Trisodium nitrilotriacetate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.93 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.8 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.093 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

0.08 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

270 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:

no exposure of sediment expected

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no exposure of soil expected

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

PNEC Freshwater

Reliable long-term data was available for a fish, invertebrate and algae. The lowest NOEC of 9.3 mg/L was a result for testing with Gammarus pseudolimnaeus (Arthur et al. 1974). An assessment factor of 10 was used as per Part R.10 Guidance for a resulting PNEC for intermittent releases of 0.93 mg/L.

PNEC Marine

Reliable long-term data was available for a fish, invertebrate and algae for freshwater. The lowest NOEC of 9.3 mg/L was a result for testing withGammarus pseudolimnaeus(Arthur et al. 1974). An assessment factor of 100 was used as per Part R.10 Guidance for a resulting PNEC for intermittent releases of 0.093 mg/L.

PNEC STP

Swisher et al (1967) provided the only reliable study with STP organisms for which the PNEC could be determined. Results from this test indicated a NOEC of 200 mg/L for exposure of activated sludge organisms to H3NTA. Therefore, the read-across approach was used to apply results from the Swisher et al. study for PNEC calculation for Na3NTA, resulting in a NOEC of 270 mg/L for Na3NTA. As per Part R.10 Guidance, an assessment factor of 1 was used. Although other data with protozoans and Pseudomonas were available, these studies were deemed unreliable or not relevant to PNEC STP. However, they provide support that a PNEC of 200 mg/L would be protective of microorganisms. EU Risk Assessment (2005) presents a PNEC STP of 540 mg/L for a study performed with Chilomonas paramaecium. This protazoan is a flagellate and not a cilliate and therefore, not relevant to STP. Use of flagellate organisms are not listed in the Part R.10 Guidance.

PNEC Intermittent

Reliable short-term data was available for a fish, invertebrate and algae. The lowest LC50 of 80 mg/L was a result for testing with Gammarus pseudolimnaeus (Arthur et al. 1974). An assessment factor of 100 was used as per Part R.10 Guidance for a resulting PNEC for intermittent releases of 0.8 mg/L. The EU Risk Assessment 2005 did not present a PNEC for intermittent releases.