Reaction mass of 1-methyl-4-(1-methylethylidene)cyclohexyl acetate and p-menth-1-en-8-yl acetate

Endpoint summary

Description of key information

Overview of aquatic toxicity data for Terpinyl Acetate multi based on data from Terpinyl Acetate alpha, it key constituent

Species	Method	Results	Remarks
Desmodesmus subspicatus	Read across from key constituent Terpinyl Acetate alpha.	72h-EC50 (growth rate): 6.9 72h-EC10 (growth rate): 4.1	The source was tested according to OECD TG 201. Results based on geometric mean measured concentrations Key study; Rel. 2 because of read across
Daphnia magna	Read across from key constituent Terpinyl Acetate alpha	48h-EC50: >10	The source was tested according to OECD TG 202 using flow through conditions. Key study, Rel. 2 because of read across
Oncorhynchus mykiss	Read across from key constituent Terpinyl Acetate alpha	96h-LC50: >11	The source was tested according to OECD TG 203 using flow through conditions. Key study, Rel. 2 because of read across
Activated sludge from domestic waste	Read across from key constituent Terpinyl Acetate alpha	28d-NOEC: 100 mg/l	The source results are derived from the ready biodegradability test (OECD TG 301F) in which no effects are anticipated at 100 mg/l because the substance is readily biodegradable. Key study, Rel. 2 because of read across

Additional information

The information for Terpinyl Acetate multi can be derived from Terpinyl Acetate alpha because the alpha is the main constituent of the multi. The read across justification and documentation is presented below.

Aquatic toxicity of Terpinyl Acetate multi using read across from Terpinyl Acetate alpha (CAS no.80-26-2).

Introduction and hypothesis for the analogue approach

Terpinyl Acetate multi’s constituents have a hydrocarbon backbone to which an acetic ester is attached. For its key constituent aquatic toxicity information is available but not for the others constituents. In accordance with Article 13 of REACH, lacking information can be generated by i.e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across. For assessing the aquatic toxicity of Terpinyl Acetate multi the analogue approach is selected because for the analogue Terpinyl Acetate alpha acute aquatic toxicity information is available which can be used for read across.

Hypothesis: Terpinyl Acetate multi has the same acute aquatic toxicity as Terpinyl Acetate alpha. Conversion is not needed because the log Kow of the constituents are all around 4.4.

Available information: For Terpinyl Acetate alpha acute aquatic toxicity data are available according to OECD TG 201,202 and 203 (Klimisch 1). The lowest value acute toxicity value is the EC50 for algae: 6.9 mg/l. The NOEC/EC10 is 4.3, respectively.

Target chemical and source chemical

Chemical structures of Terpinyl Acetate multi and key constituent Terpinyl Acetate alpha are shown in the data matrix, including physico-chemical properties and other aquatic toxicity values thought relevant for the read across.

Purity / Impurities

Terpinyl Acetate multi is a reaction mass containing a mixture of isomers, which differ on the site where the ester is attached. An overview of the constituents is presented in the data matrix. The impurities are < 10%.

Analogue approach justification

According to Annex XI 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 justification: For Terpinyl Acetate multi its key constituent Terpinyl Acetate alpha is selected because it is the main constituent for which acute toxicity information is available.

Structural similarities and differences: Terpinyl Acetate multi’s key constituent is Terpinyl Acetate alpha and this is the same substance. The read across is to Terpinyl acetate gamma and the impurities cis and trans-beta Terpinyl acetate (the latter having the ester bond at the same spot in the structure as gamma) is based on the similar hydrocarbon backbone and the same acetate ester group. The presence of the double bond in the cyclohexyl ring and absence of this bond in the gamma isomer is discussed in the aquatic reactivity.

Bioavailability: Terpinyl Acetate multi’s constituents, alpha and gamma have similar bioavailability based on the similarity in chemical structure, molecular weight and log Kow values (all close to 4.4).

Aquatic reactivity: Terpinyl Acetate multi constituents all are considered to have the same ester reactivity as presented by ECOSAR and therefore resulting in the same aquatic toxicity values. The double bond in the ring versus outside the ring for the Terpinyl Acetate alpha and gamma, respectively, did not show an impact in ECOSAR. ECOSAR predict a 0.13 higher log Kow (4.467 and 4.337 for gamma and alpha, respectively), which is considered insignificant when assessing the aquatic toxicity.

Uncertainty of the prediction: There are two impurities cis and trans-beta terpinyl acetate making up together ca 10%. These have a log Kow around 4.4 are categorised similarly to the alpha and the gamma isomers and therefore will present the same aquatic toxicity as the alpha and gamma isomers.

Data matrix

The relevant information on physico-chemical properties and other environmental fate properties are presented in the Data Matrix below.

Conclusions for Aquatic toxicity

For Terpinyl Acetate multi as such no aquatic toxicity data are available. For its key constituent Terpinyl Acetate alpha acute aquatic toxicity information is available, which can be used for read across to the other constituents. This is based on structural similarity, Ester categorisation by ECOSAR and log Kow similarity

Final conclusion: Terpinyl Acetate multi-constituents has an LC50 fish, EC50 Daphnia and EC50 algae of > 11, >10 and 6.9 mg/l; it has an EC10/NOEC of 4.1 mg/l

 

Data matrix to support Aquatic toxicity read across to Terpinyl Acetate multi constituents from Terpinyl Acetate alpha

Common names	Terpinyl Acetate multi	Terpinyl Acetate alpha	Terpinyl Acetate gamma
	Target	Target	Target
Chemical structures	See constituents
Constituent % typical values	>=84%	55-75	14-26
Cas no	See constituents	80-26-2	10235-63-9
EINECS no	904-693-9	201-265-7	233-564-3
REACH registration	Yes	Yes	No
Empirical formula	C12H20O2	C12H20O2	C12H20O2
Molecular weight	196	196	196
Physico-chemical data
Physical state	Liquid	Liquid	Likely a liquid
Log Kow	4.4	4.4	Read across from Terpinyl Acetate alpha
Log Kow EpiSuite		4.337	4.467
Environmental Fate
Log Koc	Read across from Terpinyl Acetate alpha	2.79
Biodegradability	Read across	Readily	Read across from Terpinyl Acetate alpha
Aquatic toxicity
Acute fish toxicity: LC50 (mg/L)	Read across from Terpinyl Acetate alpha	>11 (OECD TG 203)	Read across from Terpinyl Acetate alpha
Acute Daphnia: EC50 mg/l	Read across from Terpinyl Acetate alpha	>10 (OECD TG 202)	Read across from Terpinyl Acetate alpha
Acute Alga: EC50 in mg/l	Read across from Terpinyl Acetate alpha	6.9 (OECD TG 201)	Read across from Terpinyl Acetate alpha
Long-term Algae EC10/Algae	Read across from Terpinyl Acetate alpha	4.1 (OECDTG 201)	Read across from Terpinyl Acetate alpha