Alcohols, C8-14, γ-ω-perfluoro

Endpoint summary

Additional information

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

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 is stable 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 in water: screening tests

OECD 302B:

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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 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:

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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 soil

OECD 307:

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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:

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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.

MITI :

Published Result:

Chemical substance determined to be persistent but not highly bio-accumulative

Judgement: Non-biodegradability

Remarks: None reported

Test Method: Bio-concentration test

Acute Toxicity Test

LC50 (96 hr): > 125 mg/L

LC50 (48 hr): Not Reported

Species: Rice fish (Oryzias latipes)

Flow-through Test

Test Equipment: Improved type for a volatile substance

Test period. 60 days

Species: Carp (Cyprinus carpio)

Lipid Content (%): Not Reported

Lipid Content (%) - start of testing: 4.2

Lipid Content (%) - end of testing: 3.97

Test Concentration - 1st Concentration: 10 microg/L

BCF– 1st Concentration: 200 - 1100

Test Concentration - 2nd Concentration: 1 microg/L

BCF– 2nd Concentration 87 - 310

Partition coefficient(noctanol/ water): not reported

Minimum (log Pow)

Maximum (log Pow)

Average (log Pow)

Brandsma:

The present study did not allow the detection of FTOHs because no validated method was available at the time. Therefore, this study should be regarded as a preliminary range finding investigation, which focused on the non-volatile transformation products in the fish. Exposure to 8:2 and 10:2 FTOHs via food resulted in a series of perfluoroalkyl metabolites (FTCAs and FTUCAs) as shown in Fig. 1. This figure shows the growth-corrected concentrations of FTCAs and FTUCAs in rainbow trout muscle samples over a 30-d dietary exposure to 6.7 lg g1 wet wt 8:2 FTOH and 5.0 lg g1 wet wt 10:2 FTOH, following by a 30-d depuration phase. The predominant metabolites are 10:2 FTCA and 10:2 FTUCA, followed by 8:2 FTCA and 8:2 FTUCA. This is consistent with earlier studies, which observed similar metabolites during exposure of 8:2 FTOH to rats and mice (Hagen et al., 1981; Kudo et al., 2005; Martin et al., 2005; Fasano et al., 2006). The same metabolites were also found in the 8:2 FTOH in vitro metabolism study with trout hepatocytes and the 8:2 FTAc in vivo metabolism study with rainbow trout (Nabb et al., 2007; Butt et al., in press). Butt et al. (in press) found that only low concentrations of 8:2 FTOH were accumulated in rainbow trout tissues following dietary exposure to 8:2FTAc. In addition, Butt et al. (in press) measured an 8:2 FTOH-glucuronide conjugate at relatively high concentrations in the bile and feces of the FTAc exposed trout. Conjugate metabolites (e.g. glucuronide and glutathione) and 7:3 FTCA reported in earlier studies were not measured in this study. The fish extract were only measured for the compounds shown in Table 1. Small quantities of PFOA and PFDA were also detected in rainbow trout exposed to 8:2 and 10:2 FTOH. This indicates that rainbow trout can metabolize FTOH to the more stable PFCAs. The concentrations appear to be very low, just above the detection limit (1 ng g1). Therefore, no calculation could be done concerning uptake and depuration parameters. This biotransformation observed in rainbow trout is consistent with previous animal studies which have shown that small quantities of PFOA and PFNA can be formed after exposure to 8:2 FTOH (24–28). PFNA was not detected in this study. Biotransformation of 8:2 FTAc and 8:2 FTOH to PFOA was also observed in exposed trout and trout hepatocytes, respectively (Nabb et al., 2007; Butt et al., in press) and Butt et al. (2010b) showed FTCAs and FTUCAs formed PFCAs. Butt et al. (in press) found that PFNA was formed in much lower concentrations than PFOA (1%), thus given that PFOA levels were just above the detection limit, the lack of detection of PFNA is not surprising. The concentrations found after 30 d for 10:2 FTCA are significantly higher than those of 8:2 FTCA (Fig. 1). The assimilation and the metabolism of the FTOHs was a relatively fast process detectable after 1 d of exposure. This is consistent with the trout exposure study of Butt et al. (in press) which observed 8:2 FTCA within 1 h after 8:2 FTAc dosing. Nabb et al., 2007 reported halflives after in vitro metabolism of 8:2 FTOH in rat, mouse, trout and human hepatocytes of 9.9, 13, 36 and 103 min, respectively. The fact that 8:2 FTCA and 8:2 FTUCA are almost at steady-state throughout the uptake (Fig. 1) seems consistent with a fast biotransformation of both the 8:2 FTOH, 8:2 FTCA and 8:2 FTUCA. After 10 d the 8:2 FTCA and 8:2 FTUCA decreased to concentrations below the LOD, while this took 20 and 30 d, respectively for the 10:2 FTCA and 10:2 FTUCA; 10:2 FTCA showed the longest half-life (3.7 ± 0.4 d). The others showed half-lives ranging from 1.3 to 3.3 d. Interpretations of the half-lives of 8:2 FTCA and 8:2 FTUCA should be done with care, because the calculations were only possible by linear regression through two growth-corrected concentration points, and no standard error could be calculated. The longer half-lives of the long-chain FTCAs are consistent with the results of Martin et al. (2003a,b). Half-lives reported in the literature for PFOA and PFDA, 5.2 and 14 d, respectively, show that the halflives of the FTCAs are comparable with that of PFOA, and, consequently, lower than that of PFDA. The differences in half-lives between chain-lengths may also explain why the 10:2 FTCA and 10:2 FTUCA were accumulated in greater quantities as compared to the 8:2 FTCA and 8:2 FTUCA.

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	C10-2 FTOH
Experiment	-1.52	-0.56	-	-
LSER	-1.51	-0.72	0.04	0.84
COSMOTherm	-1.37	-0.73	-0.31	0.65
SPARC	-1.88	-1.47	-0.83	0.01
HENRYWIN I	-0.65	0.79	2.23	3.67
HENRYWIN II	-0.17	1.83	3.83	5.83

 

Comparison of the experimental 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.