National Toxicology Program

Selected toxicity information from HSDB, one of the National Library of Medicine's databases. ¹

Names (NTP)

• CHLORIC ACID, SODIUM SALT (8CI((9CI)
• SODIUM CHLORATE (WATER DISINFECTION BYPRODUCTS)
• ATLACIDE
• Sodium chlorate
• Water disinfection byproducts (Sodium chlorate)

Human Toxicity Excerpts

• IN CHLORATE POISONING: HEINZ BODIES ARE OFTEN PRESENT AND ... MANY OF THE ERYTHROCYTES CLUMP AND ARE BROKEN UP. LATTER EFFECT PRODUCES EMBOLI AND EXCRETION OF BLOOD PIGMENTS BY KIDNEY, WITH RESULTING DARK-COLORED URINE. /CHLORATES/ [Thienes, C., and T.J. Haley. Clinical Toxicology. 5th ed. Philadelphia: Lea and Febiger, 1972., p. 158]**PEER REVIEWED**
  
• DEATH /FROM CHLORATE POISONING/ OCCURS WITHIN A FEW HR TO FEW DAYS. ... DEATH IS DUE TO SEVERE METHEMOGLOBINEMIA OR TO ACUTE NEPHRITIS. /CHLORATES/ [Thienes, C., and T.J. Haley. Clinical Toxicology. 5th ed. Philadelphia: Lea and Febiger, 1972., p. 159]**PEER REVIEWED**
  
• CAUSES SKIN IRRITATION & ULCERATION OF NASAL SEPTUM. ORAL INGESTION MAY PRODUCE ABDOMINAL PAIN, NAUSEA, VOMITING, DIARRHEA, PALLOR, BLUENESS, SHORTNESS OF BREATH, UNCONSCIOUSNESS & COLLAPSE. [Weed Science Society of America. Herbicide Handbook. 5th ed. Champaign, Illinois: Weed Science Society of America, 1983., p. 443]**PEER REVIEWED**
  
• 13 YR OLD BOY INGESTED WHITE CRYSTALS, 6 HR LATER HE BECAME ILL WITH RIGORS, ABDOMINAL PAIN, VOMITING & DIARRHEA. URINE WAS DARK WITH BLOOD CLOTS. 3 DAYS LATER RENAL FAILURE WAS PRESENT. [STARVOU A ET AL; PRACTITIONER 221 (1323): 397-9 (1978)]**PEER REVIEWED**
  
• Sodium chlorate and potassium chlorate ... are potent oxidants, and accidental or intentional ingestion has resulted in fatal methemoglobinemia as well as hemolysis. They are also toxic to GI tract, liver and kidney. [Haddad, L.M., Clinical Management of Poisoning and Drug Overdose. 2nd ed. Philadelphia, PA: W.B. Saunders Co., 1990., p. 302]**PEER REVIEWED**
  
• A 29 year old man ingested about 20 g of sodium chlorate (230 mg chlorate/kg body weight). He became cyanotic, and his hemoglobin dropped to 11 g/100 ml within 24 hr; methemoglobin and methemoalbumin were detected in his plasma. He was anuric for 14 days, then gradually improved, and he was released from the hospital after 6 wk. [National Research Council. Drinking Water and Health. Volume 7. Washington, DC: National Academy Press, 1987., p. 102]**PEER REVIEWED**
  
• 14 cases of sodium chlorate poisoning was reported. The patients' ages ranged from 3 to 55 years. Doses estimated to be in excess of 100 g or 79 g as chlorate ion were uniformly fatal. One 46 year old woman given supportive therapy died 20 hours after a dose estimated to be 15 g (218 mg chlorate/kg body wt). This was the lowest dose found to be fatal in these cases. Another female of unreported age died 5 days after ingesting 30 g (436 mg chlorate/kg body weight) despite treatment with methylene blue, peritoneal dialysis, and exchange transfusion. However, an 18 yr old male survived a dose estimated at 100 g (1.45 g chlorate/kg body wt) after treatment with methylene blue, exchange transfusion, and hemodialysis. Cyanosis was seen in 50% of the patients, abdominal pain in 36%, diarrhea in 21%, dyspnea in 21%, anuria within 48 hr in 50%, coma in 12%, and methemoglobinemia in 93%, 64% died. [National Research Council. Drinking Water and Health. Volume 7. Washington, DC: National Academy Press, 1987., p. 102]**PEER REVIEWED**
  
• Ingestion of relatively large quantities may be fatal. [Weed Science Society of America. Herbicide Handbook. 5th ed. Champaign, Illinois: Weed Science Society of America, 1983., p. 443]**PEER REVIEWED**
  
• ... Near-fatal poisoning occurred when a 13 year old boy "tasted" crystals of /sodium chlorate/ which he found in his father's shed. In spite of intensive treatment, recovery did not begin until about the 15th day and required a little over 40 days. [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc., 1991., p. 565]**PEER REVIEWED**
  
