Chlorine dioxide, chlorite and chlorate History of Guideline Development ~WHO
****!!!!**** "guidelinevalue for chlorine dioxide was not needed as chlorine dioxide is reduced primarily to chlorite, chlorate and chloride in drinking-water, and to chlorite and chloride upon ingestion"
Technical Report: Sodium Chlorite, for Generation of Chlorine Dioxide Gas--Handling/Processing ~National Organic Program, USDA
****2018 Jan. {Very good technical info. Fumigation leaves no CD or by-product residue. Air treatments are more effective than Liquid. Includes several CD and SC trade names. Denied because of lack of public requests, available alternatives, etc.}
WHO~ Concise International Chemical Assessment Document 37: Chlorine Dioxide (Gas) ~WHO
***!!!!**** 2002 " Some studies have been conducted via the oral route using aqueous solutions of chlorine dioxide. Several of these studies were conducted using “stabilized aqueous chlorine dioxide,” sometimes by maintaining a constant pH using sodium carbonate and sodium hydrogen carbonate. However, it is recognized that this would effectively lead to the formation of aqueous sodium chlorite (which can subsequently generate chlorine dioxide by acid dis-placement). These studies are felt to be less relevant than those using stabilized aqueous chlorine dioxide and are not summarized in this review. The reasons for this are that chlorine dioxide dissolves discretely in water (i.e., it does not dissociate into ions), forming a solution of around pH 5 or less, whereas an aqueous solution of sodium chlorite has a different, ionized composition and a pH of approximately 8. The explosive nature of this substance has limited the concentration of chlorine dioxide in aqueous solutions to a maximum of about 1% w/v"
{******pg 4 -- ppm conversion info for air concentrations:} "0.1 ppm (0.28 mg/m3) 8-h time-weighted average (TWA) and 0.3 ppm (0.84 mg/m3) 15-min reference period" "It is predicted thatdermal exposure from contact with the aqueous solution in occupational settings will range from 0.1 to 5 mg/cm2 per day" "There are no quantitative human data, but chlorine dioxide is very toxic by single inhalation exposure in rats. There were no mortalities following exposure to 16 ppm (45 mg/m3) for 4 h, although pulmonary oedema and emphysema were seen in all animals exposed to 16–46 ppm (45–129 mg/m3) chlorine dioxide,the incidence increasing in a dose-related manner. The calculated mean LC50 was 32 ppm (90 mg/m3). In another study, ocular discharge, nosebleeds, pulmonary oedema, and death occurred at 260 ppm (728 mg/m3) for 2 h. Chlorine dioxide is toxic when administered in solution by a single oral dose to rats; at 40 and 80 mg/kg bodyweight, there were signs of corrosive activity in the stomach and gastrointestinal tract. The calculated oral LD50 was 94 mg/kg body weight."
{ToxProf docs: Core document} Toxicological Profile for Chlorine Dioxide and Chlorite ~ATSDR
2004 Sept. ********No reports were located in which gastrointestinal, musculoskeletal, endocrine, dermal, or metabolic effects were associated with inhalation exposure of humans or animals to chlorine dioxide or chlorite. *******Example concentrations: 150 ppm (420 mg/m3), 10 ppm (28 mg/m3), etc. {Contact info for Association of Occupational and Environmental Clinics (AOEC) & American College of Occupational and Environmental Medicine (ACOEM)}
{EPA RED docs for *Chlorine*} - *Chlorine* Reregistration Evaluation Decision RED materials
1992 "The loose term 'chlorine' is generally used by the industry to mean 'available chlorine' and 'residual chlorine' to refer to hypochlorous acid." "In solution, chlorine gas and sodium hypochlorite produce the same active ingredient, hypochlorous acid."
{EPA RED docs: Memo re. chlorine} Memo re. **Chlorine** Product and Residue Chemistry Chapters for the RED ~EPA
1994 {This doc was used for work on Chlorine Dioxide/SC RED decisions} "...has decided to uphold the current exemption from requirements for a tolerance for *chlorine* residues resulting from preharvest and posthavest uses on all raw agricultureal commodities."
{EPA RED docs: Core 2006 decision} Reregistration Eligibility Decision (RED) for Chlorine Dioxide and Sodium Chlorite (Case 4023) ~EPA
2006 Aug. "Readers are referred to USEPA (2000a) for a detailed review of the effects seen at specific concentrations and exposure durations along with the derivation of the RfC."
WHO~ Chlorine Dioxide, Chlorite and Chlorate in Drinking Water--Background document for development of WHO Guidelines for Drinking Water Quality ~WHO
**** 2017 Jan. "Any chlorine dioxide remaining at the consumer’s tap will be reduced to chlorite and chloride upon ingestion. *** Consequently, a guideline value for chlorine dioxide has not been established."..."For chlorite, JECFA established an ADIof 0–0.03mg/kg bw on the basis of the NOAEL of 3mg/kg bw per day...Using the upper bound of the chlorite ADI of 30 μg/kg bw, a typical human body weight of 60 kg, the assumption that drinking-water contributes80% of the total exposure and a typical consumption of 2 L of water per day, the provisional guideline value is calculated to be 0.7mg/L (rounded figure). This guideline value is designated as provisional because use of chlorine dioxide as a disinfectantmay result in the chlorite guideline value being exceeded, " "JECFA therefore established an ADIof 0–0.01 mg/kg bw for chlorate" "[Page 1] Conversion factor in air: 1 part per million (ppm) = 2.8 mg/m3"
