Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted according to OECD Guidelines, with no or minor deviations.
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Deviations:
yes
Remarks:
Extended beyond the standard 28 days.
Qualifier:
according to
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
Qualifier:
according to
Guideline:
EPA OPPTS 835.3110 (Ready Biodegradability)
GLP compliance:
yes (incl. certificate)
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Duration of test (contact time):
70 d
Initial conc.:
30 mg/L
Based on:
test mat.
Parameter:
% degradation (O2 consumption)
Value:
0
Sampling time:
28 d
Parameter:
% degradation (O2 consumption)
Value:
61
Sampling time:
70 d
Details on results:
As < 60% biodegradation was observed after 28days, the ready biodegradability test was prolonged in order to assess the inherent biodegradability of the substance. Biodegradation began around day 30 and gradually increased to a level of 61% after 70 days. From the timeplot the > 60% biodegradation was achieved from day 66 onwards.

Oxygen uptakes, as read on the Oxitop controller, are corrected to account for the small differences between actual and nominal concentrations of test and reference substances.
Oxygen uptake curves can be found in Appendix 1 of the attached study report. Calculated % biodegradation curves and detailed results are reported in Appendixes 2 to 4 of the attached study report.
Degradation of sodium benzoate exceeded 40% after 7 days and 65% after 14 days: the activity of the inoculum was thus verified (validity criterion).
The repeatability validity criterion (not more than 20% difference between replicates) is fulfilled on day 28 of the test, key date for the interpretation of the results. Therefore, the test is considered valid.
Validity criteria fulfilled:
yes
Interpretation of results:
other: Not readily biodegradable but Inherently and ultimately biodegradable
Conclusions:
The biodegradability of SAFRANAL P was determined by the Manometric Respiratory Test according to OECD Guidelines No 301F. Under the conditions of the test, no biodegradation was observed after the standard 28 day test period. Thus, SAFRANAL P should be regarded as not readily biodegradable according to this test.

As less than 60% biodegradation was observed after 28 days, the ready biodegradability test was prolonged in order to assess the inherent biodegradability of the substance. Biodegradation began around day 30 and gradually increased to a level of > 60% 61% after 70 days. From the timeplot the > 60% pass criterion was achieved from day 66 onwards. Based on these results SAFRANAL P should be regarded as inherently and ultimately biodegradable.

SAFRANAL P did not significantly inhibit the intrinsic respiration of the inoculum at the test concentration and was therefore considered to be non-toxic to the inoculum at the test concentration of 30mg/L.

Description of key information

Safranal is not readily biodegradable based on the strict criteria for this effect. However, it is considered to be inherently and ultimately biodegradable, and not persistent based on > 60% biodegradation in a prolonged OECD 301F ready test.

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable
Type of water:
freshwater

Additional information

The registered substance 2,6,6-trimethylcyclohexa-1,3-dienecarbaldehyde is a mono-constituent substance (EC 204-133-7, CAS 116-26-7). Two commercial qualities are covered by the REACH registration,

Safranal and Safranal P. The only difference between the two qualities is the amount of the additive, alpha-tocopherol (EC 233-466-0, CAS 10191-41-0), that is intentionally added to stabilise the

substance. The level of this additive is 9-14% in Safranal and 1-2% in Safranal P. The latter was used in the biodegradation study because of the lower alpha-tocopherol level and hence higher purity of mono-constituent substance.

The biodegradability of SAFRANAL P was determined by the Manometric Respiratory Test according to OECD Guidelines No 301F. Under the conditions of the test, no biodegradation was observed after the standard 28 day test period. Thus, SAFRANAL P should be regarded as not readily biodegradable according to this test.

As less than 60% biodegradation was observed after 28 days, the ready biodegradability test was prolonged in order to assess the inherent biodegradability of the substance. Biodegradation began around day 30 and gradually increased to a level of 61% after 70 days. Based on these results SAFRANAL P should be regarded as inherently and ultimately biodegradable.

SAFRANAL P did not significantly inhibit the intrinsic respiration of the inoculum at the test concentration and was therefore considered to be non-toxic to the inoculum at the test concentration of 30mg/L.