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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Toxicity to soil macroorganisms except arthropods

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Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: short-term
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH
See read-across justification report under Section 13 ‘Assessment Reports’.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In accordance with REACH Annex XI, Section 1.5, of Regulation (EC) No. 1907/2006 (REACH) the standard testing regime may be adapted in cases where a grouping or read-across approach has been applied.

The similarities may be based on:
(1) a common functional group
(2) the common precursors and/or the likelihood of common breakdown products via physical or biological processes, which result in structurally similar chemicals; or
(3) a constant pattern in the changing of the potency of the properties across the category

1. Both substances are inorganic salts of a monovalent cation from Group 1A of the periodic table, sodium or potassium, and phosphoric acid. Thus, they all share the Na+ or K+ cation and the PO43- anion as common functional groups. 2. All members of the group will ultimately dissociate into the common breakdown products of the Na+ or K+ cations and the PO43- anion. 3. Sodium and potassium orthophosphates have been shown to have a similar toxicological profile and physicochemical nature and therefore this data is considered to be adequate and reliable for use in read-across. Any further testing would not be scientifically justified as all substances will dissociate to their anionic and cationic forms in natural waters and these ions (Na+, K+ and PO43-) are all ubiquitous and are not considered to pose a risk of ecotoxicity

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across justification report under Section 13 ‘Assessment Reports’.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across justification report under Section 13 ‘Assessment Reports’.

4. DATA MATRIX
See read-across justification report under Section 13 ‘Assessment Reports’.
Cross-reference
Reason / purpose for cross-reference:
read-across: supporting information

Data source

Reference
Reference Type:
publication
Title:
A comparison of the relative toxicity of bone meal and other P sources used as remedial treatments to the earthworm
Author:
Atuah L & Hodson ME
Year:
2011
Bibliographic source:
Pedobiologica - International Journal of Soil Biology

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 207 (Earthworm, Acute Toxicity Tests)
GLP compliance:
no
Remarks:
Study was not performed for the purpose of REACH registration.

Test material

Constituent 1
Chemical structure
Reference substance name:
Potassium dihydrogenorthophosphate
EC Number:
231-913-4
EC Name:
Potassium dihydrogenorthophosphate
Cas Number:
7778-77-0
Molecular formula:
H3O4P.2K
IUPAC Name:
potassium dihydrogen phosphate
Details on test material:
- Name of test material (as cited in study report): potassium hydrogen phosphate (KH2PO4)

Test substrate

Vehicle:
no
Details on preparation and application of test substrate:

- Controls: unamended soil

Test organisms

Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
TEST ORGANISM
- Common name: earthworm
- Source: Blades biological Ltd, Cowden, Edenbridge, Kent, UK
- Age at test initiation (mean and range, SD): no data
- Weight at test initiation (mean and range, SD): 340 +/- 3.7 mg

ACCLIMATION
- Acclimation period: no data

Study design

Study type:
laboratory study
Substrate type:
natural soil
Limit test:
no
Total exposure duration:
28 d

Test conditions

Test temperature:
20°C
pH:
7-7.2
Moisture:
60% water holding capacity
Details on test conditions:
TEST SYSTEM
- Test container (material, size): no data
- Amount of soil or substrate: 500 g
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: Jetting Loam - bought
- Soil texture (if natural soil): sieved to less than 2mm

Properties are similar to the OECD standard soil.

OTHER TEST CONDITIONS
- Photoperiod: performed in dark


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
Nominal and measured concentrations:
15,000 mg P/kg with concentrations decreasing by a factor of 1.8 downwards to 441 mg P/kg
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
14 d
Dose descriptor:
LC50
Effect conc.:
> 3 500 other: mg P/ kg
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Duration:
28 d
Dose descriptor:
LC50
Effect conc.:
> 3 500 other: mg P / kg
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
LC50 (14 day and 28 day values) of potassium dihydrogen phosphate was found to be > 3500 mg P / kg.