Adult and children's use of hand sanitizer during a pandemic — an observational study

The COVID-19 pandemic led to increased public health recommendations for hand hygiene, emphasizing hand sanitizer use, especially in schools and childcare settings. Hand sanitizers, while effective in reducing transmission, contain various substances and impurities with potential health effects like skin irritation, eye damage, dizziness, and even cancer. While regulatory bodies like Health Canada and the European Commission have assessed the safety of these chemicals, the pandemic dramatically altered hand sanitizer usage patterns, necessitating updated data on frequency and amount of use to accurately assess exposure risks. Pre-pandemic research is insufficient because it doesn't reflect the increased usage during the pandemic and lacks data on school/childcare settings. Statistics Canada reported a massive increase (792%) in hand sanitizer sales in March 2020, indicating a significant shift in consumer behavior. Reports of increased eye injuries in children due to hand sanitizer contact further highlighted the need for research specifically focusing on children's usage patterns, particularly in school environments where children may be more vulnerable due to their lower body weight and hand-to-mouth behaviors. This study aimed to gather Canadian-specific data on non-occupational hand sanitizer use among adults and children, focusing on the increased usage during the pandemic to improve the accuracy of human health risk assessments.

Existing literature on hand sanitizer use, while offering some information on usage patterns and potential exposure, lacked data specifically pertaining to the pandemic context and, crucially, children's usage in school/childcare settings. Studies like Wu et al. (2010) provided pre-pandemic data on hand sanitizer use in California households, but these figures are not applicable to the dramatically altered usage patterns observed during the pandemic. Similarly, other studies focusing on specific populations or geographical regions did not capture the broad picture of Canadian usage during this period. The RIVM report provided assumed usage frequencies due to a lack of available data. Studies focusing on increased eye injuries and poison center calls indicated a clear need to understand the elevated risks during the pandemic, especially concerning the increased exposure among children. This study addresses the significant gap in the literature by providing Canadian-specific data on hand sanitizer use among adults and children during the pandemic, with a particular emphasis on school/childcare settings.

This study employed two online surveys: one for the general population and another for teachers and childcare providers. The Dynata/Research Now Canada consumer panel provided a representative sample. The general population survey targeted Canadian adults (≥18 years) who had used hand sanitizer in the past six months. These adults were also asked about hand sanitizer use by children in their household. A second survey targeted teachers and childcare providers to assess children's hand sanitizer use in school/childcare settings. Surveys were available in English and French. Data collection spanned September 23 to October 9, 2021. The surveys collected demographic data, product type (gel, liquid, foam), dispenser type (pump, squeeze, spray), location of use, frequency of use, and amount used per application. Data analysis used Microsoft Excel 365 and R (v4.0.2) for descriptive statistics, visualizations, and comparisons. The Cochran-Mantel-Haenszel (CMH) test was employed using SAS to assess significant differences between home and school hand sanitizer use, adjusting for age.

The general population survey included 655 adults. Most (71%) reported increased hand sanitizer use during the pandemic compared to before. Overall, 65% used it up to 4 times/day, while 35% used it 5 or more times/day. The pump form was most commonly used. Among 231 adults with children in their homes, usage rates for children varied by age group. Children under 2 years old most frequently used it 0-3 times per day, while those aged 4–17 years used it 4 or more times/day, with 3.2% reporting 15–25 uses per day. The teacher/childcare provider survey included 298 teachers representing 7 age-grouped responses for children (4-17 years). The pump dispenser type was most often used in school/childcare settings (76.1%). In school/childcare settings, 45% reported hand sanitizer use of 4–6 times/day; 34% reported 7–25 times/day, with 17% reporting 10–25 times/day. Comparison of home and school use (4–17-year-olds) revealed statistically significant differences in frequency (p<0.0001), with higher school use, but no significant differences in the amount per use except a marginal difference for spray (p=0.04). The study also provided data on hand sanitizer use in children ≤3 years old, showing frequencies as high as 14 times/day in some cases. A comparison of pre-pandemic usage with the high school usage shows a 10-30 fold increase in exposure.

This study is the first known to provide Canadian-specific data on hand sanitizer use during the pandemic, including children's usage in school settings. The high usage rates observed, particularly among children in school/childcare, highlight the need to reassess exposure risks associated with hand sanitizer chemicals. The use of online surveys, while efficient, might introduce selection bias. The non-response from the Canadian territories might limit the generalizability of the findings. The reliance on observational data from parents and teachers introduces potential reporting bias. However, the study provides valuable real-world data that can be used to refine exposure assessments, particularly for children, who may be more vulnerable to the effects of the chemicals. The higher frequency of use in school versus at home is likely due to increased public health messaging and restricted access to handwashing facilities.

The study showed significantly higher daily hand sanitizer use during the pandemic compared to pre-pandemic levels for both adults and children. Children's usage was particularly high in school/childcare settings. The findings underscore the importance of incorporating this data into human health risk assessments of hand sanitizer chemicals. Future research should explore the long-term health effects of increased hand sanitizer exposure, particularly in vulnerable populations like children, and investigate more comprehensive data collection methods to minimize potential bias.

The reliance on self-reported data from online surveys introduces the potential for recall bias and response bias. The study did not collect data on income level, which could influence hand sanitizer usage patterns. The non-response from the Canadian territories limits the generalizability of the results to the entire Canadian population. Observational data on children from parents and teachers might be less precise than direct measurement of hand sanitizer usage. The study did not account for hand sanitizer use outside of home and school settings, potentially underestimating total daily usage for both children and adults.