Abstract / Summary
Abstract Background Domestic chlorine gas exposures, resulting from the mixing of hypochlorite-based products with acidic products, are a recognised public health issue. However, national evidence on factors associated with severity and long-term trends remains limited. We aimed to identify factors associated with severity of domestic chlorine gas exposures in France in 2023 and to analyse temporal trends over 16 years (2010–2025). Methods We conducted a national retrospective study combining an individual-level cross-sectional analysis of cases from 2023 with an aggregate 16-year temporal trend analysis, using data from the French national poison control centre (PCC) database. Binary logistic regression identified factors independently associated with moderate-to-severe poisoning (Poisoning Severity Score ≥ 2) among symptomatic cases from 2023. Annual data for 2010–2025 were expressed as a standardised index (base 100, reference year 2010) and analysed using segmented regression to detect changes in trend. Results In 2023, 1,829 cases were recorded, of which 280 (17.1% of symptomatic cases) were moderate-to-severe, including 11 severe and 2 fatal poisonings. Obstructive airway disease (aOR 3.65, 95% CI 2.64–5.01), older age (aOR 1.25 per 10-year increment, 95% CI 1.15–1.35), and active smoking among individuals with no reported respiratory history (aOR 3.22, 95% CI 2.25–4.58) were associated with severity. The standardised index increased over the study period, with a breakpoint around 2018 after which the annual increase more than doubled (+ 12.25 vs. + 4.97 points/year), coinciding with a marked rise in PCC-recorded cases involving vinegar rather than bleach. Conclusions Although uncommon, severe and fatal domestic chlorine gas poisonings from household product mixing occurred in 2023, highlighting the continuing public health relevance of these exposures. Obstructive airway disease, older age, and active smoking were independently associated with severity. PCC-recorded poisoning cases also increased substantially over 16 years, coinciding with a marked rise in cases involving vinegar rather than bleach. This pattern is consistent with growing use of vinegar alongside bleach as a perceived natural cleaning product. These findings support more visible, targeted prevention messaging and further investigation of the potential long-term respiratory consequences of recurrent, clinically minor exposures. Clinical trial number Not applicable.