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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

SUMMARY OF THE MOST RELEVANT AQUATIC ECOTOXICITY DATA FOR THE REGISTRATION SUBSTANCE

For all relevant trophic levels - fish, daphnia and algae as well as microorganisms - acute ecotoxicity values are available with Daphnia as the most sensitive species. Fish is the least sensitive species and therefore and for animal welfare reasons no chronic fish tests were carried out. Chronic tests are available for daphnia (21d Reproduction test) and algae (EC10 growth rate). In the table below the most relevant ecotoxicity data for the registration substance and read-across substances are given:

Primary alkyl amines & Salts
      C16-18 C16-18, 18u C18 C16-18 (sat.&unsat.) C12-18, 18u
               
Fish OECD 203 LC50 (96h) mg/L 0.88 0.25 - 4.21 (RW) 0.84 (RW)
Daphnia OECD 202 EC50 (48h) mg/L 0.04 0.23 0.13 0.98 (RW) 0.32 (RW)
Algae OECD 201 ErC50 (72h) mg/L 0.12 0.39 (RW)   0.46 (RW) 0.16 (RW)
    Bacteria OECD 209 EC10 (3h) mg/L  -  7  -  -  5.5
   Bacteria OECD 209 EC20 (3h) mg/L 214 - - 62.5 -
    Bacteria OECD 209 EC50 (3h) mg/L 490  32   222 14 
Daphnia OECD 211 NOEC repro (21d) mg/L - 0.013 (RW) - 0.013 (RW) 0.013 (RW)
Algae OECD 201 ErC10 (72h) mg/L 0.029 0.13 (RW) - 0.15 (RW) 0.06 (RW)
RW=River water test

Daphnia has the lowest chronic NOEC and this value from a river water test is selected for the derivation of the PNEC freshwater according the Bulk approach (see Category Approach for Primary alkyl amines under REACH and Existing Substances Regulation 93/793/EEC).

Additional information

Category Approach for Primary alkyl amines and their salts e.g. Acetates

Primary alkyl amines and acetate salts are characterized by the hydrophobic aliphatic alkyl chain as well as a hydrophilic amine/ammonium group. They are mostly protonated under physiological or environmental conditions (pH 4-9). The degree of protonation is exclusively determined by the pKa and the pH and therefore it is irrelevant if the amine itself or its salt is considered.

 

Considering these characteristics and that primary alkyl amines and primary alkyl amines acetates have a close structural relationship and share common functionalities as well as metabolic pathways, they can be considered as chemically and biologically equivalent. It is therefore imperative to use read-across principles in the assessment of primary alkyl amines and acetate salts. The read-across data from non neutralized amine compounds is used without molecular weight correction, where it is assumed that the acetate counterion does not contribute to the toxicity. Therefore the 1:1 read-across-approach can be seen as worst-case approach from a scientifically point of view.

 

Primary alkyl amines were already assessed for their environmental and human health hazards and risks under the EU Existing Chemicals Regulation 793/93/EEC. Industry has provided a justification for the category approach to the German rapporteur BAuA on 2001-04-07. This justification was accepted as basis for the EU Risk assessment and is used for the REACH registration as well.

Speciation of Primary alkyl amines

In aqueous medium the unprotonated and the protonated amine are in equilibrium. The percentage of the unprotonated and the protonated amine is determined by the acid constant pKa and the given pH. In the table the percentages are given as function of pH and the pKa of 10.5 for Primary alkyl amines.

pH  Percentage Protonated amine (N+)  Percentage Unprotonated amine (N) 
97.5%  2.5% 
99.975%  0.025% 
 99.99997% 0.000003% 

CONCLUSION:

Under environmental conditions it is not relevant if the unprotonated or the protonated amine will be introduced in an aquatic medium. The composition of the protonated and unprotonated amine is solely determined by the pKa and the ambient pH (see table above). Therefore aquatic test results from the unprotonated and protonated amine are equivalent.

River water tests, Mitigation factor, PECbulk, PNECbulk

For the primary fatty amines and acetates under consideration short-term studies are available for fish, aquatic invertebrates and algae. Long-term data are available for aquatic invertebrates and algae.

The standard tests submitted were conducted using synthetic growth media. These tests do not take into account particulate matter and dissolved organic carbon (DOC). Since primary fatty amines and acetates are positively charged under environmental conditions, they might adsorb on surfaces such as test vessels or organic material (e.g. test organisms such as algae). The results of ecotoxicity testing might be influenced by these secondary effects. In order to reduce the influence of secondary effects modifications such as river water tests or tests in the presence of humic acids) are introduced as more realistic conditions and used as higher tier studies.

For the aquatic risk assessment of strongly sorbing substances the current REACH Guidance Documents do not provide sufficient guidance concerning both effects and exposure assessment. An alternative for strongly sorbing substances can be the PEC/PNECaquatic bulk approach (ECETOC 2003). This approach is based on a PNECaquatic bulk which is derived from a modified ecotoxicity test using humic acid, natural water or effluent and a PEClocal, aquatic bulk which represents the total aquatic concentration (dissolved and sorbed = bulk). The risk quotient for the aquatic compartment is calculated by using nominal concentrations.

Testing primary fatty amines under more realistic conditions in the presence of humic acids or in river water indicate that bioavailability is lower compared to studies using standard media. Following the reasoning above, tests conducted under environmentally realistic conditions (i.e. in river water) will be used for effects assessment of primary fatty amines.

The ecotoxicity is mitigated due to sorption but this kind of tests at least ensures that all added test substance is present in the test system and available for the exposure of the organism in dissolved or sorbed form. Mitigation can be taken into account by a factor of 10 applied to the ecotoxicity result (L(E)C50) for C&L. For risk assessment purposes these ecotoxicity results can be compared with the total or bulk concentration in surface water.

Additional Literature

ECETOC (2003): Environmental Risk Assessment of Difficult Substances. Technical Report No. 88