Things to consider when building/designing a bedroom for those impacted by asthma and allergies

Things to consider when building/designing a bedroom for those impacted by asthma and allergies

We know that people spend up to 90% of their life indoors and 30% of this time may be in the bedroom. Infants and young children spend even longer than this. Integral to the designing of a well-functioning bedroom are the concepts of comfort, wellness and health but the bedroom can be rife with asthma and allergy triggers with the potential to impact on these concepts and turn a bedroom into a negative space.

Why does controlling triggers matter ?

60 million people in the United States are impacted by asthma and allergies and each of these individual’s lives could be made easier by relief of their symptoms. Asthma accounts for 9.8 million doctor’s office visits and 1.8 million emergency department visits each year in the United States. It is the third-ranking cause of hospitalization among children younger than 15. More than 11.4 million people with asthma, including more than 3 million children, report having had one or more asthma episodes or attacks in 2017 and it is the top reason for missed school days; in 2013, about 13.8 million missed school days were reported due to asthma.

Each day, ten Americans die from asthma, and in 2017, 3,564 people died from asthma. Many of these deaths are avoidable with proper treatment and care. A cornerstone of this care is avoidance of triggers factors.

From 2008-2013, the annual economic cost of asthma was more than $81.9 billion – including medical costs and loss of work and school days ; $3 billion in losses due to missed work and school days, $29 billion due to asthma-related mortality, and $50.3 billion in medical costs.

Allergies are the 6th leading cause of chronic illness in the U.S and more than 50 million Americans have experienced various types of allergies each year. Allergic rhinitis, often called hay fever, affects 6.1 million of the child population and 20 million of the adult population. The annual cost of allergies exceeds $18 billion.

Allergies can have a severe impact on quality of sleep and therefore quality of life. Itchy nose, eyes and throat, runny nose, headache and sneezing can lead to chronic sleep loss. Studies have shown that people with allergies have an increased risk of insomnia, hypersomnia, sleepiness and memory loss. The swelling of the nasal passages that occurs during an allergic reaction narrows the airway passage and can cause the dangerous phenomenon of sleep apnoea. All these lead to daytime fatigue, memory impairment and difficulty concentrating. So for a better night’s sleep for those 50 million Americans who have allergies, the right build and design of the bedroom can be crucial.

It is also worth considering the fact that although indoor air quality is of particular concern for those affected by asthma and allergies, a healthier home is of broader benefit to all.

What factors in the bedroom need to be considered ?

1.     Environmental control

Exposure to asthma allergens or irritants known as triggers is known to increase asthma symptoms. Allergens cause this by  provoking an allergic reaction. Eliminating or reducing the source of triggers and avoiding exposure to triggers is called ‘environmental control’ and it is the cornerstone of modern asthma management.

Allergens include dust mite, pet dander, pollen, rodents, insects and mold. Common irritants are smoke, strong fumes, pollution, ozone, volatile organic compounds (VOCs) and other chemicals. VOCs are chemicals emitted as gases from liquid and solid materials.

Effective trigger avoidance requires a multifaceted, comprehensive approach and therefore designing/ renovating a room provides an ideal opportunity to think and plan from the ground up. Materials used in construction, remodelling and decorating are major contributors of indoor pollutants that can greatly affect the air quality in the home.

The end goal of good environmental control in the bedroom is to ensure consistently good indoor air quality, with minimal irritants and allergens. Therefore when building and designing, it is crucial to consider all materials used at all stages of the build- from insulation to paint to bedding to furniture- but also how these materials will perform in situ, alongside each other and the room’s inhabitants and how they will perform into the future.

2.     Paint

bedroom paintPaint can contain many chemicals that are considered a problem to those impacted by asthma and allergies.  Volatile organic compounds (VOCs) are probably the most cause for concern. These are chemicals emitted as gases from liquid and solid materials, and in particular are associated with oil based paints. VOCs are a known asthma trigger. They can also cause eye, nose, and throat irritation; headaches, loss of coordination and nausea; damage to liver, kidney and central nervous system.

