spray cleaning products

Cleaning Products May Raise Risk of Wheezing and Asthma in Young Children

MedicalResearch.com Interview with:
Jaclyn Parks, B.Sc. Health Sciences
M.Sc. Health Sciences Candidate | Faculty of Health Sciences
Simon Fraser University
Burnaby, B.C

MedicalResearch.com: What is the background for this study?

Response: Childhood asthma is a major public health concern, and many researchers are interested in determining environmental and modifiable exposures in early life so that we can recommend preventative measures. The findings of our study add to the understanding of which exposures in early life may be important to the development of childhood asthma and allergies and allows us to identify specific areas of intervention for parents and other stakeholders involved in protecting children’s health.

MedicalResearch.com: What are the main findings? 

Response: The main findings of this study were that children who grew up in a home with a higher frequency of cleaning product use in early life* had a higher likelihood of recurrent wheeze (35%), asthma (37%), and a combination of recurrent wheeze with atopy (49%) (aka. allergic sensitization) at 3 years of age. We also saw that this relationship may be stronger in girls than boys, but this requires further investigation. When comparing those who used a particular product more vs. less frequently, we saw some increased risk associated with more frequent use of sprayed products, deodorizers, disinfectants (incl. hand sanitizer), and oven cleaners

*Early life was determined as 3 months of age for this study. Results are based on an interquartile range increase (from 25th to 75th percentile) in the Frequency of Cleaning Product Use score (FUS).

MedicalResearch.com: What should readers take away from your report?

spray cleaning products


Response: All parents are striving to maintain a healthy home for their children. We want parents to question the socially accepted norm that a home needs to smell like chemical-based cleaning products in order to be ‘clean’. Instead, we propose that the smell of a healthy home is no smell at all. In the pursuit of obtaining a clean and healthy home (ie. low-allergen, mould-free, and with good air quality), it is important that parents read labels and be informed about the risks associated with the use of cleaning products.



General rules of thumb to reduce your exposure to household cleaning products are;

  • Avoid or find alternatives to sprayed and aerosolized cleaners, disinfectants, and corrosive cleaners,
  • Use products with a shorter ingredient list,
  • Avoid using multiple products at the same time and/or rinse the surface cleaned with water after product use to avoid persistent exposure and the potential for generating secondary pollutants*, and
  • Ventilate and/or avoid the home following the use of these products**.

*Secondary pollutants are created when an interaction occurs between 2 or more used primary pollutants. In addition to pollutants associated with the use of each individual product, the combined use of products allows to the generation of additional pollutants that would not have been created if products were used in isolation of another or others.

**Concentrations of indoor pollutants characteristic of cleaning products stay at elevated levels during and for hours after a cleaning event, so you may want to schedule your day so that you leave the home for a few hours after cleaning with products.

MedicalResearch.com: What recommendations do you have for future research as a result of this work?

Response: Based on the findings from this study, we have identified a number of areas for future research. Some questions may include;

  • More studies like ours to validate and add consensus in a North-American context.
  • Studying how the onset of childhood asthma affects household cleaning behaviours
  • A specific analysis of the disclosed ingredients in these common cleaning products
  • Evaluating whether homemade cleaning products are significantly better for your health and to what extent. The phenomena of ‘green-washing’ in the cleaning product industry is problematic and needs further investigation. 

MedicalResearch.com: Is there anything else you would like to add?

Response: Canada (and other Nations) need to develop a program similar to the REACH program currently in place in Europe. The REACH program requires that all consumer products be diligently tested for adverse health effects before entering the market. Not only do we lack that level of regulation here, we also don’t have enough regulations around the labelling of what exactly is in the products we can purchase.

MedicalResearch.com: What are the main limitations of this study and why? 

Response: The CHILD Cohort Study has a lot of information that allows researchers to ask and answer these sorts of questions, but there are always limits to how much you can ask of these families to devote to the study. The CHILD Cohort Study follows nearly 3,500 children from gestation through to 8 years of age (and beyond, dependent on funding), collecting data through questionnaire, bio-samples and clinical assessments. This present study doesn’t look at how cleaning behaviours may have changed over time with the onset of health symptoms. If you found out your child has asthma or allergies, would you clean more or less frequently? We did consider cleaning product use during pregnancy and found the Frequency of Use Score assigned to the household then, was significantly correlated with the score assigned when the child was 3 months old, suggesting that cleaning product use may not change much over this time frame.

We also don’t yet know if there are particular ‘windows’ of development when a child is most susceptible to these types of exposures (e.g. Is it worse to be exposed in-utero, at 3 months, or at 1 year?). Other research suggests early life exposures, beginning in gestation and extending through the first 1-2 years of life are most important.

One other limitation is that we used questionnaire responses on specific product types to develop this score of overall cleaning product use frequency. While this approach is vulnerable to reporting bias, we chose to ask about use of specific products rather than asking ‘how often do you clean your home’ to minimize bias and be more specific to the exposure agents of interest for this study. We did verify that the products were present in the home, but we did not record the exact brands and ingredient lists of each product used in each CHILD participants home, and not every “spray air freshener” is exactly the same. It should be possible to examine this detail using barcodes on products, though manufactures still often hide ingredients by listing “fragrance” and they are not required to report ingredients that are less than 2% of product.

We assumed that each child was exposed to the products being used for cleaning, although we do not have data on the child’s location during the cleaning, whether the cleaned areas

were rinsed or ventilated afterwards, and other factors that would influence persistent exposure. Cleaners persist in the air causing exposure both to direct users and those who are secondarily exposed over time. For example, a single use of a kitchen degreaser can affect indoor aerosolized concentrations of irritant chemicals for several days (Schwarz et al., 2017)

No conflicts of interest or financial disclosures to report.


Association of use of cleaning products with respiratory health in a Canadian birth cohort

Jaclyn Parks, Lawrence McCandless, Christoffer Dharma, Jeffrey Brook, Stuart E. Turvey, Piush Mandhane, Allan B. Becker, Anita L. Kozyrskyj, Meghan B. Azad, Theo J. Moraes, Diana L. Lefebvre, Malcolm R. Sears, Padmaja Subbarao, James Scott and Tim K. Takaro

CMAJ February 18, 2020 192 (7) E154-E161; DOI: https://doi.org/10.1503/cmaj.190819



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Last Updated on February 20, 2020 by Marie Benz MD FAAD