Reported in EPA TSCA Inventory.

OSHA PEL: TWA 2.5 mg(F)/m³
ACGIH TLV: TWA 2.5 mg(F)/m³; BEI: 3 mg/g creatinine of fluorides in urine prior to shift; 10 mg/g creatinine of fluorides in urine at end of shift.
NIOSH REL: TWA (Inorganic Fluorides) 2.5 mg(F)/m³
DOT Classification:  6.1; Label: KEEP AWAY FROM FOOD

Potassium hexafluorosilicate(CAS NO.16871-90-2) has the synonyms of Potassium fluosilicate; Potassium silicofluoride; Silicate(2-), hexafluoro-, dipotassium; Silicate(2-), hexafluoro-, potassium (1:2). has weak oxidizing or reducing powers. Redox reactions can however still occur. The majority of compounds in this class are slightly soluble or insoluble in water. If soluble in water, then the solutions are usually neither strongly acidic nor strongly basic. These compounds are not water-reactive. Potassium hexafluorosilicate is mainly used for the preservation of timber, ceramics manufacturing, aluminum and magnesium smelting,optical glass manufacturing,etc.

You can still convert the following datas into molecular structure:
(1)InChI=1S/F6Si.2K/c1-7(2,3,4,5)6;;/q-2;2*+1;
(2)InChIKey=UUHPPUWEDCVPCO-UHFFFAOYSA-N;
(3)Smiles[Si-2](F)(F)(F)(F)(F)F.[K+].[K+];

The toxicity data is as follows: