Where It Comes From
Made on-site at water treatment plants and pulp/paper mills for disinfection and bleaching; breaks down to chlorite and chlorate [1][3].
How You Are Exposed
Workers may inhale it during water treatment, food sanitation, or pulp/paper bleaching; the public may encounter very low levels in tap water (within EPA limits) or from misuse of products [1][2][4].
Why It Matters
Short-term exposure causes cough, throat irritation, chest tightness; high levels can injure lungs. Swallowing strong solutions can cause vomiting, diarrhea, and red blood cell changes; children may be more sensitive [1][2][3].
Who Is at Risk
Workers; people with asthma or other lung disease; infants and young children [1][2][3].
How to Lower Your Exposure
At work, use ventilation, monitoring, and PPE; follow the NIOSH 0.1 ppm ceiling. Do not drink chlorine dioxide products; use water that meets EPA standards (MRDL 0.8 mg/L; chlorite MCL 1.0 mg/L) [2][1][4].
References
- [1]ATSDR. ToxFAQs for Chlorine Dioxide & Chlorite. Agency for Toxic Substances and Disease Registry.
- [2]CDC/NIOSH. Pocket Guide to Chemical Hazards: Chlorine dioxide (ClO2).
- [3]WHO. Guidelines for Drinking-water Quality (sections on chlorine dioxide, chlorite, and chlorate).
- [4]EPA. National Primary Drinking Water Regulations (MRDL for chlorine dioxide; MCL for chlorite).