Causes severe irritation and burns. May be harmful if swallowed. Avoid breathing vapor or dust. Use with adequate ventilation. Avoid contact with eyes, skin, and clothes. Wash thoroughly after handling. Keep container closed.

Tetrasodium pyrophosphate, also called sodium pyrophosphate or tetrasodium phosphate, is a slightly toxic and mildly irritating colorless transparent crystalline chemical compound with the formula na4p2o7. It contains the pyrophosphate ion. Toxicity is approximately twice that of table salt when ingested orally.