2-Propenoic acid, γ-ω-perfluoro-C8-14-alkyl esters

Endpoint summary

Additional information

STABILITY

Phototransformation in air

Photodegradation in the air: a study on the photodegradation in the air of 8 -2 FTOH (2POE as cited in the study report) is available (Telomer Research Program, 2003).

Since preliminary tests showed difficulties in testing because of the low vapour pressure of the substance of study, an alternative approach was tried with 2 surrogates of 2POE. Fluorinated alcohols of short-chain (CF3CH2CH2OH = TFP and C6F13CH2CH2OH = TDO) were used to extrapolate the rate constant and lifetime of 8 -2 FTOH. The studies have been carried out using two photoreactors: a 150 L Teflon bag irradiated by lamps at CNRS-Orleans for the kinetics and mechanistic studies, and the 200 m³ European photreactor, EUPHORE, irradiated by sunlight at Valencia (Spain) also for the mechanistic study. Same values were obtained for the two substances tested, therefore a value of K = 1.06x10E-12 +/-0.2 cm³/molec*s for the 8-2 FTOH molecule was recommended. The major products observed were the fluoroaldehydes CnF(2n+1)CH2CHO and CnF(2n+1)CHO in the presence and absence of NOx. It was observed that these two type of compounds are succesively formed and CF2O is the end product. PAN like compounds (e.g. CF3CH2C(O)OONO2) were also observed in the presence of NOx. This mechanism can be generalised for the larger fluoroalcohols, including 2POE.

Hydrolysis

Key study with 8:2 fluorotelomer acrylate

Hydrolysis as a function of pH was determined according to OECD Guideline No. 111 and Council Regulation (EC) No. 440/2008, Method C.7 for the test item Fluowet AC 800 from 2012-11-06 to 2013-04-23 atDr.U.Noack-Laboratorien, 31157 Sarstedt, Germany.

Analyses of the test item were performed via GC-MS on a Rtx-1301 capillary column using an external standard. The method was validated with satisfactory results in regard to linearity, accuracy, precision and specificity.

The study was conducted with a test item concentration of 1000 µg/L in buffer solution pH 1.2 at a temperature of 37 °C and in buffer solutions of pH 4, 7 and 9 at temperatures of 20, 30 and 50 °C, respectively. Acetonitrile was used as co- solvent at a content of 10 % (v/v), as the test item was not readily soluble in the test system at the required test concentration. Samples were taken at test start (0 h) and at 12 to 15 spaced points until test end. Buffer solutions were analysed at test start and test end and there was no analytical interference with the test item.

Reaction rate constants and half-lives were calculated from the analysed samples and are presented in Table 1. The test item Fluowet AC 800 showed only moderate elimination at all tested conditions.

Analysis of the expected primary transformation product 2-(Perfluorooctyl)ethyl alcohol (8:2 FTOH) could not be performed within this study due to the complexity of the analysis. Nevertheless, samples for determination of this transformation product were taken, stored and analyses will be performed in a separate study as soon as an adequate analytical method will be available. The secondary transformation product PFOA could not be determined above the limit of quantification (LOQ_M, 2 µg/L) and was therefore regarded as not relevant.

Reaction Rate Constants and Half-lives ofFluowet AC 800

	pH 1.2	pH 4			pH 7			pH 9
	37 °C	20 °C	30 °C	50 °C	20 °C	30 °C	50 °C	20 °C	30 °C	50 °C
Reaction rate constantkobs [1/s]	1.00 x 10^-6	9.25 x 10^-7	1.70 x 10^-6	1.36 x 10^-6	5.92 x 10^-7	1.20 x 10^-6	9.72 x 10^-7	8.58 x 10^-7	1.60 x 10^-6	2.04 x 10^-6
Half-lifeT½[h]	193	208	114	142	325	160	198	224	120	94.4
Half-lifeT½[d]	8.04	8.67	4.73	5.92	13.5	6.67	8.25	9.33	5.00	3.93

Key study with 10: fluorotelomer acrylate

Hydrolysis as a function of pH was determined according to OECD Guideline No. 111 and Council Regulation (EC) No. 440/2008, Method C.7 for the test item from 2012-10-09 to 2013-04-19 atDr.U.Noack-Laboratorien, 31157 Sarstedt, Germany.

Analyses of the active ingredient of the test item were performed via GC-MS on a Rtx-1301 capillary column, using an external standard. Analyses of the transformation product perfluorodecanoic acid (PFDA) were peformed via LC-MS/MS on a silica based C18 reversed phase column, also using an external standard. Both methods were validated with satisfactory results in regard to linearity, accuracy, precision and specificity

The study was conducted with a test item concentration of 1000 µg/L in buffer solution pH 1.2 at a temperature of 37 °C and in buffer solutions of pH 4, 7 and 9 at temperatures of 20, 30 and 50 °C, respectively. Acetonitrile was used as co- solvent at a content of 10 % (v/v), as the test item was not readily soluble in the test system at the required test concentration. Samples were taken at test start (0 h) and at 12 to 13 spaced points until test end. Buffer solutions were analysed at test start (only GC) and test end and there was no analytical interference with the test item.

At environmental typical temperatures the test item Fluowet AC 1000 showed no significant hydrolysis. At elevated temperatures a increasing instability was observed to higher pH values.

Analysis of the expected primary transformation product 2-(Perfluorodecyl)ethyl alcohol (10:2 FTOH) could not be performed within this study due to the complexity of the analysis. Nevertheless, samples for determination of this transformation product were taken, stored and analyses will be performed in a separate study as soon as an adequate analytical method will be available. The secondary transformation product PFDA could not be determined above the limit of quantification (LOQ, 2 µg/L) and was therefore regarded as not relevant.

Reaction Rate Constants and Half-lives ofFluowet AC 1000

	pH 1.2	pH 4			pH 7			pH 9
	37 °C	20 °C	30 °C	50 °C	20 °C	30 °C	50 °C	20 °C	30 °C	50 °C
Reaction rate constantkobs [1/s]	6.83 x 10^-8	n.a.		1.80 x 10^-7	n.a.	1.48 x 10^-7	5.58 x 10^-7	n.a.	1.84 x 10^-7	1.72 x 10^-6
Half-lifeT½[h]	2818			1070		1303	345		1049	112
Half-lifeT½[d]	117			44.6		54.3	14.4		43.7	4.67

Supporting study with 8:2 FTOH

The aqueous stability of the test substance in sterile aqueous solutions buffered at pH 1.2, 4.0, 7.0 and 9.0 was determined. Test systems consisted of the test substance in aqueous buffered solutions in sterilized containers. The test system was incubated in the dark at 50°c at pH 4, 7 and 9 and at 37°C at pH 1.2.

The test substance isstable under the conditions of the test at pH 4, 7 and 9 at 50°C and pH 1.2 at 37°C. The time in which 50% of the test substance will transform is estimated as greater than one year:

t_1/2> 1 year.

BIODEGRADATION

Biodegradation in water: screening tests

In one key study the ready biodegradability of the test itemFluowet AC 800 was determined with a non adapted activated sludge over a test period of 28 days in the Headspace Test. Thestudy was conducted from 2012-12-19 to 2013-02-14, according to OECD 310 and EN ISO 14593 atDr.U.Noack-Laboratorien.The test item was tested at a concentration of35 mg/L in triplicates (test end: 5 replicates). To enhance the solubility of the test item in the test medium triethylene glycol dimethyl ether (triglyme) was used as solvent.The degradation of the test item was followed by specific analysis of the degradation products 8-2 FTOH, 8-2 FTUA, 8-2 FTA and PFOA by LC-MS/MS at test end (day 28). Furthermore the concentrations of the test item at test start and test end was determined by GC-MS analysis of the test medium. Additionally the headspace was sampled at test end to determine the volatile fraction of the test item in the test system.

The biodegradation of the reference item and toxicity control was followed by TIC analyses of the quantity of CO₂produced by the respiration of bacteria. The amount of TIC produced was calculated by correcting the results for endogenous TIC production of the solvent control groups and the blind value of the sodium hydroxide solution. The biodegradation was calculated for each sampling time (Table21toTable22).

To check the activity of the test system and the influence of the solvent aniline with addition of 1 % Triglyme was used asfunctional control. The percentage degradation of the functional control reached the pass level of 60 % after 14 days(Table1).

In the toxicity control, containing test and reference item and 1 % Triglyme, a biodegradation of 35 % was determined after 9 days and 14 days. The biodegradation of the reference item was not inhibited by the test item and Triglymein the toxicity control.(Table1).

Beyond day 14 until test end the calculated biodegradation decreases in the functional control and the toxicity control as the high TIC production by degradation of traces of the solvent Triglyme influenced the calculations. For details see4.2.1.

 

Table1:Biodegradation of the Functional Control and the Toxicity Control

	Biodegradation [%]
Day	1	9	14	21	28
Functional Control Reference Item + 1 % Triglyme	0	59	62	(52)	(25)
Toxicity Control, Test Item + Reference Item + 1 % Triglyme	0	35	35	(26)	(3)

               ( ) calculation of biodegradation influenced by traces of Triglyme

The biodegradation of thetest itemis given inTable2. The results of the specific test item analysis and the analytical results for the metabolites of the test item are summarized. The results indicate a slow biodegradation ofFluowet AC 800, a 8-2 fluortelomer methacrylate, under the test conditions. 2% 8-2 FTOH were formed within the 28 day test duration. Further relevant metabolites in the biotransformation of the test item were formed in amounts < 1%. 8-2-FTOH is expected to be the first transformation product after cleavage of the ester bond. Based on the knowledge about biotransformation of 8-2 FTOH an oxidation under formation of 8-2 FTA follows [Wang et al., 2009]. Further steps in the biotransformation include desaturation under formation of 8-2 FTuA and PFOA. The latter one represents a terminal product in the biotransformation cascade of 8-2 FTOH.

 

 

Table2:         Specific Test Item Analysis – Overview Results

Application concentration:     33.6 mg/LFluowetAC 800correspond to 100%,

                                                        

Sample Day	Matrix	Fluowet AC 800	8-2 FTOH	8-2 FTuA	8-2 FTA	PFOA
Day 0	MTBE Extract	100%	-	-	-	-
Day 28	MTBE Extract	89%	1%	< 1%	< 1%	< 1%
	Extracted              Test Medium	-	1%	< 1%	< 1%	< 1%
	Headspace	< 1%	< 1%	-	-	-

 

 

The test item is classified as
not readilybiodegradable

in the 10-d-window and after 28 days.

 

Two other key studies investigated with the read across and main breakdown product 8:2 FTO shows the following results:

OECD 302B (8:2 FTOH):

---------------

One study on the inherent biodegradation potential of TRP-1989, including results on 8:2 FTOH (CAS No. 678-39-7), is available (Clariant GmbH, 2005). The test was conducted according to OECD Guideline 302B, under GLP conditions. The test item proper, i.e. TRP-1989, is a polymer (perfluoroalkyl acrylic copolymerisate). However, the biotransformation potential was monitored by analysing five residuals and potential transformation products, one of which is 8:2 FTOH (= 8-2 OH). Activated sludge microorganisms were exposed to the polymer at a concentration of 6000 mg/L for a period of 28 days. The biodegradation was followed by analytical measurement of 8:2 FTOH. Measurements of two replicates demonstrated a degradation of 8:2 FTOH with concentrations of 42.0 and 41.9 µg/L on Day 0 decreasing to 37.4 and 8.3 µg/L on Day 7 and below the limit of detection on Day 14. Thus 8:2 FTOH was eliminated/degraded to 100%. Due to the fact that 8:2 FTOH is highly volatile a volatility control was conducted in parallel and demonstrated that no test substance was lost.

OECD 311 (8:2 FTOH):

---------------

One study on the anaerobic Biodegradability of Organic Compounds in Digested Sludge of 8-2 FTOH (CAS No. 678-39-7) is available (Clariant GmbH, 2007). The test is non-GLP but was conducted according to OECD Guideline 311. The biotransformation potential was monitored by analysing 3 potential transformation products: 8 COOH (PFOA), 8-2 COOH, 8-2 U COOH. Digested sludge was exposed to the test item concentration of 10 mg/L for a period of 63 days. The biodegradation was followed by analytical measurement of all analytes and parent substance. Measurements of three replicates demonstrated a degradation of 8:2 FTOH of 42.7% after 63 days. In the headspace gas no biotransformation products could be detected during the course of the study.

Two supporting studies regarding OECD Guideline 301D and 301C shows that the 8:2 FTOH is not readily biodegradable.

Biodegradation in water and sediment: simulation tests

Waiving according to "column 2" in Annex VIII and IX of REGULATION (EC) No 1907/2006 (CSA does not indicate need for further investigations). The study need not be conducted because a direct and indirect exposure of sediment is unlikely. Substance has a low exposure to water. A simulation test is not warranted because of the exposure situation to water and the results of the sreening tests and soil degradation tests made with 8:2 FTAc and 8:2 FTOH.

Biodegradation in soil

OECD 307 (8:2 FTOH):

---------------

One study on the aerobic transformation in soil of the polymer TRP-1989 which contains residual 8-2 FTOH (CAS No. 678-39-7) is available (Clariant GmbH, 2011a). The test was conducted according to OECD Guideline 307 and it fulfills the GLP criteria. The biotransformation potential was monitored by analysing 3 potential transformation products: 8 COOH (PFOA), 8-2 COOH (FTA), 8-2 U COOH (8 -2 FTuA). The initial test substance concentration in the test soil was 1000 mg/kg soil dw. The study was conducted over 24 months. The biodegradation was followed by analytical measurement of all analytes and parent substance. PFOA formed after 2 years is < 60% Mol-% of the amount of residual 8 -2 FTOH at Day 0.

After 104 days (ca. 3 months) 8 -2 FTOH could no longer be measured as the concentration was below LOQ and LOD. After Day 104, PFOA is still being formed, this is an indication of slow migration of 8 -2 FTOH out of the polymer. If any would come from the acrylate cleavage in the polymer the cleavage rate would be very low, otherwise 8 -2 FTOH would have been measureable after Day 104.

In the headspace gas no biotransformation products could be detected during the course of the study. For the calculation of DT50 values two models were used, both models fit the measured data well but the overall outcome is somewhat different. The worst cases were DT50 values for the initial available residual alcohol of 27 days and 13.5 days taking into account all diffused alcohol that has migrated from the polymer (absorbed 8-2 FTOH).

 

Landfill simulation study (8:2 FTOH):

-----------------------------

A landfill simulation study with coated fabric (cotton and polyester) was carried out to mimic a residence time of 30-40 years by accelerating the ageing process through higher water circulation when compared to a typical landfill (Clariant GmbH, 2011b). No guideline is available at the moment and the test is non-GLP but it is a well documented report which meets basic scientific principles. The time span of 9 month in the simulation study corresponds to 31 years on a landfill. The test item was cotton and polyester coated with TRP-1255. TRP-1255 contains as active ingredient the polyfluorinated acrylate polymer TRP-1989. The low molecular weight polyfluorinated telomer substances such as 8-2 FTOH can be found as residuals in the polyfluorinated acrylate polymer and these may be transformed to polyfluorinated acids such as PFOA which are persistent in the environment. The biotransformation potential was monitored by analysing 3 potential transformation products: 8 COOH (PFOA), 8-2 COOH (FTA), 8-2 U COOH (FTuA) in leachate samples and headspace gas. The available test item amounts were 5.3 mg 8-2 FTOH in the lysimeters filled with cotton samples and 3.1 mg in the lysimeters filled with polyester samples. The biodegradation was followed by analytical measurements of all analytes and parent substance. The landfill simulation study shows that the formation of PFOA from residual 8-2 FTOH in the TRP-1989 included in the textile coating is very slow; the yield at the study end was 0.02 Mol-% (cotton) and 0.05 Mol-% (polyester) PFOA. More than 98.5 Mol-% (polyester) and 99.1 Mol-% (cotton) of residual 8-2 FTOH remained in the reactor after the 9-month study. The DT50 was estimated to be more than 38 years.

BIOACCUMULATION

In one key study Butt et al. published the biotransformation of the 8:2 fluorotemoler acrylate in rainbow trout. The bioaccumulation and biotransformation of the 8:2 fluorotelomer acrylate was investigated in rainbow trout via dietary exposure. Very low levels of the 8:2 FTAc were detected in the internal tissues and feces, suggesting that the 8:2 FTAc was rapidly biotransformed in the gut or liver. Similarly, low concentrations of the 8:2 fluorotelomer alcohol (FTOH) were accumulated in the fish tissues. In a second publication Butt et al show showed that the 8:2 FTAc is rapidly biotransformed in the liver and stomach S9 fractions, with formation of the 8:2 FTOH observed within 30s to 1 min of incubation.

 

A supporting study with the read across substance 8:2 FTOH (main degradation product) published by MITI showed that the BCF of 8: FTOH is between 200 – 1100 (Test Concentration - 1st Concentration: 10 microg/L) or between 87 – 310 (Test Concentration - 2nd Concentration: 1 microg/L)

Brandsma: Dietary exposure of rainbow trout to PFOSA does not result in a significant accumulation of PFOSA (BMF of 0.023). The presence of PFOS showed that rainbow trout is able to metabolize PFOSA into PFOS. Half-lives of PFOSA and PFOS were 6.0 ± 0.4 and 16.9 ± 2.5 d, respectively. The fluorotelomer alcohols 8:2 FTOH and 10:2 FTOH are also rapidly metabolized to the fluorotelomer acids (8:2 FTCA, 10:2 FTCA) and the unsaturated acids (8:2 FTUCA, 10:2 FTUCA), respectively. Half-lives were 3.7 ± 0.4, 2.1 ± 0.5, 3.3, and 1.3 d for 10:2 FTCA, 10:2 FTUCA, 8:2 FTCA, and 8:2 FTUCA, respectively. Small quantities of PFOA and PFDA were also detected in rainbow trout exposed to 8:2 and 10:2 FTOH. The results indicate that the neutral precursors studied are rapidly transformed and eliminated by fish while their transformation products are generally more bioaccumulative.

TRANSPORT AND DISTRIBUTION

Adsorption / desorption

For the substance C8-2 FTOH (fluorinated telomer alcohol, CAS No. 678-39-7) adsorption coefficients on quartz as well as logarithmic partition coefficients humic acid-air were determined using the inverse gas chromatography (ICG) method.

Versions for other alcohols (cut + paste):

C4-2 FTOH:

Short description of key information:

Koc (m3/m2), quartz 90% relative humidity:

9.19E-03 at 5 °C

3.82E-03 at 15 °C

1.05E-03 at 25 °C

4.86E-04 at 35 °C

1.84E-04 at 45 °C

8.75E-05 at 55 °C

ln K HA/air (L/kg) at 98% relative humidity of HA (humic acid):

11.3 at 5 °C

10.5 at 15 °C

9.62 at 25 °C

8.69 at 35 °C

7.9 at 45 °C

Discussion:

For the substance C4-2 FTOH (fluorinated telomer alcohol) adsorption coefficients on quartz as well as logarithmic partition coefficients humic acid-air were determined using the inverse gas chromatography (ICG) method.

C6-2 FTOH:

Short description of key information:

Koc (m3/m2), quartz 90% relative humidity:

5.30E-02 at 5 °C

2.17E-02 at 15 °C

6.11E-03 at 25 °C

2.40E-03 at 35 °C

7.73E-04 at 45 °C

3.43E-04 at 55 °C

ln K HA/air (L/kg) at 98% relative humidity of HA (humic acid):

12.4 at 15 °C

11.2 at 25 °C

10.3 at 35 °C

9.41 at 45 °C

Discussion:

For the substance C6-2 FTOH (fluorinated telomer alcohol) adsorption coefficients on quartz as well as logarithmic partition coefficients humic acid-air were determined using the inverse gas chromatography (ICG) method.

C10-2 FTOH:

Short description of key information:

Koc (m3/m2), quartz 90% relative humidity:

1.134 at 15 °C (extrapolated)

2.56E-01 at 25 °C

5.05E-02 at 35 °C

1.59E-02 at 45 °C

4.69E-03 at 55 °C

Discussion:

For the substance C10-2 FTOH (fluorinated telomer alcohol) adsorption coefficients on quartz were determined using the inverse gas chromatography (ICG) method.

Key study regarding OECD Guideline 106:

The adsorption and desorption isotherm showed a strong positive monotonic relationship between log Ce and log X/m, indicated by the correlation coefficients being close to 1. These values characterise the test substance as slightly mobile (Koc 500-4000) to non-mobile (Koc>4000) in the four soils and one sediment used in this study. Mass balance for the four soils and one sediment were in the range 86 to 96%.

Henry's Law constant

The air/water partition coefficient at ambient temperature of the substance C8-2 FTOH (fluorinated telomer alcohol, CAS No. 678 -39 -7) was calculated with the use of the LSER approach. The coefficients for the underlying Abraham equation were determined experimentally. In addition, QSAR calculations with 4 different models were performed. The results for 4 fluorinated telomer alcohols

are presented in the table:

 

Method	C4-2 FTOH	C6-2 FTOH	C8-2 FTOH
Experiment	-1.52	-0.56	-
LSER	-1.51	-0.72	0.04
COSMOTherm	-1.37	-0.73	-0.31
SPARC	-1.88	-1.47	-0.83
HENRYWIN I	-0.65	0.79	2.23
HENRYWIN II	-0.17	1.83	3.83

Comparison of experimental data and calculated data for C4 -2 and C6 -2 FTOH reveals that the LSER calculations result in the most reliable estimation. They are based on a large number of different experimental partition data for the Fluoro-telomers.