Other harmful chemicals in paint:

There are a range of other chemicals that may be found in paints and may pose health concerns in general. These include:

  • Formaldehyde. Formaldehyde, a VOC, is added to paint to inhibit bacterial and fungal growth. An increase in formaldehyde in indoor air after painting correlates with increased asthma symptoms and exposure to it can cause irritation of the eyes, nose and throat and some neurological effects.
  • Acetaldehyde. Added to paint as a binder, exposure to acetaldehyde can cause irritation of the eyes, skin and respiratory tract. Acetaldehyde is also a specific inducer of airway hyper-responsiveness in asthmatic patients.
  • Mercury. Phenylmercuric acetate is used as a preservative to prolong the shelf life of paint by inhibiting the growth of bacteria and fungus in water-based paints.
  • PGE(propylene glycol and glycol ethers). Used in water based paints in order to reduce the overall VOC levels however, a study in 2010 showed a correlation between PGEs and greater risk of developing allergic diseases.

 Consider the following when choosing paint and applying paint:

  • Minimise sources of VOCs and other chemicals – select a paint that has been manufactured (and preferably tested by a third party) to be low in VOCs.
  • Water-based paints have significantly lower solvent and VOC content and are generally a healthier choice
  • Use of a water based paint also removes the need for strong cleaning chemicals for paintbrushesand therefore removes an additional source of VOCs
  • Because paints can emit chemicals for many days (up to 14) after application, the area should be kept as well ventilated as possible during this time
  • Paint well in advance of use of the room if possible, to allow time for VOCs and chemicals to complete their emission timeline. This will reduce the occupants exposure to the harmful chemicals

In the past decade significant steps have been taken to reduce and remove the amount of harmful chemicals used in paint so that now there is a much wider choice of paint available. Paint products should be selected carefully, taking due consideration of any chemical sensitivities the client may have. Thankfully, now paint tins are well-labelled and informative. A few moments checking the tin for information and evidence of third party testing is well worth it.

3.     Bedding

Bedding is a crucial element to address within the bedroom environment. Young children can spend more than 12 hours a day in a bed and up to 8 hours a day as they grow older. Older people too, or those with illness, may spend many hours in bed and therefore exposed for long periods of time to potential allergens.

The house dust mite is the most common trigger of indoor allergies, leading to long-term poor quality sleep. High levels of dust mites can be found in dust from mattresses and pillows. An allergic response to the presence of dust mites can be to the intact live dust mite, or to their body parts so protection must be effective against active transport (the intact dust mite travelling to different parts of the bed) and passive transport (body parts and, in particular, the excrement produced by the dust mite, throughout the bedding).

Effective bedding encasings are a well-established way to protect sensitive individuals from exposure to dust mite allergen and can be applied to mattresses, comforters and pillows. But house dust mite allergen can be as small as 10 microns and so preventing passage of these minute particles through textile fabrics can be challenging. The bedding items must form a sufficient barrier, yet be comfortable and breathable at the same time.

If there is dust mite allergen on a product, it should be possible to remove this material through washing. Products should be of suitable quality to enable them to be washed regularly at least 40 degrees C to remove dust mite allergen and therefore reduce allergen build-up, yet not lose their integrity. Encasements for pillows, mattresses and comforters will have some kind of fastener, like a zipper, and passage of allergen through these parts of the product must also be tested and proven to prevent allergen passage. The integrity of the fastener/zipper must be maintained after regular washing.

Some chemicals used in bedding can cause sensitivities or even allergic reactions. Bedding products should be selected to ensure that they do not contain trigger chemicals above biologically relevant levels. While most reputable suppliers will have engaged in health and safety testing, the global supply chain means that it is possible that some products could enter the supply chain that may not be as safe as others.

4.     Allergen and Chemical Exposure in the bedroom

Controlling exposure to allergens and chemicals from many different sources is a key aspect of a healthy bedroom environment. High levels of dust mites can be found in dust not only in bedding and flooring but also on surfaces, upholstered furniture, clothes, soft toys and drapes so these aspects of the build and design must be considered. There is little point in advising a client on appropriate bedding if the remainder of the bedroom acts as a reservoir for allergens.

The stuffing of plush toys makes them an ideal breeding ground for dust mites and so a key part of a control plan is to minimise build-up of the dust mites. Pollen too can get trapped in plush toys. Additionally, toxic chemicals including VOCs, fire retardants, phthalates and even lead may be used in the fabric or plastic of the toy, exposing a child to airborne irritants that can aggravate asthma or allergic reactions.

