Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Non-quantitative study of effect of increasing concentration of test substance on the sewage treatment process
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
no
Test organisms (species):
activated sludge
Test type:
not specified
Water media type:
not specified
Limit test:
no
Total exposure duration:
30 d
Duration:
30 d
Dose descriptor:
NOEC
Effect conc.:
200 mg/L
Nominal / measured:
nominal
Conc. based on:
not specified
Basis for effect:
other: sewage gas production volume
Duration:
30 d
Dose descriptor:
LOEC
Effect conc.:
500 mg/L
Nominal / measured:
nominal
Conc. based on:
not specified
Basis for effect:
other: sewage gas volume reduced and fermentation delayed
Details on results:
At 50 mg/L the test material showed no effects.
At 100 and 200 mg/L the start of fermentation was delayed, but constant gas volume was achieved in the same period as in the control.
At 500 mg/L the test material , the system was strongly disturbed, as indicated by a late beginning of fermentation, and greatly reduced sewage gas production volume.
Conclusions:
A non-standard study of effects on sewage treatment plant micro-organisms was conducted according to generally accepted scientific principles but lacks detail in the study report. The result of a lack of effects on respiration up to 200 mg/L provides reliable evidence.
Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Results determined in Sapromat test, derived from comparison of biochemical oxygen demand
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
no
Test organisms (species):
activated sludge
Details on inoculum:
Klaeranlage-Muenchen-Grosslappen
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
5 d
Remarks on exposure duration:
Whilst the exposure duration is not explicitly stated, BOD5 values are quoted and so it is deduced that the exposure period is at least 5 days duration.
Post exposure observation period:
Not reported
Hardness:
Not reported
Test temperature:
Not reported
pH:
Not reported
Dissolved oxygen:
Not reported
Salinity:
Not reported
Nominal and measured concentrations:
Not reported
Details on test conditions:
Test concentration series: 1, 5, 10, 50 and 100 mg/L
Reference substance (positive control):
no
Duration:
5 d
Dose descriptor:
EC0
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Validity criteria fulfilled:
not applicable
Conclusions:
A non-standard study of activated sludge respiration inhibition determined that the top concentration of 100 mg/L did not cause inhibition. The result is considered reliable.

Description of key information

EC0 200 mg/l activated sludge respiration inhibition (non-standard test, rel. 2) Henkel 1972. The data are read across from the parent acid ATMP.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:
200 mg/L

Additional information

A number of non-standard studies are available providing evidence that ATMP has no inhibitory effect on micro-organisms at concentrations up to ca. 200 mg/L.

A study of seven Swiss WWTPs in 1996 shows a maximum concentration of ATMP in WWTP untreated influent of ca. 0.8 µmol/L, equivalent to ca. 0.26 mg/L.

The data set is further supported by the findings of an activated sludge respiration inhibition test conducted with an ammonium salt of ATMP (Worth and Mead, 1995). In this reliable study conducted in accordance with OECD Test Guideline 209, an EC50 >1000 mg/l was determined based on a 3-hour exposure period.

 

ATMP-H (CAS 6419-19-8) has three methylphosphonate groups connected by a central tertiary amine nitrogen. ATMP-N-oxide-H (15834-10-3) has a directly analogous chemical structure with a central tertiary amine N-oxide group.

As well as being structural analogues, both phosphonates have consistent chemical properties including moderate MW (299 and 315 respectively), very low log Kow(-3.53 and ≤-4respectively) and are highly soluble in water. The substances generally possess similar physico-chemical properties and are expected not to be readily biodegradable in the environment.Information about tertiary amine N-oxides suggests that read across of effects data from the amine to the N-oxide is valid and precautionary.

 

Both acid and certain salt forms of these phosphonates behave no differently from each other and are fully dissociated in dilute aqueous conditions of defined pH, when presented at identical concentrations. In environmental fate and ecotoxicity studies, the local pH and ionic conditions within the environment dominate the speciation of the phosphonate, irrespective of the form originally added. At a defined pH, a salt will behave no differently to the parent acid, at identical concentration of the speciated form present, and will be fully dissociated to yield acid and counter-ion.

The read-across justification is attached in IUCLID Section 13.