Non – toxicity appreciate of ClO2
Many evaluations have shown ClO2 compounds to be non-toxic. Five decades of use have not indicated any adverse effects on health. The main areas of use have been disinfecting water supplies, the elimination of unwanted tastes and odors, and bleaching in the pulp and paper and textile industries. Toxicology tests include ingestion of ClO2 in drinking water, additions to tissue culture, injections into the blood, seed disinfection, insect egg disinfection, injections under the skin of animals and into the brains of mice, burns administered to over 1500 rats, and injections into the stalks of plants. “Standard Tests include, Ames Mutation, Chinese Hamster, Rabbits Eye, Skin Abrasion, Pharmacodynamics and Teratology.
In one tissue culture study, highly diluted DioxiDerm liquid was placed on CD4 cells infected with H.I.V. Viruses were inactivated inside the cell, as well as in the supernatant, and with little damage to the CD4 cell itself. Daughter cells 6 days later, although not as viable as the controls, were not infected. This is particularly impressive considering that most virucides are cytotoxic, even at high dilutions. Similar efficacy and non toxicity was demonstrated on infected cabbage seeds. 4000 seeds heavily infected with bacteria were soaked for about ½ hour in ClO2 disinfectant. No bacteria remained after this period, and the seeds then grew normally.
In order to reduce air and water pollution the EPA is proposing to substitute chlorine dioxide for the usual chlorine bleach in all pulp and paper mills throughout the country. This affects 350 installations and costs the industry about $4 billion.69 With a prospect of changing from chlorine to chlorine dioxide in our water supply, the EPA and American Water Works in the past have commissioned over 100 papers and studies on the toxicity of ClO2. Many controlled animal studies on the effects of ingesting sodium chlorite and chlorine dioxide have been conducted from 1 to 1000 mg/L concentrations. Metabolically, both ClO2 and ClO2¯ are rapidly reduced following ingestion. Radioactive chlorine tests show that most of the tagged chlorine is excreted from the urine in the form of Cl- ion with a small amount of ClO -. The no observed effect level, NOEL, from animal ingestion studies involving ClO2 and ClO2¯ , ranges to 100 ppm, about the concentration of Frontier’s DioxiDerm gel for topical use. The half life for the elimination of ClO2 and ClO2¯ from the plasma is less than half that of HOCl, hypochlorite.
In one study, human volunteers drank ClO2 or ClO2¯ in solution up to 24 ppm and showed no adverse effects. Several studies examined the effects on reproductive toxicity or teratology. There is no evidence of fetal malformation or birth defects at ClO2 concentrations, in drinking as well as skin route, up to 100 ppm. With prolonged feeding toxicity is produced mainly in the red blood cell. Rats fed up to 1000 mg/l chronically for 6 months showed no significant hematological changes. After 9 months, however, red blood cell counts, hematacrit and hemoglobin were decreased in all treatment groups.
Lack of toxicity on a long term, but low level basis is dramatically illustrated by two separate studies where rats,and honeybees, were fed ClO in high doses over a two year period. No ill effects were noted with up to 100 ppm added to water supply.
In a skin sensitization study, ClO2 liquid and gel (similar to DIOXIDERM ) were injected intradermally into guinea pigs, 10 times in about 3 weeks. No sensitivity reaction was observed. At the site of continuous liquid injection, necrotic areas developed due to the low pH of 2.7. This damage was reversible. The pH of Frontier’s DIOXIDERM GEL and DIOXIDERM
Liquid, however, is much higher at pH 4, and would probably avoid this temporary damage. An ocular irritation study in rabbits indicated redness in the conjunctivae after one hour, which became normal after 24 hours. The cornea and iris remained unchanged after treatment.
Fast disinfection and non-toxicity are properties normally not found side-by-side in the same compound. For example, formaldehyde and peracetic acid are strong and often used sterilants, but they are also toxic and irritating. Because both speeds of deactivation and non-toxicity are combined in DIOXIDERM biocides, new possibilities are opened for important skin products, as well as commercial surface disinfection.