The most effective way to remove allergens is through regular washing or freezing, but between washes plush toys should ideally be stored away to minimise dust and pollen collection. As part of the renovation/build, built-in storage for plush toys may be considered.

Concentration of VOCs indoors can be 10 times that of outdoors due to off-gassing from various contents of the room and from building materials. Cheaply produced furniture tends to off gas more, releasing fumes contributing to poor air quality. An alternative may be to choose antique or used pieces that may be more environmentally friendly and non-irritant . Building materials, insulation and flooring can be sources of potentially harmful chemicals and contribute negatively to the quality of the indoor air. Knowledge of what specifically triggers the clients asthma and allergies can help you make the safer choice during the build.

The approach to providing the client with a room that will positively impact his/her life must be holistic and forward thinking. How the building materials, flooring and contents of the room can be cleaned and maintained may not impact you, the builder/designer, but will be crucial when it comes to long-term good quality indoor air for the inhabitant.

5.     The Term ‘Hypoallergenic’ Has No Scientific Basis

The demand for products that are safer and healthier is rising. Awareness of the importance of good indoor quality and its impact on health has become a real focus in recent times, largely as result of the global pandemic. It seems that finally, we are beginning to really ‘see’ our air. But many brands are capitalizing on this by making health claims that are scientifically unfounded.

The dictionary meaning of hypoallergenic means ‘relatively unlikely to cause an allergic reaction’. The term implies it is healthier, safer, superior even than the product its sitting next to on the shelf. But products displaying the claim or ‘hypoallergenic’ or ‘allergy free’ have not been subjected to any kind of standardised testing.

In reality, there is no Federal standard by the FDA or the Consumer Products Safety Commission (CPSC) that governs the term hypoallergenic. That means, just like ‘pure’ and ‘natural’, the term ‘hypoallergenic’ can be used on virtually any product.

Similarly with the term ‘fragrance-free’.  A study carried out by Northwestern Medicine showed that nearly half of products claiming to be fragrance free actually had a fragrance. It also found that 83% of products with hypoallergenic labels included a potentially allergenic chemical.

One thing is clear, the terms ‘pure’, ‘natural’ and ‘hypoallergenic’ are nothing more than marketing terms and should be treated as such. The terms may imply quality, high end or a safer product but often it turns out that cost does not equal quality or safety.

Third party certification on the other hand is an independent, objective review of a product’s safety and of its performance and therefore does result in safer more reliable products. It has no financial interest in the sale of the product and it distinguishes those manufacturers making compliant products from those who do not. Taking the time to check a product for third party certification is always worth it.

6.     Humidity

bedroom humidifierA comfortable indoor humidity is between 30-50% and this is what the Environmental Protection Agency (EPA) recommends. The human body is sensitive to humidity so anything lower than 30% feels too dry and anything over 50% too humid. At temperatures usually found indoors, this humidity level makes the air feel approximately what the temperature actually indicates. Controlling the indoor humidity within these parameters contributes to better indoor air quality.

If the humidity in the bedroom is too low, it can feel colder than it actually is. The dry air dries out skin and mucous membranes and can cause itchy skin, chapped lips and a parched, sore throat first thing in the morning. Very dry air can make eczema worse.

Low humidity can precipitate a cough even in those people with a completely healthy respiratory system by drying out the airways and is a known asthma trigger.

Very dry air increases the chance of catching airborne viruses like a cold or the flu – possibly because they can survive longer in dry, cool conditions but also because low humidity lowers the immune system. Studies exposing mice to influenza virus have shown that at low humidity, nasal cilia (the microscopic hairs in the nose) become less effective at removing viral particles and mucous. Airway cells are less able to repair damage caused by viruses and, finally, interferons – signalling proteins that tell neighbouring cells that there is trouble ahead – are impacted. This fact is hugely relevant during the COVID19 pandemic. How is the SARS-CoV-2 virus affected by humidity? It appears that, like Influenza virus, low humidity is associated with increased infection. There may be many reasons behind this and the virus is still under major scrutiny as research is ongoing. We do know that when humidity is lower, the air is drier and the infected aerosols are smaller. Smaller aerosols can stay suspended in the air for longer and this increases exposure to the disease. When the humidity is higher, the larger aerosols will fall more rapidly onto surfaces, thus removing them from the air where they are more likely to be inhaled. Researchers working on a study in Sydney discovered a 1% decrease in humidity could increase the number of COVID-19 cases by 6%.

