Grapefruit, ext.

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

30/11/2007 - 07/01/2008

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not relevant

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Initial conc.:

>= 31.6 - <= 35.7 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

benzoic acid, sodium salt

Remarks:

Sigma-Aldrich , lot nr 02720

Key result

Parameter:

% degradation (O2 consumption)

Value:

75

Sampling time:

28 d

Details on results:

After 28d a mean degradation value of 75% of the test item was measured. An abiotical degradation of the test item can be excluded as there was no oxygen uptake within the abiotic control. The calculated "toxic effect" of the test item towards microorganisms at the concentration tested can be
neglected as the oxygen uptake within the test solution with the test item was higher than within that of the toxicity control. This special behaviour can be explained by the so-called diauxic effect (in the presence of a second carbon and energy source not always both components are degraded simultaneously as much as within the individual test solutions with the test or control item alone). As there was a degradation >60% of the test item, there is evidence of an inherent biodegradability.

Results with reference substance:

The control item sodium benzoate was degraded 90% within 28d.

Summary of results of testing biodegradability according to OECD 302 C

Time (d)	% Degradation
	TS 1	TS 2	TS 3	TS, Mean value	Tox-control	Sodium Benzoate
0	0.0	0..0	0.0	0	0.0	0.0
0.8	3.8	4.2	3.3	4	15.6	6.3
2.0	7.5	10.7	9.4	9	20.2	36.2
2.9	22.5	25.8	17.9	22	20.9	47.6
3.9	27.9	36.6	24.6	30	26.2	54.4
4.9	30.9	45.2	29.6	35	33.8	58.1
5.9	33.6	49.0	32.7	38	38.0	61.6
6.9	36.4	51.2	35.5	41	40.4	65.9
7.8	38.4	52.4	37.3	43	41.5	69.0
8.8	40.9	54.3	39.8	45	42.5	73.8
9.9	43.8	56.7	42.8	48	44.0	79.7
10.7	45.5	58.3	44.2	49	44.9	82.7
11.8	47.5	60.6	46.1	51	45.8	85.1
12.9	49.5	62.2	48.1	53	47.2	86.9
13.9	51.0	63.9	49.9	55	48.4	88.0
14.8	52.4	65.2	51.9	56	49.6	89.3
16.0	53.5	67.4	55.0	59	51.3	90.2
17.0	54.1	69.9	57.6	61	52.5	90.6
17.9	55.2	72.7	59.9	63	53.6	90.6
19.0	56.4	75.4	61.4	64	55.1	90.8
20.0	57.4	77.7	62.4	66	56.6	90.6
21.0	58.9	79.8	64.0	68	58.4	90.8
22.0	59.8	80.7	64.6	68	59.3	90.8
23.0	60.6	81.7	65.7	69	60.5	90.8
24.0	61.7	83.5	66.8	71	61.3	90.4
25.0	62.8	85.4	68.2	72	61.9	90.4
26.0	63.4	86.7	69.1	73	62.6	90.4
27.0	64.1	88.1	69.8	74	62.8	90.6
28.0	64.6	89.7	71.0	75	63.4	90.2

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

Regarding the results obtained within this study the test item may be considered "inherently biodegradable".

Executive summary:

"Orangenol WMB" was tested for biodegradability according to 'MITI-[II]-Test' (OECD Guideline 302C using a mixture of two natural inocula). The test was performed under GLP. The degradation process was followed by the oxygen uptake in the test solutions. After 28d a mean degradation value of 75% of the test item was measured. An abiotical degradation of the test item can be excluded as there was no oxygen uptake within the abiotoc control. The calculated "toxic effecf' of the test item towards microorganisms at the concentration tested can be neglected as the oxygen uptake within the test solution with the test item was higher than within that of the

toxicity control. This special behaviour can be explained by the so-called diauxic effect (in the presence of a second carbon and energy source not always both components are degraded simultaneously as much as within the individual test solutions with the test or control item alone). As there was a degradation >60% of the test item, there is evidence of an inherent biodegradability. Regarding the results obtained within this study the test item may be considered "inherently biodegradable". The control item sodium benzoate was degraded 90% within 28d. The threshold of ~60% was met within 6d of incubation. Therefore, the test is considered valid.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

other: Known constituent approach

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Grapefruit oil is a Natural Complex Substance (NCS). With 97% of the constituents of Grapefruit oil known, this NCS can be considered as a well defined NCS. Grapefruit oil typically consists for 88% (75-95%) of d-limonene and a range of minor constituents. If the constituents of the NCS are readily biodegradable, the NCS itself is readily biodegradable as well.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

