Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.4 mg/L
Assessment factor:
100
Extrapolation method:
assessment factor

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.04 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
20 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
603 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
60.3 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
240 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

There are only short-term data available with the registered substance, however data are available with the structurally analogous substance ATMP acid (EC 229-146-5, CAS 6419-19-8). ATMP-N-oxide-5K (EC 700-903-6, CAS 255830-15-0) will fully dissociate in aqueous solution and will behave no differently to the parent ATMP acid or ATMP-N-oxide acid and its sodium or potassium counter ion at equivalent concentrations. The N-oxide properties and the counterions are thought not to affect the ecotoxicological properties of ATMP (refer to RAAF documents in IUCLID Section 13). Therefore, the impact on aquatic organisms will be dominated by the effects of ATMP acid and the PNECs are presented in terms of acid.

 

ATMP and its salts are phosphonic acid substances of very high water solubility, and low octanol-water partition coefficient. The phosphonic acid groups are multiply ionised at pH values relevant to biological and environmental systems. Ionisation gives them the ability to form stable complexes with metal ions, particularly polyvalent ones. Phosphonates are found to adsorb strongly to inorganic matrices, and hence they adsorb strongly to sewage sludge and to soil. They will be removed to a high extent in biological waste water treatment by adsorption.

 

The toxicity of ATMP-N-oxide and its salts to environmental species is presented and interpreted in terms of the concentration of active ATMP-N-oxide acid in the test media. As such the results of tests conducted on ATMP-N-oxide and its salts are directly comparable, because the ionisation state will depend only on the pH of the test medium. In aqueous solution, ATMP-N-oxide-5K will ionise to form ATMP-N-oxide acid and potassium ions. Six dissociation constants were obtained for the potassium salt of ATMP-N-Oxide: pKa1 = <2, pKa2 = <2, pKa3 = 3.28, pKa4 = 5.27, pKa5 = 6.99 and pKa6 = 12.09. At environmentally-relevant pH values ATMP-N-oxide acid will be ionised typically four or five times, and will form stable complexes with metal ions (Spini 2000, in IUCLID section 4.21).

 

The substances have the potential to cause effects on aquatic plants as a consequence of nutrient deficiency and reduced uptake caused by complexation of trace metals. As complexing agents, these substances could remobilise metals in the environment; however, their high degree of adsorption to sediments suggests that this is unlikely to occur. The substances are acids and when present at high concentration they have the potential to cause local effects on aquatic organisms because of lowered pH.

 

Effects on aquatic organisms arising from exposure to the acid form of the substance are thought to result from a reduction in the pH of the ambient environment (arising from an increase in the H+concentration) to a level below their tolerable range. It is not considered appropriate or useful to derive a PNEC with studies in which pH deviations may have been attributable to the cause of effects seen because any effects will not be a consequence of true chemical toxicity and will be a function of, and dependent on, the buffering capacity of the environment. Physical hazards related to pH effects are considered in the risk management measures (e.g. neutralisation) for effluents/aqueous waste.

 

Further details on the analogue read-across between ATMP and ATMP-N-oxide categories are attached in Section 13 of the IUCLID dossier.

Conclusion on classification

The substance has not been classified for the environment according to Regulation (EC) No 1272/2008 based on long term NOEC values being >1 mg/L for the structurally analogous substance used for read-across.