[No public or meaningful name is available]

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

See Attached Justification

Qualifier:

no guideline required

Principles of method if other than guideline:

- Software tool(s) used including version:
See Field 'Attached justification'
- Model(s) used:
See Field 'Attached justification'
- Model description: See Field 'Attached justification'
- Justification of QSAR prediction: see field 'Attached justification'

GLP compliance:

not specified

Specific details on test material used for the study:

Cumulative concentrations (%) per chemical class and carbon number

Class Carbon No. Concentration (%)
MoAr C6 15.00
MoAr C7 5.23
MoAr C8 0.11
n-Olefins C5 16.55
n-Olefins C6 3.69
n-Olefins C7 0.80
n-Olefins C9 0.48
n-Olefins C10 45.93
n-Olefins C11 16.99

Total 104.77

The constituents that could fit in more than one HC block, or that did not fit in any specific block, were placed in a relavant block that presented the highest toxicity.

Test organisms (species):

Lumbriculus variegatus

Duration:

28 d

Dose descriptor:

other: EL10

Effect conc.:

39.7 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results based on QSAR predicted value

Validity criteria fulfilled:

yes

Conclusions:

The QSAR predicted EL10 for Distillates (Petroleum), steam-cracked, dimerised (C5-12, C10-rich) was 39.7 mg/kg sediment dw.

Executive summary:

The QSAR predicted EL10 for Distillates (Petroleum), steam-cracked, dimerised (C5-12, C10-rich) for Lumbriculus variegatus was 39.7 mg/kg sediment dw. The model used for the calculations was the PETROTOX v4.0 model. PETROTOX is a well-documented and peer reviewed model that is widely used across the chemicals industry. This substance fits within the criteria of the model and there are no reservations about the validity of the model runs. It is expected that this data is reliable with restrictions.

Description of key information

The sediment toxicity was predicted by a QSAR, the PETROTOX v4.0 computer model. PETROTOX is a well-documented and peer reviewed model that is widely used across the chemicals industry. The substances of this category fit within the criteria of the model and there are no reservations about the validity of the model runs. The predicted LL50 values for Lumbriculus variegatus was 207 mg/kg sediment dw. The predicted EL10 values for Lumbriculus variegatus was 39.7 mg/kg sediment dw.

Key value for chemical safety assessment

EC50 or LC50 for freshwater sediment:

207 mg/kg sediment dw

EC10, LC10 or NOEC for freshwater sediment:

39.7 mg/kg sediment dw

Additional information

Due to the lack of experimental data, the sediment toxicity was calculated by a QSAR, the PETROTOX v4.0 computer model.

 

The PETROTOX v4.0 model for sediment and terrestrial organism calculates the constituent concentration in sediment or soil using the product composition (% mass) along with the total sediment/soil (s/s) loading rate (concentration of the full substance as added to the soil/sediment). The model then uses the equilibrium-partitioning calculations to convert aqueous-based effect concentrations (EC50, mmol/L) to soil or sediment based values (mmol/kg oc) for each constituent using the CTLBB for the soil or sediment organism. Then, it combines the s/s based concentration (mg/kg dw) and the effect concentrations in soil or sediment based values (mmol/kg oc) to compute toxic units for each constituent, which are then summed to determine the overall effect concentration (LC50ss) of the substance.

 

The predicted values were:

Species	Substance CAS No.	LL50/EL50 (mg/kg sediment dw)	EL10 (mg/kg sediment dw)
Lumbriculus variegatus	68477-53-2	207	39.7