Principles of method if other than guideline:

Assessment of the Ready biodegradability of the known constituents; addition of the percentage of readily biodegrabable constituents in the mixture gives the fraction of ready biodegradable substances. If this fraction exceeds 75%, the NCS is classified as 'readily biodegradable'.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Remarks:

several guideline tests with different inocula were used

Key result

Parameter:

% degradation (O2 consumption)

Value:

> 60

Remarks on result:

other: Decanal, Sabinene, Beta-carophyllene, Citronellal, Nootkatone, Alpha-Pinene , D-limonene, Beta-Myrcene, Linalool, Citral

Key result

Parameter:

% degradation (CO2 evolution)

Value:

> 60

Remarks on result:

other: Alpha-Pinene, Citral, Linalool, Beta-Myrcene, Decanal

Key result

Parameter:

other:

Value:

> 60

Remarks on result:

readily biodegradable based on QSAR/QSPR prediction

Remarks:

Octanal

Details on results:

Details for all constituents are summarised in window "Any other information on results" and in attached document

Assessment of the biodegradability of GRAPEFRUIT OIL:

All of the identified constituents, totaling 97% of the composition, is readily biodegradable, see underlying data in table below. One constituen (1% of the composition) was readily biodegradable but failed the 10-d window criterion.

Constituent	Chemical Structure	Typical %	Results of biodegradation assessment
D-limonene C10H16		88 %	READILY BIODEGRADABLE: - Headspace CO2: 71.4% (Quest 1993). The biodegradability of perfume ingredients in the sealed vessel test. - MITI (I) / OECD 301C, improved for volatile substance: Limonene 14d - BOD: 41, 81, 98% Direct analysis: GC: 100%; TOC 50, 73, 81% (MITI 1980 http://www.safe.nite.go.jp/sitemap/db_map_e.html) - Readily biodegradable (Misra, G.; Pavlostathis, S. G.; Perdue, E. M.; Araujo, R. Applied Microbiology and Biotechnology (1996), 45(6), 831-838.)
a-Pinene C10H16		0,5 %	READILY BIODEGRADABLE: - OECD301B, sealed vessels: 62% (28d), 70% (42d) (Astra Zeneca, 2001, ECB PBT#84 http://ecb.jrc.ec.europa.eu/documents/PBT_EVALUATION/PBT_sum084_CAS_91770-80-8.pdf).                                                 - MITI (I) / OECD 301C: 28d - BOD: 91, 90, 95% Direct analysis: GC: 100, 100, 100% (MITI 2007: http://www.safe.nite.go.jp/sitemap/db_map_e.html)
Citral C10H16O		0,5 %	READILY BIODEGRADABLE: - Modified 301B, sealed vessels CO2: 92.1% in 28 d (Quest 1994) - MITI (I) / OECD 301C, improved for volatile substance (Citral is mixture of neral and geranial): 28d - BOD: 92% Direct analysis: TOC: 78%; GC: 100% The test substance formed 6-Methyl-5-hepten-2-one (2-2480) and Geranic acid in (Water + Test Substance) system. (MITI 1991: http://www.safe.nite.go.jp/sitemap/db_map_e.html)
b-Myrcene C10H16O		2 %	READILY BIODEGRADABLE: - OECD 310 Carbon Dioxide Headspace test: CO2 production: 73% (Van Ginkel 2009) - MITI (I) / OECD 301C, improved for volatile substance: 14d - BOD: 86% Direct analysis: GC: 99%; TOC: 97% (MITI 1987: http://www.safe.nite.go.jp/sitemap/db_map_e.html)
Sabinene C10H16		0,5 %	READILY BIODEGRADABLE: - OECD 301F: 76% in 28d (Givaudan 2010) Sabinene (72% pure with 27% beta-pinene)
b-carophyllene C15H24		1 %	READILY BIODEGRADABLE: - OECD301F - 75% (REF: Givaudan, 2007)
Citronellal C10H18O		0,5 %	READILY BIODEGRADABLE: - OECD 301F: 61% (28d), 51% in 10d-window (Givaudan 1994) Supported by prediction from EPISuite/ BIOWIN v4.10 (March 2009): readily biodegradable - yes
