Allergen avoidance in the home – Part 2: How to get rid of allergens?
This is the second of a two-part article on the development of an allergy and asthma management plan for the home. This article will deal with products that can help with the control of exposure to allergens through their removal or treatment.
These can include:
- Vacuum cleaners
- Carpet washers
- Washing machines
- Air filters
- Cleaning products
- Air conditioners
A vacuum cleaner is a key part of allergen control, whether you have laminate or carpeted flooring. Using a brush on laminate flooring can aerosolise dust and particulate matter and should be avoided. Not all vacuum cleaners are created equal however, and there a number of characteristics that should be assessed when purchasing or using a vacuum cleaner.
- Allergen removal efficacy – removal from laminate flooring should be easy enough, but can the vacuum cleaner remove allergen sufficiently from a carpet? Has it been tested to do this? Some carpets can be appropriate for use in a house where there are sensitivities to allergens, however they must be cleaned appropriately; in order to do this, the vacuum cleaner must be capable of this level of allergen removal.
- Filter integrity – as the vacuum cleaner sucks in air, it must also exhaust air. It is very important that the integrity of the filter means that allergen is not simply exhausted out the back of the vacuum cleaner.
- Bag change or receptacle emptying – an important aspect of use of a vacuum cleaner for allergen exposure control is that the user is not then exposed to high levels of allergen at bag change or receptacle emptying stage. While bags do provide more containment for allergen exposure, dependent upon the type of bagless vacuum cleaner, these can also be appropriate, dependent upon the particle dynamics that occur on emptying. If you are unsure, this task should be completed outdoors in order to ensure maximum dilution of any released allergens.
- Has your vacuum cleaner been tested to determine its allergen removal efficacy on carpeted flooring?
- Vacuum cleaners can have varying abilities to remove particles and allergens from carpeting, based on suction capability, as well as cleaning head used. Most vacuum cleaners are tested against ‘synthetic dust’ which has a very well defined particle size, but is however very different to normal house dust. Ideally you should select a vacuum cleaner that has been tested for its ability to remove real allergens from a carpet.
- Have the filters and filter system been tested to ensure no release of allergens?
- Filters and filter systems must retain their integrity to ensure no release of allergen once vacuumed.
- What are your exposure risks at bag change and receptacle emptying, and has this been tested?
- Particle measurements by reputable companies can determine both the particle size and amount that a user may be exposed to, as well as allergen load – ask your vacuum cleaner provider if this has been done for their model.
While laminate type flooring is often recommended for those suffering from asthma and allergies, carpeting can also be an appropriate option. This may be based on its ability to retain, and not easily release allergens, and to be cleaned appropriately in order to remove retained allergen. One way to remove allergen from carpeting is to wash the carpet. As with vacuum cleaners, not all carpet washers are created equally. The carpet washer should be capable of deep removal of allergen from the carpet through the action of washing, and should utilise an appropriate detergent. In addition, the amount of water used for washing the carpet should not be excessive; if the carpet does not dry appropriately it can make an ideal breeding ground for mold. Finally, the emptying of the receptacle should not expose the user to excessive allergen, although this is much less likely to occur in carpet washer than a vacuum cleaner due to the allergens being retained in the water.
- Has your carpet washer been tested for its ability to remove allergens from carpet?
- While allergen retention is a capability of many carpets, this has to be effectively removed at some point to avoid over-loading and re-release of allergen. A carpet washer should be capable of effectively removing this allergen load.
- Does the carpet dry in a reasonable period of time following cleaning?
- Excessive use of water by a carpet washer will leave the carpet wet, and dependent upon the heating system in the home, may allow mould to grow.
A washing machine is a key part of an allergen reduction plan – there are a number of items in the home that can accumulate allergen that can be rendered ‘safe’ following washing. These include:
- Pillow cases
- Duvet covers
- Mattress encasements
Dust mites are sensitive to elevated temperatures, and the ingredients of some washing detergents can degrade proteins (including the dust mite proteins that can induce an allergic response). The key measure for a washing machine therefore is that it can reach the temperature indicated on the wash cycle – for killing dust mites, this needs to be at least 130°F (54.4°C). While all washing machines will include a hot wash cycle, this temperature must be achieved in a consistent way within the drum, rather than peaking at a particular hot spot.
- Does your washing machine consistently reach a minimum of 130°F (54.4°C) and has this been tested?
- This is the critical kill point for the house dust mite, some washing machines may reach this temperature but only at certain spots in the drum (‘hot-spots’). Ensure that your washing machine has been tested appropriately that a consistent high temperature is reached in order to kill house dust mites.