• Poisoning is characterized by gastritis (nausea, vomiting, and pain), anoxia, (cyanosis, collapse, and terminal convulsions) secondary to methemoglobinemia, possible liver injury, and nephritis (lumbar pain and oliguria). Nephritis presumably is the direct result of chlorate ion as well as secondary to the destruction of corpuscles. The blood pressure tends to fall and the heartbeat becomes irregular. The liver and spleen may be enlarged and tender. The urine, if any, is brown or black in color and contains casts, red cells, free hemoglobin, and methemoglobin. The blood is brownish in color, and the plasma contains free hemoglobin and free methemoglobin. The red cell count is very low and the white cell count high. Onset may be delayed as much as 12 hr. Death from sodium chlorate poisoning has occurred from 4 hr to 34 days after ingestion with an average of just over 4 days. [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc., 1991., p. 566]**PEER REVIEWED**
  
• Dermal absorption associated with agricultural use of sodium chlorate is not sufficient to cause systemic poisoning. Even by mouth, a large dose is required to produce illness. [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc., 1991., p. 566]**PEER REVIEWED**
  
• Sodium chlorate is a powerful oxidizing agent that causes methemoglobinemia, hemolytic anemia, and direct nephrotoxic effects. Coma and death within a few hr can result from either tissue hypoxia (severe methemoglobinemia), hyperkalemia from massive hemolysis, or acute renal failure compounded by hemoglobinuria. ... Within 2-24 hr, GI symptoms develop including nausea, vomiting, diarrhea, and abdominal pain. After absorption, hemoglobin rapidly oxidizes to methemoglobin, leading to cyanosis, dyspnea, and coma in severe cases. Intravascular hemolysis also can occur. [Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997., p. 1642]**PEER REVIEWED**
  
• Swallowing solution or solid results in nausea, vomiting, and abdominal pain, and possibly kidney damage. [Armour, M.A. Hazardous Laboratory Chemicals Disposal Guide. Boca Raton, FL: CRC Press Inc., 1991., p. 380]**PEER REVIEWED**
  

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Non-Human Toxicity Excerpts

• ALTHOUGH THE CAUSE OF DEATH FROM INGESTION ... SEEMS TO BE THE FORMATION OF METHEMOGLOBIN WITH CONSEQUENT TISSUE ANOXIA, THE RATE OF FORMATION OF METHEMOGLOBIN FROM HEMOGLOBIN IS RELATIVELY SLOW ... AND OTHER SIGNS USUALLY PRECEDE THE CYANOSIS AND DYSPNEA ASSOCIATED WITH METHEMOGLOBINEMIA. THESE ARE STAGGERING, PURGING, EVIDENCE OF ABDOMINAL PAIN, HEMOGLOBINURIA, AND HEMATURIA ... IN ACUTE POISONING /BY INGESTION OF/ LARGE AMOUNTS. ... DEATH MAY OCCUR SUDDENLY WITHOUT OBVIOUS SYMPTOMS. IN SUCH CASES, THE HISTORY OF SUDDEN DEATH, TOGETHER WITH THE APPEARANCE OF "TARRY" BLOOD EXUDING FROM NOSTRILS, ANUS AND VULVA, MAY LEAD TO CONFUSION WITH ANTHRAX. [Clarke, M. L., D. G. Harvey and D. J. Humphreys. Veterinary Toxicology. 2nd ed. London: Bailliere Tindall, 1981., p. 39]**PEER REVIEWED**
  
• ... POISONING OF 15 CATTLE WITH 6 DEATHS /WAS RECORDED/ FOLLOWING APPLICATION OF ... SODIUM CHLORATE TO ... A FIELD. IN ANOTHER CASE, 2 CATTLE DIED AND OTHERS SHOWED SYMPTOMS AFTER APPROXIMATELY 0.4 KG OF SODIUM CHLORATE HAD BEEN SCATTERED ONTO A PASTURE TO KILL THISTLES. SODIUM CHLORATE SPRAYS SEEM TO HAVE LOWER TOXICITY FOR SHEEP THAN FOR CATTLE, FOR NO HARMFUL EFFECTS WERE OBSERVED IN SHEEP GRAZING PLOTS, HEAVILY SPRAYED WITH HERBICIDE, OVER A PERIOD OF 7 DAYS. [Clarke, M. L., D. G. Harvey and D. J. Humphreys. Veterinary Toxicology. 2nd ed. London: Bailliere Tindall, 1981., p. 38]**PEER REVIEWED**
  
• SODIUM CHLORATE SHOWED ORAL LD OF ABOUT 2 G/KG IN DOGS. ORAL DOSE OF 1 G/KG RESULTED IN SEVERE METHEMOGLOBINEMIA & DEATH OF ANOTHER DOG WITH PRE-EXISTING CHRONIC INTERSTITIAL NEPHRITIS. [SHEAHAN BJ ET AL; RES VET SCI 12 (4): 387-9 (1971)]**PEER REVIEWED**
  
