Potassium trifluoroacetate

Endpoint summary

Description of key information

Potassium trifluoroacetate did not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay. 

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 05 oct 2011 to 30 dec 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study, OECD 429 compliant

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

19 july 2011

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Janvier, Le Genest-Saint-Isle, France.
- Age at study initiation: animals of the preliminary test were approximately 10 weeks old and the animals of the main test were approximately 8 weeks old.
- Weight at study initiation: mean body weight of 21.6 g (range: 19.8 g to 23.8 g).
- Housing: The animals were housed by group of two (preliminary test) or four (main test) in polycarbonate cages (Techniplast 1145T, 435 cm2, 36.9 x 15.6 x 13.2 cm) containing autoclaved sawdust (SICSA, Alfortville, France).
Each cage contained two enrichments (mouse hut and cocoon) with possibility of rotation during the study.
In the main test, on day 6 before the 3H-TdR injections, the animals were individually housed in disposable crystal polystyrene cages (22.0 cm x 8.5 cm x 8.0 cm).
- Diet (e.g. ad libitum): All animals had free access to SSNIFF R/M-H pelleted maintenance diet, batch Nos. 9615507 and 7055973, (SSNIFF Spezialdiäten GmbH, Soest, Germany)
- Water (e.g. ad libitum): All animals had free access to tap water (filtered using a 0.22 micron filter) contained in bottles.
- Acclimation period: the animals were acclimated to the study conditions 8 (preliminary test) or 13 (main test) days before the beginning of the treatment period. At the end of acclimation period, the required number of animals was selected according to clinical condition and body weight.

ENVIRONMENTAL CONDITIONS
Temperature: 22 ± 2°C,
Relative humidity: 50 ± 20%,
Light/dark cycle: 12 h/12 h (7:00 - 19:00),
Ventilation: approximately 12 cycles/hour of filtered, non-recycled air.

IN-LIFE DATES: From: 02 nov 2011 To: 14 nov 2011

Vehicle:

dimethylformamide

Concentration:

0, 2.5, 5, 10, 25 and 50%

No. of animals per dose:

4 females per dose

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: As unsatisfactory solubility of the test item was obtained in AOO (i.e. heterogeneous preparation to the naked eye at the concentration of 50% was obtained), dimethylformamide (DMF), batch No. SZBA1190, supplied by Sigma, was used.
A solution was obtained at the concentration of 50% in DMF.
- Irritation: No local reactions were noted in any animals.
No notable increase in ear thickness was observed in any group.
The highest concentration retained for the main test was therefore 50%.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: pooled method
- Criteria used to consider a positive response: The test item is considered as a skin sensitizer when the SI for a dose group is >= 3 together with consideration of a dose-response relationship. Other relevant criteria such as radioactivity levels and ear thickness are also taken into account to evaluate the data.

TREATMENT PREPARATION AND ADMINISTRATION:
Application:
On days 1, 2 and 3, a dose-volume of 25 µL of the control or dosage form preparations was applied to the dorsal surface of both ears, using an adjustable pipette fitted with a plastic tip.
In order to avoid licking and to ensure an optimized application of the test materials, the animals were placed under light isoflurane anesthesia during the administration.
No massage was performed but the tip was used to spread the preparation over the application site. No rinsing was performed.

AURICULAR LYMPH NODE CELL (ALNC) PROLIFERATION ASSAY
Intravenous injection of 3H-TdR and sampling of auricular lymph nodes:
Lymph node cell proliferative response was measured as described by Kimber and Dearman (1). On day 6 of the main test, all animals of all groups received a single intravenous injection of 250 µL of 0.9% NaCl containing 20 µCi of 3H-TdR (specific activity of 20 Ci/mmol) via the tail vein.
Approximately 5 hours later, the main test animals were sacrificed by an intraperitoneal injection of pentobarbital sodium followed by a cervical dislocation and the auricular lymph nodes were excised. The lymph nodes were pooled for each experimental group. A single cell suspension of ALNC was prepared by mechanical disaggregation in Petri dishes with the plunger of a syringe.

Preparation of auricular lymph node cell suspensions and determination of proliferation:
Cell suspensions were washed once with 15 mL of 0.9% NaCl. Each cell suspension was then centrifuged and pellets were precipitated with 3 mL of 5% (w/v) trichloroacetic (TCA) at +4°C overnight. After a last centrifugation, the pellets were precipitated with 1 mL of 5% TCA. Three millilitres of Ultima GoldxR scintillation fluid (Packard) were added in order to measure incorporation of 3H-TdR using beta-scintillation counting.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Positive control results:

The threshold positive value of 3 for the SI was exceeded in the positive control group (SI = 12.16). The experiment was therefore considered valid.