Decanal C10H20O		1,5 %	READILY BIODEGRADABLE: - OECD 301D Closed Bottle test: BOD 66% (14d) AND - OECD 310 Carbon Dioxide Headspace test: CO2 production 72% (14d), > 80% (28d) (RIFM/Givaudan/Akzo Nobel: A. Lapczynski, D. Salvito, K. Jenner, R. Geerts, C. Van Ginkel: Ready biodegradability testing of volatile poorly water soluble fragrances; Possible pitfalls. Poster SETAC North America 29th Ann. Meeting Tampa, Fl, November 2008, http://rifm.org/doc/RIFM%20SETAC%20Tampa%20Poster%20112008.pdf)
Linalool C10H18O		0,5 %	READILY BIODEGRADABLE: - OECD 301C: 80% (Givaudan 1991) - OECD Modified 301B, sealed CO2: 97.1% (QUEST 1994)                               - Readily biodegradable (Misra, G.; Pavlostathis, S. G.; Perdue, E. M.; Araujo, R. Applied Microbiology and Biotechnology (1996), 45(6), 831-838.)  - MITI (I) / OECD 301C: 28d - BOD: 90% Direct analysis: TOC 99% GC: 100%; (MITI 1996 http://www.safe.nite.go.jp/sitemap/db_map_e.html)
Nootkatone C15H22O		1 %	READILY BIODEGRADABLE but failing the 10-d window Inherently and ultimately biodegradable - OECD 301F: 65% in 28 days but failing the 10-d window (Givaudan 2010)
Octanal C8H16O		1 %	READILY BIODEGRADABLE: Read across from decanal   supported by prediction from EPISuite/ BIOWIN v4.10 (March 2009): readily biodegradable - yes
		97%	Fraction of NCS readily biodegradable

 

The complete asssessment is added attached to this study record. Studies mentioned by Company Name are included in the RIFM database.

Validity criteria fulfilled:

not applicable

Interpretation of results:

readily biodegradable

Conclusions:

Grapefruit oil is considered as readily biodegradable.

Executive summary:

Grapefruit oil is a Natural Complex Substance (NCS) for which 97% of the constituents is identified. Grapefruit oil typically consists for 88 % of d-limonene (range 75 -95%) and a range of minor constituents. As no valid empirical results from a test for the ready biodegradation of Grapefruit oil are available, the assessment is based on its constituents. The assumption is that if the constituents of the NCS are readily biodegradable, the NCS itself is readily biodegradable as well.

For 96% of the constituents the available data are obtained in tests on the ready biodegradability. For 1 constituent (1%) the results are based on read across and for 1 constituent no data are available.

Grapefruit oil is considered as readily biodegradable.

 

Description of key information

97% of the composition of this NCS is in the category of readily biodegradable substances. Therefore, Grapefruit oil is considered readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Grapefruit oil is a Natural Complex Substance (NCS) for which 97% of the constituents is identified. The constituents are predominantly alicyclic unsaturated monoterpene hydrocarbons, including d-limonene, typically 88 % (range 75 -95%) and a range of minor constituents. The assessment of the biodegradability of Grapefruit oil is based on its constituents. The assumption is that if the constituents of the NCS are readily biodegradable, the NCS itself is readily biodegradable as well.

All of the known constituents, comprising typically 97% of the composition of this NCS, are in the category of readily biodegradable substances. One constituent (1%) is readily biodegradable but not meeting lacking the 10 -d window criterion.

Grapefruit oil is considered readily biodegradable.