• TOXICITY OF CHLORATE TO DOMESTIC ANIMALS: HORSE 250 G LETHAL; COW 500 G LETHAL; CALF 260 MG/KG NO EFFECT; CALF 525 MG/KG NO EFFECT; COW 0.1-0.25 G/KG FOR 5 DAYS DARK BROWN URINE, METHEMOGLOBINEMIA. TOXICITY OF CHLORATE FOR DOMESTIC ANIMALS: COW 0.06-0.18 G/KG FOR 3 DAYS ANOREXIA, WATERY FECES, COW WENT DOWN; SHEEP 10 G OR MORE PRODUCES METHEMOGLOBINEMIA; CHICKEN 5 G/KG LETHAL; DOGS 0.5-2.0 G/KG LD50 IN 2-4 DAILY DOSES. [BUCK ET AL; CLINICAL AND DIAGNOSTIC VETERINARY TOXICOLOGY, 2ND ED, 167-8 (1976)]**PEER REVIEWED**
  
• Phytotoxic to all crops. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987., p. A294/Aug 87]**PEER REVIEWED**
  
• The minimum lethal dose is of the order of 1 g/kg body wt in cattle, 1.5-2.5 g/kg body wt in sheep, and 5 g/kg body wt in poultry. ... Although the cause of death following chlorate ingestion appears to be the tissue anoxia resulting from methemoglobinaemia, the rate of methemoglobin formation is relatively slow and other signs usually precede cyanosis and dyspnea. These include staggering, purging, evidence of abdominal pain, hemoglobinuria, and hematuria. In acute chlorate poisoning, death may occur suddenly, without development of obvious clinical signs. In such cases, the history of sudden death, together with the appearance of 'tarry' blood exuding from the nostrils, anus, and vulva, may lead to confusion with anthrax. ... The post-mortem changes associated with chlorate poisoning include a characteristic dark, chocolate brown colored blood, with more or less pronounced brownish discoloration of the organs and tissues. In chlorate poisoning, methemoglobin formation continues after death. [Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988., p. 29]**PEER REVIEWED**
  
• Poisoned dogs showed post mortem evidence of marked splenic congestion and moderately severe chronic interstitial nephritis. Peak blood methemoglobin levels occurred 1 hr following iv administration of 0.5 g/kg body wt of sodium chlorate, while in animals which died the values were still rising 5 hr after sodium chlorate administration. [Humphreys, D.J. Veterinary Toxicology. 3rd ed. London, England: Bailliere Tindell, 1988., p. 30]**PEER REVIEWED**
  

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Human Toxicity Values

• Death invariably follows a dose of 100 g. [Ellenhorn, M.J. and D.G. Barceloux. Medical Toxicology - Diagnosis and Treatment of Human Poisoning. New York, NY: Elsevier Science Publishing Co., Inc. 1988., p. 1097]**PEER REVIEWED**
  

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Non-Human Toxicity Values

• LD50 Rat oral 1200 mg/kg [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982., p. 61]**PEER REVIEWED**
  
• LD50 Mouse ip 596 mg/kg [Hayes, W.J., Jr., E.R. Laws, Jr., (eds.). Handbook of Pesticide Toxicology. Volume 2. Classes of Pesticides. New York, NY: Academic Press, Inc., 1991., p. 565]**PEER REVIEWED**
  
• LD50 Mouse oral 8350 mg/kg [Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2953]**PEER REVIEWED**
  
• LD50 Rabbit oral 7200 mg/kg [Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2954]**PEER REVIEWED**
  

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Absorption, Distribution and Excretion

• CHLORATES: ... ARE READILY ABSORBED FROM THE ALIMENTARY TRACT, BUT NOT FROM THESKIN. /CHLORATES/ [Thienes, C., and T.J. Haley. Clinical Toxicology. 5th ed. Philadelphia: Lea and Febiger, 1972., p. 158]**PEER REVIEWED**
  
• CHLORATE ... IS RAPIDLY EXCRETED UNCHANGED BY THE KIDNEYS, EXCRETION BEING COMPLETE IN 2 DAYS. /CHLORATES/ [Thienes, C., and T.J. Haley. Clinical Toxicology. 5th ed. Philadelphia: Lea and Febiger, 1972., p. 159]**PEER REVIEWED**
  
• IT IS READILY ABSORBED THROUGH BOTH ROOTS AND LEAVES AND MAY BE TRANSLOCATED THROUGHOUT PLANT. [White-Stevens, R. (ed.). Pesticides in the Environment: Volume 1, Part 1, Part 2. New York: Marcel Dekker, Inc., 1971., p. 35]**PEER REVIEWED**
  
• Absorbed through the roots and foliage, with translocation basipetally in the xylem, as the phloem tissue is killed. The rate of respiration is increased, catalase activity decreased, and the plant's food reserves are depleted. [Hartley, D. and H. Kidd (eds.). The Agrochemicals Handbook. 2nd ed. Lechworth, Herts, England: The Royal Society of Chemistry, 1987., p. A294/Aug 87]**PEER REVIEWED**
  

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Metabolism/Metabolites

• None found

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TSCA Test Submissions

• None found

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Footnotes

¹ Source: the National Library of Medicine's Hazardous Substance Database, 10/28/2007.