Ammonium silicofluoride
CAS No. 16919-19-0

Return to Ammonium silicofluoride Adverse Effects

ACTIVITY: Insecticide, Miticide, Wood Preservative (Inorganic). US EPA List 3 Inert


Adverse Effects:

Body Weight Decrease


Environmental Effects:

Appendix 1 Hazardous Polluting Substance. 1978 Agreement between Canada and the US on Great Lakes Water Quality.

Regulatory Information
(only comprehensive for the US)
US EPA Registered: Yes.
EPA List 3 Inert 
US EPA PC Code: 075301
California Chemical Code 695
Registered Use in: US
Other Information
Molecular Formula:


Manufacturer:  Elf Atochem 
Other Names:
Ammonium fluosilicate
Ammonium Hexafluorosilicate
Fluorosilicic acid salts
Ammonium fluorosilicate [UN2854] [Poison]
Ammonium silicofluoride

Silicate(2-), hexafluoro-, diammonium
Ammonium silicon fluoride
Caswell No. 043
Diammonium fluosilicate
Diammonium fluosilicate ((NH4)2SiF6)
Diammonium hexafluorosilicate
Diammonium hexafluorosilicate(2-)
Diammonium silicon hexafluoride
EINECS 240-968-3
Fluorosilicic acid, ammonium salt
HSDB 472

NSC 310005
Silicate, hexafluoro-, diammonium
Of special interest:
PAN Data
TOXNET profile from Hazardous Substances Data Bank
August 12, 2005 - Report of toxic spill at Phillips plant not needed. By Nik Bonopartis. Poukeepsie Journal (NY).
... Gerald Sliss is a former IBM senior engineering specialist at the East Fishkill site. The plant has had similar problems with releases of chemicals and with maintenance of the exhaust systems dating back to when it was owned by IBM. The exhaust systems, he said, did not have "scrubbers" to clean air ducts until employees began filing complaints with OSHA.
"The exhaust systems were corroding and guys were getting stuff literally dripping down on them," said Sliss, who was laid off by IBM in 1993 after 24 years. Sliss has done some work at the site after 1993 while working for third-party vendors who supplied materials for the manufacturing process
Sliss said despite advances in technology, manufacturing companies haven't found efficient and safe ways to handle and remove chemical byproducts.
"This is an industry-wide problem," he said. "The problem is the whole process is dirty and always has been."
August 4, 2005 - Powdery chemical covers cars in East Fishkill. Philips plant emitted substance. By Nik Bonopartis. Poughkeepsie Journal (NY).
... The "spill" happened on July 7 at the East Fishkill IBM and Philips Semiconductor campus, according to internal documents from IBM and Philips. About 80 cars belonging to employees of Philips and IBM were coated with the chemical compound... The chemical was re-leased during a maintenance project on exhaust ducts in the Philips manufacturing plant, Philips spokesman Paul Morrison said... There is some confusion about how much ammonium fluorosilicate constitutes "reportable levels." Morrison did not say exactly how much was released, and the DEC could not say how much of the chemical would need to be released before it was considered an environmental hazard. ..
In Australia: Used as an adjuvant for silica gel insecticide.
Ref: June 2002. Table 5. Uses of substances where maximum residue limits are not necessary. Australian National Registration Authority for Agricultural Veterinary Chemicals. The MRL Standard. Maximum residue limits in food and animal feedstuff.
Material Safety Data Sheet - from LCI, Ltd., Jacksonville Beach, FL 32240-9000
June 21, 2001 - Hazardous Materials Regulations for Fluoride/fluorinated substances. Federal Register on Harmonization of international shipment of Dangerous Goods. Final Rule.
2000 - Hazardous Substance Fact Sheet - NJ Dept. of Health and Senior Serivices
1982 - Mothproofing agent: Eradication of insects from wool textiles by Barbara Reagan. JAIC 1982, Volume 21, Number 2, Article 1 (pp. 01 to 34)
1981-1983 National Exposure Survey. U.S. Estimated Percentages of Controlled and Uncontrolled Potential Exposures to Specific Agents by Occupation within 2-Digit Standard Industrial Classification (SIC). The highest exposures were to LAUNDERING AND DRY CLEANING MACHINE OPERATORS.
List of Inactive insecticide products

US EPA List of Inerts. This substance is on List 3.

Note: US EPA allows so-called "Inert" ingredients to be commonly mixed with the "active" pesticidal ingredient to create a formulated pesticide product. According to EPA, "The term `inert' is not intended to imply nontoxicity; the ingredient may or may not be chemically active." "Inert" ingredients include solvents, emulsifiers, spreaders, and other substances mixed into pesticide products to increase the effectiveness of the active ingredients, make the product easier to apply, or to allow several active ingredients to mix in one solution. Both US EPA and California Department of Pesticide Regulation require pesticide manufacturers to identify inert ingredients in their products but do not disclose this information to the general public because the pesticide industry considers product formulations trade secrets, protected by law and by the US EPA. The US EPA category of Inerts (as of September 2003):

List 1 - Of Toxicological Concern
List 2 - Potentially Toxic / High Priority for Testing
List 3 - Of Unknown Toxicity
List 4A - Generally Regarded as Safe
List 4B - EPA states it has Sufficient Information to Reasonably Conclude that the Current Use Pattern in Pesticide Products will not Adversely Affect Public Health or the Environment
List 4 (all) .

See good report: Toxic Secrets": "Inert" Ingredients in Pesticides 1987-1997, published by Northwest Coalition for Alternatives to Pesticides.


Source: Translation of Posobie diya opredeleniy; 110 pp., 1956


Bondarstsev AS

Abstract: HAPAB One chapter of this manual treats the prevention and control of woodrotting fungi. The toxicity of the usual water-soluble preservatives, sodium fluoride, is similar to that of silicofluoride and ammonium silicofluoride, and so all three require the same safety measures. The preservative oil, EAG-2 (concentrated emulsion of generator schist tar dissolved in caustic soda, with gas oil and sodium phosphate), is highly toxic to wood-rotting fungi, and its insecticidal activity is increased by adding hexachloran. It does, however, have a strong odor of schist tar which persists for 3-3 weeks and is most unpleasant for the workmen applying the preservative. Safety regulations for work with wood preservatives are listed: provision of sand, and fire equipment; use of overalls, gloves, protective footwear, goggles and respirators by operators; coating of hands and faces with protective creams; provision of water and first- aid equipment; and use of special instructions in the handling of preservatives. SAFETY 67/04/00, 47 1956

Related Chemicals:
Ref: Pesticide Action Network (PAN)
CAS No. Relation Chemical Name PAN & FAN data Some Notes from FAN:
16893-85-9 Parent * Sodium fluosilicate



US EPA List 3 inert

Registered in:
Australia, Canada, India, South Africa, Tanzania, Vietnam

UK: Cancelled

16919-19-0 Related (1)

Ammonium fluosilicate


US EPA List 3 inert

SYN: Ammonium silicofluoride

62449-69-8 Related (1) Ammonium fluosilicate on silica gel



SYN: Barium hexafluorosilicate
17125-80-3 Related (1)

Barium fluosilicate



Registered in: India

EU: Not allowed to be used as an active ingredient after July 25, 2003

SYN: Barium hexafluorosilicate

12062-24-7 Related (1)

Cupric fluosilicate



Copper silicofluoride,
Cupric hexafluorosilicate
1327-43-1 Related (1) Magnesium aluminum fluosilicate



US EPA List 3 inert  
16949-65-8 Related (1) Magnesium fluosilicate



53404-77-6 Related (1) Sodium aluminum fluosilicate



16871-71-9 Related (1)

Zinc fluosilicate



PAN Bad Actor Chemical:
Developmental or Reproductive Toxin

SYN: Zinc silicofluoride

Explanation from PAN:
* Parent: Compounds labeled with a "P" are the parent compound of the group. The parent chemical was chosen on the basis of available toxicity information, where chemicals with the maximum amount of toxicity information assigned to parent status. Where no toxicity information was available for any member of a group, we assigned parent status to the least derivatized member of the group for organic compounds (e.g., benzoic acid would be the parent instead of methyl benzoate), the sodium salt (for compounds with a common anion), or the chloride salt (for compounds with a common cation). These are general guidelines and not hard and fast rules, because the groups are rarely so easy to categorize. For some groups with no obvious parent, assignment of parent status was arbitrary.

Group 1: Salts, esters and/or complexes of the parent chemical, e.g., glyphosate and glyphosate, isopropylamine salt; 2,4-D and 2,4-D, butoxyethyl ester. Alternatively, the parent compound itself is an ester or salt, and related compounds are other esters or salts.


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