Adverse Effects
Fluosilicic Acid
CAS No. 16961-83-4
 
 

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Activity: Wood Preservative
Structure:

Adverse Effects:
Bone
Dermal
Eye
Gastrointestinal tract

The major use of sodium hexafluorosilicate and fluorosilicic acid is as fluoridation agents for drinking water. Both chemicals are also used as a chemical intermediate (raw material) for aluminum trifluoride, cryolite (Na3AlF6), silicon tetrafluoride, and other fluorosilicates and have found applications in commercial laundry. Fluorosilicic acid is used in the tanning of animal hides and skins, in ceramics and glass, in technical paints, in oil well acidizing, in the manufacture of hydrogen fluoride, for the sterilization of equipment (e.g., in brewing and bottling establishments and for copper and brass vehicles), and in electroplating. It is also employed as an impregnating ingredient to preserve wood and harden masonry and for the removal of mold as well as rust and stain in textiles.
Fluorosilicic acid is mainly produced as a byproduct of the manufacture of phosphate fertilizers... In the manufacture of phosphate fertilizer in Central Florida, fluorides and radionuclides
(radium and uranium) are released as toxic pollutants.
During the acidulation process, radon gas can be released and carried into the fluorosilicic acid, while polonium can be captured during the
scrubbing process and combined with fluoride.

Ref: Toxicological Summary for Sodium Hexafluorosilicate [CASRN 16893-85-9] and Fluorosilicic Acid [CASRN 16961-83-4]. Review of Toxicological Literature. October 2001. Prepared for Scott Masten, Ph.D. National Institute of Environmental Health Sciences.
http://ntp-server.niehs.nih.gov/htdocs/Chem_Background/ExSumPDF/Fluorosilicates.pdf


Bone (click on for all fluorinated pesticides)

-- The effects of long-term exposure to fluorosilicic acid are changes in bone, corrosivity of the mucous membranes (e.g., ulceration of the nose, throat, and bronchial tubes), coughing, shock, pulmonary edema, fluorosis, coma, and even death (LCI, Ltd., undated-a). In a study of 50 workers engaged for approximately 30 years in the production of phosphate fertilizers, the concentration of gaseous fluoride (hydrogen fluoride, silicon tetrafluoride, and fluorosilicic acid) ranged from 0.04 to 0.17 mg/m 3 . Nine workers had increased bone densities (Fabbri et al., 1978; cited by HSDB, 2000a).
Ref: Sodium Hexafluorosilicate [CASRN 16893-85-9] and Fluorosilicic Acid [CASRN 16961-83-4]. Review of Toxicological Literature. October 2001. Prepared for Scott Masten, Ph.D. National Institute of Environmental Health Sciences P.O. Box 12233 Research Triangle Park, North Carolina 27709 Contract No. N01-ES-65402. Submitted by Karen E. Haneke, M.S. (Principal Investigator) Bonnie L. Carson, M.S. (Co-Principal Investigator) Integrated Laboratory Systems P.O. Box 13501 Research Triangle Park, North Carolina 27709.

http://www.fluoridealert.org/pesticides/Fluorosilicates.NIH.2001.pdf

Dermal (click on for all fluorinated pesticides)

-- Rats, guinea pigs, and swine tested as a group; no other data were provided, percutaneous; The intact skin was not affected. When areas were injured before application of the acid, necrosis, continuously spreading, occurred in the deeper regions. Hypocellular necrosis, consisting of sharp leukocyte demarcations, and edema up to the subcutis were observed. Alhassan and Zink (1982; cited by HSDB, 2000a)
-- Rabbits, New Zealand; 0.5 mL (4 mol) to the intact and abraded skin for 1, 24, or 72 h Severe erythema and edema were observed, indicating the material to be a primary irritant. Rhone- Poulenc Inc. (1971)
Ref: Review of Toxicological Literature. October 2001. Sodium Hexafluorosilicate [CASRN 16893-85-9] and Fluorosilicic Acid [CASRN 16961-83-4]. Prepared for Scott Masten, Ph.D. National Institute of Environmental Health Sciences P.O. Box 12233 Research Triangle Park, North Carolina 27709. Contract No. N01-ES-65402. Submitted by Karen E. Haneke, M.S. (Principal Investigator) Bonnie L. Carson, M.S. (Co-Principal Investigator) Integrated Laboratory Systems P.O. Box 13501 Research Triangle Park, North Carolina 27709.
http://www.fluoridealert.org/pesticides/Fluorosilicates.NIH.2001.pdf

Eye (click on for all fluorinated pesticides)

-- Rabbits, New Zealand, fluorosilicic acid (~ 23%, neat), purity n. p. instillation; 0.1 mL (0.8 mol) into the left eye. Eyes were observed at 24, 48, and 72 h following treatment. Severe and permanent corneal opacity with scar tissue occurred. Rhone- Poulenc Inc. (1971)
Ref: Review of Toxicological Literature. October 2001. Sodium Hexafluorosilicate [CASRN 16893-85-9] and Fluorosilicic Acid [CASRN 16961-83-4]. Prepared for Scott Masten, Ph.D. National Institute of Environmental Health Sciences P.O. Box 12233 Research Triangle Park, North Carolina 27709. Contract No. N01-ES-65402. Submitted by Karen E. Haneke, M.S. (Principal Investigator) Bonnie L. Carson, M.S. (Co-P
rincipal Investigator) Integrated Laboratory Systems P.O. Box 13501 Research Triangle Park, North Carolina 27709.
http://www.fluoridealert.org/pesticides/Fluorosilicates.NIH.2001.pdf

Gastrointestinal tract (click on for all fluorinated pesticides)

-- Rats, oral; 430 mg/ kg (LD 50 ; 2.98 mmol/ kg); Somnolence and/ or general depressed activity was observed. RTECS* (2000)
-- Rats, Sprague- Dawley albino, oral (via stomach tube); single doses of 215, 464, 1000, and 2100 mg/ kg (1.49, 3.22, 6.939, and 14.57 mmol/ kg) dissolved in water. Animals were observed for 14 days and then necropsied. With 464 mg/ kg, 3 out of 5 rats died; at 1000 mg/ kg, 100% mortality was observed. At 464 mg/ kg, acute depression was observed. Necropsy showed that animals in the low- dose group were "grossly normal" and that dead rats had massive hemorrhages in the entire gastrointestinal tract. Rhone- Poulenc Inc. (1971)
Ref: Review of Toxicological Literature. October 2001. Sodium Hexafluorosilicate [CASRN 16893-85-9] and Fluorosilicic Acid [CASRN 16961-83-4]. Prepared for Scott Masten, Ph.D. National Institute of Environmental Health Sciences P.O. Box 12233 Research Triangle Park, North Carolina 27709. Contract No. N01-ES-65402. Submitted by Karen E. Haneke, M.S. (Principal Investigator) Bonnie L. Carson, M.S. (Co-Principal Investigator) Integrated Laboratory Systems P.O. Box 13501 Research Triangle Park, North Carolina 27709.

http://www.fluoridealert.org/pesticides/Fluorosilicates.NIH.2001.pdf

 
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