C4-C10 branched and linear hydrocarbons (light) – Naphtha

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This endpoint has been reviewed, assessed and accepted by UK-HSE as competent authority for the notification of a new substance [EC number: 481-730-0; Data from UK-Notification Dossier by Shell U.K. Limited in accordance with Directive 92/32/EEC (Articles 7/8/9/12) O.J.L 154, Volume 35, 5 June 1992; Notification Report 06-31-0125-00 from 1st Nov, 2006].

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

other: review

Title:

Unnamed

Year:

2006

Materials and methods

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

The toxicity of the representative chemical components of the substance to invertebrates (Daphnia) have been calculated in accordance with the methods described by Peter Fisk Associates (2006) using QSARs for non-polar narcotics. The QSARs take the form of a generic equation:
log(LC50, EC50 or NOEC) = a log(Kow) + b
where a and b are constants equal to the slope and the intercept on the y axis of the regression equation and Kow is octanol-water partition coefficient of each component under consideration.

GLP compliance:

no

Remarks:

not applicable (calculated by QSAR )

Test material

Reference

Name:

Unnamed

Type:

Constituent

Sampling and analysis

Analytical monitoring:

not required

Test organisms

Test organisms (species):

other: not applicable (calculated by QSAR)

Study design

Test type:

other: not applicable (calculated by QSAR)

Water media type:

not specified

Remarks on exposure duration:

NOT_SPECIFIED

Results and discussion

Effect concentrations

Effect concentrations 1

Dose descriptor:

EL50

Effect conc.:

4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: not applicable (calculated by QSAR )

Effect concentrations 2

Dose descriptor:

NOELR

Effect conc.:

0.12 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: not applicable (calculated by QSAR)

Any other information on results incl. tables

see attached full study report at "5.2.1 Biodegradation in water: screening tests" [ Attachment 8, page 5 -12]

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Remarks:

calculated by QSAR

Conclusions:

Results calculated by QSAR [using the methods described in the report by Peter Fisk Associates (2006)]:
- the substance could be acutely toxic to invertebrates at a loading rate of 4.0 mg/l (EL50)
- the substance has a predicted chronic NOEL of 0.12 mg/l to invertebrates.

Measurements in acute tests with related substances, which were reported in the environmental hazard property summary review by Peter Fisk Associates (2006) [see below 'Cross-reference to other study' or Attachment 8] give lowest LL50 or EL50 values that are in the range 1-10 mg/l, although there is one exceptional measured value indicating a lower order of toxicity (see below 'Cross-reference to other study': first CONCAWE-study). It should be noted that the original study reports have not been reviewed.

Conclusion: Naphtha (Fischer-Tropsch), light, C4-10 - branched and linear, could be chronically toxic to invertebrates at a loading rate of 0.1-1.0
mg/l and could be acutely toxic at a loading rate of 1-10 mg/l.

Classification: The substance should be classified in the EU as R50-53 i.e. 'Very toxic to aquatic organisms' and 'May cause long-term adverse effects in the aquatic environment'. The basis of this classification is the lowest predicted EL50 of 0,55 mg/l to algae and the presence of components with log Kow >3. The biodegradability does not affect this.