Low humidity also affects the contents of the bedroom- it dries out furniture and plants, paint on the walls can crack and flake, wood floors and furniture can split and crack. It increases static electricity, causing sparks when touching off something or someone.

If a humidifier is to be considered as part of the renovation project, it should be chosen carefully with regard for its ability to achieve and maintain appropriate humidity levels and its capability to sanitise the water during use. 

Conversely, if the humidity in the bedroom is too high it can feel hotter than what the temperature actually reads. Rooms feel unpleasantly stuffy, often leading to overuse of the air conditioning in order to lower the temperature, thereby increasing energy costs.

High humidity can also be a problem for people with asthma. When the air is wet, it can feel harder to breathe and this can make body temperature rise, causing sweating. Subsequently, this leads to dehydration. All of this combined can trigger asthma symptoms.

High humidity levels provide an environment for two common asthma and allergy triggers: dust mites and mold. Dust mites are one of the most common allergen triggers for asthma and they thrive in humidity levels at and above 70%.

Moist, damp air – anything above 50% but typically 60-70% humidity – is the ideal environment for mold to flourish. Mold is a fungus that can be detrimental to health and the toxins, called mycotoxins, cause eye and throat irritation, skin rashes, sneezing, itchy throat and coughing, and can contribute to asthma attacks. For mold to affect breathing, it doesn’t even have to be visible. Water and water vapor in clothing, sofas and curtains can make them turn moldy and malodourous.

If high humidity is a concern then increasing ventilation will help the air dry out. Thus  air conditioning or a dehumidifier, depending on the climate, may be a necessity in the renovation. A dehumidifier removes water from the air until relative humidity is reduced to the required optimal level. Once it has reached this level an effective dehumidifier should automatically maintain that comfortable level. For the safety of the occupant of the bedroom, exposure to allergen and fungal spores during a filter change and water receptacle emptying procedures must remain below certain levels. Ideally the dehumidifier must provide a care code to indicate filter change and water receptacle emptying recommendations.


In order to achieve the goals of comfort, wellness and health when undertaking a bedroom build/renovation a holistic, human-centred approach must be taken. Understanding an individual client’s needs, particularly when it concerns asthma and allergies is vital to the success of the project. Through consideration of factors such as environmental control, paint, bedding, humidity and allergen and chemical exposure, the control of asthma and allergy triggers becomes inherently part of the build and enables the inhabitant to live with improved indoor air quality. The bedroom project is a truly great opportunity to improve an individual’s quality of life.

Do you or your company wish to become a Certified Asthma and Allergy Aware Trusted Advisor?

Developed by asthma and allergy science experts at Allergy Standards, the same company behind the world famous asthma & allergy friendly® Certification, the fully online course will teach you how to build a better air quality environment for customers. Our courses are designed to create educated teams capable of advising customers, to help sell more products and build greater trust.

For more information Click Here

Medical & Lifestyle Author Dr Anna O'Donovan

Medical & Lifestyle Author Dr Anna O’Donovan

About Dr. Anna O’Donovan – Medical & Lifestyle Author 

Anna is a mum of three children, one with allergies, and she suffers from allergies and asthma herself. She is a qualified doctor and worked as a General Practitioner and as a dentist for a number of years. She is also an award-winning author.


Key Words

indoor air quality, bedroom, environment,architect, construction industry, design, air quality, indoor air quality, asthma, healthy, allergies, allergens, air purifiers, healthy home, air cleaner, building materials, bedding, humidity, humidifier, paint, VOCs, chemicals, 

References and further reading

Pedriatrics:Indoor Environmental Control Practices and Asthma Management Click here 

Northwestern: Mislabeled moisturizers create problems for skin disorder sufferers Click here

AAFA: Asthma Facts and Figures Click here

AAFA: Allergy Facts and Figures Click here

What Chemicals are in Paint Click here

Medical News Today: How humidity may affect COVID-19 outcome Click here

Humidifiers: Air Moisture Eases Skin, Breathing Symptoms Click here


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