Occupational Health Effects of Chlorine Spraying in Healthcare Workers: A Systematic Review and Meta-Analysis of Alternative Disinfectants and Application Methods

Abstract

Chlorine spraying was widely used during filovirus outbreaks, but concerns about occupational health risks led to a shift toward wiping. This systematic review aimed to evaluate the health risks associated with exposure to disinfectants among healthcare workers (HCWs), with a specific focus on chlorine-based products and spraying compared to alternative disinfectants and general disinfection tasks (GDTs). PubMed, Embase, and Scopus were searched from inception to March 2025. Eligible studies included observational or experimental research on HCWs exposed to chemical disinfectants. Two reviewers independently screened studies, assessed the risk of bias using a validated occupational health tool, and evaluated evidence certainty with the GRADE approach. Meta-analyses used fixed- and random-effects models; heterogeneity was assessed with I² statistics. Out of 7154 records, 29 studies were included. Most studies were cross-sectional with a high bias risk. Odds ratios (ORs) were calculated using non-exposed groups as reference. Significant associations with respiratory conditions were found for chlorine-based products (OR 1.71), glutaraldehyde (OR 1.44), spraying (OR 2.25), and GDTs (OR 2.20). Exposure to chlorine-based products, glutaraldehyde, spraying, and GDTs likely increases respiratory risk in HCWs, as supported by moderate-certainty evidence. These findings support prioritizing safer disinfectants and strengthening protective measures over banning specific application methods.

Keywords: disinfectants; health personnel; occupational health; respiratory disorders.

Figure 1

Flow diagram of literature search and selection criteria adapted from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (adapted from Moher et al. [23]).

Figure 2

Meta-analysis of the association between disinfectants and respiratory conditions. (a) Forest plot of studies examining the association between exposure to chlorine-based products and respiratory conditions compared to a non-exposed group [28,32,35,37,44,46,50,51]. (b) Forest plot of studies assessing the association between glutaraldehyde exposure and respiratory conditions compared to a non-exposed group [32,37,44,50]. (c) Forest plot of studies examining the association between exposure to quaternary ammonium compounds (QACs) and respiratory conditions compared to a non-exposed group [32,37,46,50,51]. (d) Relative odds ratios (RORs) comparing the respiratory effects of glutaraldehyde and QACs to chlorine-based products. Blue diamond indicates the pooled OR from the common (fixed) effect model; red diamond indicates the pooled OR from the random effects model. Chlorine-based products and glutaraldehyde showed statistically significant associations with increased respiratory risk. The association for QACs was not statistically significant and showed high heterogeneity. OR, odds ratio; CI, confidence interval; ROR, relative odds ratio; QACs, quaternary ammonium compounds.

Figure 3

Meta-analysis of the association between disinfection methods and respiratory conditions. (a) Forest plot of studies examining the association between the use of spraying disinfectants and respiratory conditions compared to a non-exposed group [28,37,42,44,50]. (b) Forest plot of studies assessing the association between general disinfection tasks (e.g., wiping, mopping) and respiratory conditions compared to a non-exposed group [25,28,42,50]. (c) Relative odds ratios (RORs) comparing the respiratory effects of general disinfection tasks to spraying disinfectants. Blue diamond indicates the pooled OR from the common (fixed) effect model; red diamond indicates the pooled OR from the random effects model. Both spraying and general disinfection tasks were significantly associated with increased odds of respiratory conditions. The comparison between the two methods showed no significant difference. OR, odds ratio; CI, confidence interval; ROR, relative odds ratio.