Many homes and work environments have HVAC systems (heating, ventilation and air conditioning), for central control of their air systems. HVACs draw air in from outside and circulate through the home and as such have a filter in place to ensure that particulate matter from outside is not drawn inside. For those suffering from asthma and allergies, this plays a central role in controlling exposure to outdoor allergens such as pollen. Filters are generally ranked according to the particle size that they will trap, in line with this, the smaller the particle size, the more power that is required to draw air through the filter. Over time filters will need to be replaced as they become clogged and, in a similar way to vacuum cleaners, the exposure of a sensitive individual needs to be considered when establishing a removal and replacement protocol. The efficacy of a filter is dependent upon the integrity of the seals into which it is placed and when such a system is put in place, you should ensure that replacement of filters does not result in compromising the filter system.
- What particle size does my filter remove?
- In general filters which can filter out a minimum of 10µm (this is 1/100th of a millimetre or less than 1/1000th of an inch) are appropriate for allergen removal.
- How long should it last under normal use?
- This will depend on the area that you live in and how often the system is used, however for cheaper fiberglass filters (which may be less effective at filtering) every month may be necessary, and for more expensive, effective filters, once every 6 months may be sufficient.
- How is it replaced?
- In general, filters slot out from a receptacle in the wall or unit, you should be careful of having your breathing zone too close to the filter when removing, in case of allergen release.
- What are my exposure risks during replacement?
- The function of a filter is to retain small particles (including allergens), as such they will be a significant source of allergen, which may become released during filter change. It is possible for filter companies to determine particle size and amount, as well as allergen load of released particles during changeover – you should ask your filter supplier if this has been done, and if so, what the recommendations were.
Cleaning products are a vital part of keeping a clean house and removal of allergens. In general, cleaning products will not pose an allergenic risk. Some cleaning products do contain natural compounds, and this is where any allergenic response may come from. The vast majority of cleaning products contain predominantly synthetic compounds and so any reaction risk may come from skin contact or inhalation of irritant chemicals which may cause breathing problems in sensitive individuals. Prior to use of any cleaning product, you should review the ingredients for compounds that you know that you are either allergic or sensitive to.
- Do you have allergies to natural compounds in the cleaner?
- Some cleaners may contain natural compounds such as tea tree oil, plant extracts and essential oils; in general any allergic reaction is more likely to be due to a skin exposure, rather than inhalation.
- Are you sensitive to any of the chemicals that it contains?
- If you have allergies, you should find out specifically what you are allergic to, in order for you to be able to better control your exposure.
- Does it remove allergens effectively; has this been tested?
- There are a wide range of cleaning products, for a wide range of applications. For someone who suffers from allergies, a vital function of a cleaning product is to remove or degrade allergens. It may be assumed that cleaning products will do this as a matter of fact, however it must be established that the products remove, rather than redistribute the allergen, and that they don’t introduced allergen into the breathing zone.
- Does it introduce chemicals or VOCs into the breathing environment of the user?
- Many cleaning products are delivered through a spray system, of either aerosolised or droplet particles. These products may contain irritant chemicals that, on inhalation, may cause breathing difficulties. In particular, for those with inhalation sensitivities, testing should be performed to ensure that the droplets, or aerosolised particles, drop out of the breathing zone in a rapid period of time.
Air conditioners provide a dual function of controlling temperature and relative humidity in home environments, as well as potential removal of allergens through a filter system. House dust mites proliferate at relative humidities above 50%; maintaining home relative humidity at less than 50% can therefore assist in the control of this pest. The ideal relative humidity for comfort and health is between 40-50%, an air conditioner is an ideal way to keep this control. Most air conditioning systems will have a filter system in place as it circulates the air, while it is not the primary function of air conditioners to remove allergens, change of filter should be considered as allergen may have built up on the filter during use.
- Does the air conditioner control relative humidity appropriately between 40-50%?
- The optimum relative humidity levels for comfort and health are 40-50%, relative humidity levels above 50% can support the proliferation of house dust mites. As such air conditioning units need to be capable of strictly controlling the relative humidity within the 40-50% range.
- Does the air conditioner filter the air?
- If the air conditioner does filter the air, the particle size it retains should be determined (see HVACs above). In addition, you should also review how the filter is changed to minimise allergen exposure.
There are two sides of the same coin for managing your allergies – control your exposure to sources of allergens and take appropriate measures to remove allergens from your immediate environment. The key part of this is to have the appropriate information to make positive decisions about your exposure potential. There are a range of products that can contribute to allergen exposure, however these do not have to control your life and steps can be taken to minimise exposure. Where the introduction allergen into your immediate environment cannot be prevented, there are a range of removal and treatment measures that can be taken, and have been summarised above. Information is critical, as well as the informed analysis of this, I hope that the information contained in this series provides some help on this!
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.
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