title: Aquatic toxicity assessment of phosphate compounds.
abstract: OBJECTIVE
  Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment.
  
  
  METHODS
  An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data.
  
  
  RESULTS
  THE RESULTS OF THE ECOTOXICITY TESTS OF TRICALCIUM PHOSPHATE AND CALCIUM HYDROGENORTHOPHOSPHATE ARE AS FOLLOWS: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration (LC(50)) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration (EC(50)) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr EC(50) was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively.
  
  
  CONCLUSIONS
  Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, L(E)C(50) was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth.
authors: Risk Assessment Division, National Institute of Environmental Research, Incheon, Korea.
authors: Eunju
authors: E
authors: Kim
authors: Sunkyoung
authors: S
authors: Yoo
authors: Hee-Young
authors: HY
authors: Ro
authors: Hye-Jin
authors: HJ
authors: Han
authors: Yong-Wook
authors: YW
authors: Baek
authors: Ig-Chun
authors: IC
authors: Eom
authors: Hyun-Mi
authors: HM
authors: Kim
authors: Pilje
authors: P
authors: Kim
authors: Kyunghee
authors: K
authors: Choi
keywords: Acute toxicity test; Eutrophication; Phosphate; Risk assessment