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

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

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].

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

Deviations:

not applicable

Principles of method if other than guideline:

For the estimation/calculation the percentages by weight and the mean percentages of branching (given in Attachment 8, Table 1) have been used to determine a composition of a typical sample of the substance 'Naphtha (Fischer-Tropsch), light, C4-C10 - branched and linear'. This composition has been used as the basis for modelling biodegradability.

GLP compliance:

no

Remarks:

not applicable (estimated by calculation)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Study design

Oxygen conditions:

other: not applicable (estimated by calculation)

Inoculum or test system:

other: not applicable (estimated by calculation)

Duration of test (contact time):

ca. 28 d

Results and discussion

% Degradation

Parameter:

other: calculation

Value:

> 60

Sampling time:

28 d

Remarks on result:

other: 67.5% of test substance is predicted to be readily biodegradable and passing the 10-day window ; 22.5% of test substance is predicted to be readily biodegradable but not passing the 10-day window

Details on results:

The biodegradability of the chemical components of the substance has been predicted in accordance with the methods described by Peter Fisk Associates (2006). The results of applying these methods to a typical composition (see Attachment 8, Section 3 and Table 1 and 2) show that 67.5% of the mass of the substance would be considered readily biodegradable, passing the 10-day window (RB10), 22.5% would be readily biodegradable not passing the 10-day window (RBN) and 10% would be inherently biodegradable (INH).

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Remarks:

estimated by calculation

Interpretation of results:

readily biodegradable

Conclusions:

A reasonable conclusion that can be drawn is that, Naphtha (Fischer-Tropsch), light, C4-10 - branched and linear, should be considered to be readily biodegradable. The substance would therefore be classed 'readily biodegradable'.
Test data found in the literature for 'Naphtha (petroleum), hydrotreated light' (CAS No. 64742-49-0), which was reported in the environmental hazard property summary review by Peter Fisk Associates (2006), support this conclusion (see Attachment 8 or below "Cross-reference to other study"). It should be noted that the original study reports have not been reviewed.