Fatty acids, C16 and C18-20 (even numbered, unsaturated), 2-ethylhexyl esters

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

It is considered appropriate to address the ready biodegradability data requirement for fatty acids, C12-20 and C12-20 unsatd., 2-ethylhexyl esters by applying read-across from available data on fatty acids, tall-oil, epoxidized, 2-ethylhexylesters (ETP) (a UVCB substance), given that both substances are of similar chemical structure, being long- chain esters with 2-ethyl hexanol. A read-across justification document is attached in section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Parameter:

other: COD

Value:

70

Sampling time:

28 d

Table 1. Oxygen consumption in test flasks:

Time (days)	Cumulative oxygen consumption (mg/L)
	Test item		Inoculum control		Procedure control		Abiotic control	Toxicity control
	Flask No.		Flask No.		Flask No.		Flask No.	Flask No.
	1	2	5	6	3	4	7	8
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28	0 3 28 48 - - 91 102 112 121 130 - - 155 162 171 178 186 - - 208 217 227 233 237 242 - 248 252	0 5 27 45 - - 79 87 95 102 111 - - 135 142 152 160 171 - - 193 201 210 216 222 230 - 240 245	0 0 3 5 - - 8 9 9 10 10 - - 11 11 11 12 12 - - 12 12 12 12 12 12 - 12 13	0 0 3 5 - - 8 9 10 10 11 - - 12 12 12 12 12 - - 12 13 13 13 13 13 - 13 13	0 21 79 101 - - 138 142 145 146 148 - - 151 152 153 154 155 - - 156 157 157 158 158 159 - 161 162	0 21 76 96 - - 134 139 142 145 147 - - 151 153 154 155 156 - - 157 157 158 158 158 158 - 158 159	0 0 0 0 - - 0 0 0 0 0 - - 0 0 0 0 0 - - 0 0 0 0 0 0 - 0 0	0 31 76 100 - - 180 194 207 217 227 - - 252 259 269 276 285 - - 307 314 324 329 336 346 - 354 359

- No reading taken

Table 2: Biodegradation in the test flasks

Time (days)	Percentage biodegradation^1
	Test item		Procedure control		Toxicity control
	Flask No.		Flask No.		Flask No.
	1	2	3	4	8
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28	0 1 7 13 - - 25 28 31 33 36 - - 43 45 48 50 52 - - 59 61 64 66 67 69 - 70 72	0 1 7 12 - - 21 23 25 27 30 - - 37 39 42 44 47 - - 54 56 59 60 62 65 - 68 69	0 13 46 57 - - 78 80 81 81 82 - - 84 84 85 85 86 - - 86 87 87 87 87 88 - 89 89	0 13 44 54 - - 75 78 79 81 82 - - 84 85 85 86 86 - - 86 87 87 87 87 87 - 87 87	0 6 14 19 - - 34 37 39 41 43 - - 48 49 51 52 54 - - 58 60 62 63 64 66 - 68 69
Mean (day 28)	70		88

¹Corrected for the mean oxygen uptake of the inoculums controls

- Not determined

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item fatty acids, tall-oil, epoxidized, 2-ethylhexylesters (ETP) was investigated for their ready biodegradability in a manometric respirometry test over 28 days according to EU Commission Directive 92/69 EEC, C.4-D (1992) and OECD Guideline for Testing of Chemicals No. 301 F (1992).

The percent biodegradation of the test item was calculated based on the chemical oxygen demand (COD) of 2.72 mg O2/mg test item. The biochemical oxygen demand (BOD) of ETP in the test media significantly increased from Day 1 until test-termination after 28 days. A continuous degradation of the test item was determined over the whole test period. At the end of the 28-day test period, the mean biodegradation of ETP amounted to 70%. Thus, ETP was found to be readily biodegradable under the conditions of the test within 28 days.

Executive summary:

It is considered appropriate to address the ready biodegradability data requirement for fatty acids, C12-20 and C12-20 unsatd., 2-ethylhexyl esters by applying read-across from available data on fatty acids, tall-oil, epoxidized, 2-ethylhexylesters (ETP), given that these substances are of similar chemical structure, being long- chain esters with 2-ethyl hexanol.

Based on read-across from ETP, C12 -20 and C12 -20 unsatd., 2 -ethylhexyl esters are considered to be readily biodegradable.

Description of key information

The test item fatty acids, tall-oil, epoxidized, 2-ethylhexylesters (ETP) was investigated for their ready biodegradability in a manometric respirometry test over 28 days according to EU Commission Directive 92/69 EEC, C.4-D (1992) and OECD Guideline for Testing of Chemicals No. 301 F (1992).

The percent biodegradation of the test item was calculated based on the chemical oxygen demand (COD) of 2.72 mg O2/mg test item. The biochemical oxygen demand (BOD) of ETP in the test media significantly increased from Day 1 until test-termination after 28 days. A continuous degradation of the test item was determined over the whole test period. At the end of the 28-day test period, the mean biodegradation of ETP amounted to 70%. Thus, ETP was found to be readily biodegradable under the conditions of the test within 28 days.

Read across from ETP. Both substances are of similar structure, being long-chain esters with 2-ethyl hexanol. See section 13 for a, attached document with a read across justification.

The substance Fatty acids, C12 -20 and C12 -20 -unsatd., 2 -ethylhexyl esters is therefore considered to be readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable