Reaction mass of 3-O-acetyl-1,5-anhydro-4-butyl-2,4-dideoxy-2-methyl-D-xylitol and (2R,3S)-2-methyloctane-1,3-diyl diacetate

Endpoint summary

Description of key information

For Jessemal the following results were derived:

Species	Method	Result	Remarks
Fish (C. carpio)	Read-across	96-h LC50: 32 mg/L	Key study, Rel. 2. Value derived from read-across to Jasmal (CAS# 18871 -14 -2, tested in an OECD TG 203 study).
Daphnia magna	Read-across	48-h EC50: 78 mg/L	Key study, Rel. 2. Value derived from read-across to Jasmal (CAS# 18871 -14 -2, tested in an OECD TG 202 study).
Green algae (P. subcapitata)	Read-across	72-h ErC50: 58 mg/L 72-h ErC10: 8.8 mg/L 72 -h NOErC: 7.0 mg/L	Key study, Rel. 2. Value derived from read-across to Jasmal (CAS# 18871 -14 -2, tested in an OECD TG 201 study).
STP microorganisms	Read-across	28-d NOEC: 100 mg/L	Key study, Rel. 2. Value derived from read-across to Jasmal (CAS# 18871 -14 -2, tested in an OECD TG 301F study).

Additional information

The aquatic toxicity is assessed based on read-across from Jasmal to Jessemal. The executive summaries of the source information are presented in the respective Endpoint summaries of the species. The read across rationale is presented below including all aquatic species.

Aquatic toxicity of Jessemal based on read across from data available for Jasmal (CAS #18871-14-2)

 

Introduction and hypothesis for the analogue approach

For the multi-constituent substance Jessemal all constituents > 1% are identified. The substance consists mainly of two sub-groups of constituents, Tetrahydropyran acetate -like constituents, and Branched alkyl diacetates-type.For Jessemal no experimental aquatictoxicity data are available.In accordance with Article 13 of REACH, lacking information can be generated by means other than experimental testing, i.e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across.For assessment of the aquatic toxicity of Jessemal, the analogue approach is selected because for one of the constituents, Jasmal, aquatic toxicity data is available which can be used for read-across.

Hypothesis: Jessemal has the same aquatic toxicity as Jasmal.

Available information: Jasmal’s aquatic toxicity was tested infish, aquatic invertebrates and aquatic algae according to OECD TG 203, 202 and 201 all Rel. 1, respectively. The NOEC for micro-organism was derived from the Ready biodegradability test (OECD TG 301F, Rel. 1), where no effects on micro-organisms is anticipated in view of the ready biodegradability of the substance.Short-term effect values for Jasmal were determined to be in the range of 10-100 mg/L for fish, Daphnia, algae and micro-organism. EC10 and NOEC values in the algae and micro-organism studies were >1 mg/L. All tests were performed according to current OECD guidelines and in compliance with GLP criteria.

In more detail:

A fish acute toxicitytest was performed according to OECD TG 203 and in compliance with GLP. In a semi-static test set-up, groups of fish (C. carpio) were exposed for 96 hours to 5 concentrations of test substance prepared from a saturated solution of the test material at a loading rate of 100 mg/L. Measured concentrations ranged from 81 - 100 % of nominal in fresh solutions, but decreased to 76 - 88 % of nominal during the refreshment period of 24 hours. Therefore, average exposure concentrations were calculated, however, the mean of these average concentrations was found to be within 80 - 99 % of nominal. Incidences of mortality and clinical effects were recorded for the control and each test group at t=2, 24, 48 and 72 hours. The 96 h LC50 was determined at 32 mg/L based on nominal concentrations.

The data is considered to be reliable without restrictions (Klimisch 1).

An acute Daphniastudy was performed according to OECD TG 202 and in compliance with GLP criteria.In a static test set-up, groups of daphnids were exposed for 96 hours to 5 concentrations of test substance prepared from a saturated solution of the test material at a loading rate of 320 mg/L.Mean measured concentrations, determined as TOC, ranged from 91 - 110 % of nominal at 0 hours and 88 - 112 % of nominal at 48 hours. Daphnia mobility was determined at 24 and 48 hours after the start of exposure. The 48-h EC50 was determined to be 78 mg/L inDaphnia magna,based on nominal concentrations. Based on the lack of specific analysis to confirm test substance concentrations, the data is considered to be reliable with restrictions (Klimisch 2).

A freshwater algaestudy was performed according to OECD TG 201 and in compliance with GLP criteria.Algae (P. subcapitata) were exposed for 72 hours to 5 concentrations of the test substance, prepared from a saturated solution of the test material at a loading rate of 100 mg/L. Samples were taken from all treatments at t = 0 , 24 and 72 h and analysed. Measured concentrations at test initiation ranged from 89 - 101% of nominal, and decreased to 78 - 88% of nominal after 24 hours and 0.07 - 10% of nominal at test end. Therefore time-weighted average (TWA) concentrations were calculated and used for expression of endpoints. Nominal concentrations of 10, 18, 32, 56 and 100% of the saturated solution prepared at 100 mg/L corresponded with 3.3, 7.0, 11, 8.0, 21 and 48 mg/L TWA concentrations, respectively.  Statistically significant inhibition of growth rate was found at TWA concentrations of 7.0 mg/L and higher, however, the effect observed at 7.0 mg/L was considered biologically irrelevant (<10%). Therefore this value was used as NOEC. In none of the test concentrations inhibition of growth rate >= 50% was reached. The ErC50 and ErC10 based on TWA concentrations were 58 and 8.8 mg/L, respectively. The data is considered to be reliable without restrictions (Klimisch 1).

Micro-organisms: The STP toxicity data are available from a standard inhibition control in the OECD TG 301D test. Based on the percent degradation of sodium benzoate when tested in combination with the test substance (toxicity control), it is concluded that the test substance is not toxic to microorganisms at a concentration of 100 mg/L (>25% degradation based on ThOD) and the NOEC is set at this concentration.

Target chemical and source chemical(s)

Chemical structures of the target chemical and the source chemical(s) are shown in the data matrix, including physico-chemical properties.

Purity / Impurities

The major and minor constituents of Jessemal are presented in the Data matrix. The impurities < 10% are grouped based on their resemblance with Tetrahydropyran acetate -like constituents, and Branched alkyl diacetates-type.

Analogue approach justification

According to Annex XI section 1.5, read across can be used to replace testing when the similarity can be based on a common backbone and a common functional group. When using read across the result derived should be applicable for C&L and/or risk assessment and it should be presented with adequate and reliable documentation, which is presented below

Analogue selection: For Jessemal the substance Jasmal was selected as source chemical for read-across becauseJessemal‘sconstituents arethe same and/orvery similar to Jasmal’sand for Jasmal experimental aquatic toxicity information is available.

Structural similarities and differences:Jessemal andJasmal are both reaction masses containing similar Tetrahydropyran acetate-like constituents with molecular weight of 214. Jessemal also contains constituent of Branched alkyl diacetates with molecular weights of 244. These diacetates have one additional acetic ester and have an open ring structure not present in Jasmal. Jessemal hastwo minor impurities just exceeding the 1% level, one being the alcohol derivative of the Tetrahydropyran acetates and the other one of the Branched alkyl diacetates, which will not be addressed further being only very minor constituents.

Bioavailability:Jessemal and Jasmal have similar bioavailability because these have similar constituents and impurities and comparable log Kow values (≤0.5 difference)

Reactivity and Mode of action: Jessemal and Jasmal are expected to have the same reactivity because their constituents and impurities are allesters without any additional reactive functional groups.

Conversion of the effect values from Jasmal to Jessemal: No log Kow correction needs is performed.The weighted log Kow of Jessemal is 3.73 (3.5-4.2), the log Kow of Jasmal was determined to be 3.2 to 3.7. As the difference is ≤0.5, no conversion for difference in log Kow is deemed necessary.

Uncertainty of the prediction:There are no uncertainties other than those already addressed in the previous sections.

Data matrix

The relevant information on physico-chemical properties and ecotoxicological characteristics are presented in the data matrix below.

Conclusions on aquatic toxicity for hazard and risk assessment

For Jessemalno aquatic toxicity information is available. Jasmal is an analogue for which aquatic toxicity is available, which can be used for read-across to fill this data gap. When using read-across, the result derived should be applicable for C&L and/or risk assessment, and be presented with adequate and reliable documentation. This documentation is presented in the current text. For the analogueJasmal, the lowest acute effect value is 32 mg/L as observed in fish (OECD TG 203). EC50 values in Daphnia and algae were 78 and 58 mg/l, respectively (OECDTG 202 and 201, respectively. For algae an EC10 of 8.8 mg/L is found (OECDTG 201).

 

Data matrix to support the read across to Jessemal from Jasmal for aquatic toxicity

Name	Jessemal	Tetrahydropyran acetates	Jasmal + 3 other similar impurities	Branched alkyl diacetates	Other branched alkyl diacetates (4 impurities)
Read-across	Target	Target Major constituent	Source (and impurity)	Target Minor  constituent	Target impurities
Chemical structures	Not applicable
Typical conc. (%)	Not applicable	20-40	<23	10-20	<22
CAS #	Not applicable	38285-49-3	18871-14-2	67634-09-7	--
Einecs	945-946-3		242-640-5
REACH registration	2018		Registered
MW	Not applicable	214	214	244	244
Phys-chem*
Log Kow	3.5 #(exp.)	3.2 (est.)	3.2 - 3.7 (exp.)	3.7 (est.)	3.7 (est.)
Ws (mg/L)	714.1 (exp.)	67.8 (est.)	214.9 (exp.)	17.8 (est.)	17.8 (est.)
Aquatic toxicity
LC50 for fish in mg/l	32 (Read across)	32 (Read across)	32 (OECD TG 203)	32 (Read across)	32 (Read across)
EC50 for Daphnia in mg/l	78 (Read across)	78 (Read across)	78 (OECD TG 202)	78 (Read across)	78 (Read across)
EC50 for algae in mg/l	58 (Read across)	58 (Read across)	58 (OECD TG 201)	58 (Read across)	58 (Read across)
EC10 for algae in mg/l	8.8 Read across)	8.8 Read across)	8.8 (OECD TG 201)	8.8 Read across)	8.8 Read across)
NOEC Micro-organism in mg/l	100 (Read across)	100 (Read across)	100 (OECD TG 301F)	100 (Read across)	100 (Read across)

*  Episuite v4.11 unless stated otherwise (i.e. ‘exp.’); #Log Kow of the major constituent is used, the log Kow range is 3.5 to 4.2.