Parameter:

SI

Value:

2.46

Test group / Remarks:

Test item 2.5%

Remarks on result:

other:

Parameter:

SI

Value:

1.72

Test group / Remarks:

Test item 5%

Parameter:

SI

Value:

2.61

Test group / Remarks:

Test item 10%

Parameter:

SI

Value:

0.57

Test group / Remarks:

Test item 25%

Parameter:

SI

Value:

2.05

Test group / Remarks:

Test item 50%

Parameter:

other: disintegrations per minute (DPM)

Value:

391.5

Test group / Remarks:

Test item 2.5%

Parameter:

other: disintegrations per minute (DPM)

Value:

272.88

Test group / Remarks:

Test item 5%

Parameter:

other: disintegrations per minute (DPM)

Value:

415

Test group / Remarks:

Test item 10%

Parameter:

other: disintegrations per minute (DPM)

Value:

90.38

Test group / Remarks:

Test item 25%

Parameter:

other: disintegrations per minute (DPM)

Value:

325.13

Test group / Remarks:

Test item 50%

The acceptance criterion was met; this experiment was therefore considered valid.

The results are presented in the following table:

 

Treatment	Concentration (%)	Irritation level	Stimulation Index (SI)
Test item	2.5	non-irritant	2.46
Test item	5	non-irritant	1.72
Test item	10	non-irritant	2.61
Test item	25	non-irritant	0.57
Test item	50	slightly irritant	2.05
HCA	25	-	12.16

 

No notable lymphoproliferation was noted with the test item at any tested concentrations.

Interpretation of results:

GHS criteria not met

Conclusions:

Potassium trifluoroacetate, did not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay.

Executive summary:

The objective of the study was to evaluate the potential of the test item, Potassium trifluoroacetate, to induce delayed contact hypersensitivity using the murine Local Lymph Node Assay (LLNA). Evaluation of local irritation was also carried out in parallel.

Two groups of two female mice received the test item, Potassium trifluoroacetate, by topical route to the dorsal surface of both ears (one concentration per ear) on days 1, 2 and 3 at concentrations of 5, 10, 25 or 50 % under a dose-volume of 25 µL. From day 1 to day 3 then on day 6, the thickness of both ears of each animal was measured and the local reactions were recorded. Each animal was observed at least once a day for mortality and clinical signs. Body weight was recorded once during the acclimation period, and then on days 1 and 6. On completion of the observation period, the animals were sacrificed then discarded without macroscopic post-mortem examination.

In the main test, five groups of four female mice received the test item by topical route to the dorsal surface of both ears on days 1, 2 and 3 at concentrations of 2.5, 5, 10, 25 or 50% under a dose‑volume of 25 µL. One negative control group of four females received the vehicle (dimethylformamide) under the same experimental conditions. Additionally, one positive control group of four females received the positive control, α‑hexylcinnamaldehyde (HCA), at 25% in a mixture acetone/olive oil (4/1; v/v) under the same experimental conditions.

From day 1 to day 3 then on day 6, the thickness of the left ear of each animal was measured, except in animals of the positive control group, and the local reactions were recorded. Each animal was observed once a day for mortality and clinical signs. Body weight was recorded once during the acclimation period, and then on days 1 and 6.

After 2 days of resting, on day 6, the animals received a single intravenous injection of tritiated methyl thymidine (³H-TdR). Approximately 5 hours later, the animals were sacrificed and the auricular lymph nodes were excised. The proliferation of lymphocytes in the lymph node draining the application site was measured by incorporation of ³H-TdR. The results were expressed as disintegrations per minute (dpm) per group and as dpm/node. The obtained values were used to calculate Stimulation Indices (SI).

No deaths related to the treatment with the test item and no clinical signs were observed during the observation period.

In the main test, dryness of ear skin was noted in all females treated at 10% on day 6. An increase in ear thickness of 14.43% was observed in females treated at 50%. The threshold positive value of 3 for the SI was exceeded in the positive control group (SI = 12.16). The experiment was therefore considered valid. To assess the irritant potential of the test item (through ear thickness measurement), a preliminary test was first performed in order to define the test item concentrations to be used in the main test. No relevant increase in ear thickness was observed in the other test item-treated groups.

Under the experimental conditions of this study, the test item, Potassium trifluoroacetate, did not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a study (2011), the potential of the test item Potassium trifluoroacetate, to induce delayed contact hypersensitivity using the murine Local Lymph Node Assay (LLNA) was evaluated. Mice received the test item at concentrations of 0, 2.5, 5, 10, 25 or 50%. DMF was used as vehicle. 

Under the experimental conditions of this study, Potassium trifluoroacetate did not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

As Potassium trifluoroacetate did not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay, no classification is required according to the directive 67/548/EC and the CLP 1272/2008 regulation criteria.