the key part of a control plan is to minimise build-up of the dust mites; the most effective way to do this is through regular washing. It can be difficult to know how regularly to wash a stuffed toy to prevent increased exposure to dust mites, but a general guideline of once every 6-8 weeks is a good place to start. The temperature of the water should be at least 130°F/54.4°C and the item should be dried thoroughly. While this approach is very good from a practical perspective, washing can take its toll on stuffed toys, particularly ones that have not been constructed from quality material. Before purchasing a product that your child will become emotionally attached to, it is a good idea to check if it has any testing performed to show that it will withstand multiple washings. You do not want to be in a situation where your child’s new favourite toy falls apart after the second wash!
- Does the toy emit VOCs?
- How quickly will the toy accumulate dust mites?
- What are the recommended wash instructions?
- Will it withstand multiple washings?
- Have these been tested?
Cosmetics/Personal Care Products
Any allergenic response is due to a natural compound, peanuts, dust mites, pollen, etc. There are two types of responses that a sensitive individual may have to cosmetics or personal care products. The first is an allergenic response to natural compounds present in the product, this could be an oil or a scent for example. The second type of response is a sensitised response to a synthesised chemical, for example an artificial scent. Knowledge about your own allergies and sensitivities will provide a good start in terms of selection of cosmetics or personal care products. If you are not sensitive to essential oils, then products containing these compounds should be fine, if you are allergic to nuts for example, there are a variety of cosmetic products that can contain nut oils and so maybe should be avoided. Some cosmetic products do self-certify themselves as being ‘hypoallergenic’; this has been discussed in a previous article, however in essence there is no definition of what (if any) testing is required for a product to describe itself as hypoallergenic and as such from a practical perspective, is meaningless. Cosmetics and personal care products can contain a wide range of compounds and so it can be quite difficult to determine which are appropriate for you. The best defence here is as much knowledge about your own sensitivities as possible, that will allow you to make an informed decision.
- What are you allergic/sensitive to?
- Does the product contain these compounds?
- Has the product undergone any testing to indicate that it is more suitable for allergic/sensitive individuals?
About the Author
Thanks to Dr. Tim Yeomans for this insightful article.
Dr. Tim Yeomans is the Centre Manager for Shannon Applied Biotechnology Centre, a collaboration between two third level colleges in Ireland. Tim holds a PhD in Microbiology and postgraduate qualifications in Technology Commercialisation and Innovation Management. Tim has worked in research and development for 20 years, both in industry and academia. In his role in Shannon ABC, Tim is responsible for the scientific direction of the Centre, intellectual property management and business and technology development.”
allergens, bedding, paint, adhesives, floor coverings, toys, care products, cosmetics, asthma, allergy, asthma & allergy friendly, indoor air quality
Related Internal Links
Manchester Asthma and Allergy Study: Low-allergen environment can be achieved and maintained during pregnancy and in early life Adnan Custovic MD, Bridget M. Simpson RN, Angela Simpson MD, Claire Hallam BSc, Mark Craven MSc, Martin Brutsche MD, Ashley Woodcock MD Journal of Allergy and Clinical Immunology Volume 105, Issue 2, Part 1, February 2000, Pages 252-258
Environmental allergen avoidance: An overviewPeyton A. Eggleston, MDa, Robert K. Bush, MDb Baltimore, Md, and Madison, WisFrom the Department of Pediatrics, Johns Hopkins Hospital, Baltimore; and the Department of Medicine, William S. Middleton VA Hospital, University of Wisconsin–Madison