Reaction mass of 2,2',2''-nitrilotriethanol and disodium succinate and sodium acetate and sodium bromide

Endpoint summary

Description of key information

In a valid, reliable and conclusive study under GLP and according to OECD TG 429 and EU Method B42, the test item Reaction Mass of CXN1-55 was considered to be a non-sensitizer under the conditions of the test.

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:

2013-02-05 to 2013-04-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study according to OECD TG 429 (2010) and EU Method B42 (2008) and under GLP

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

other: CBA/Ca (CBA/CaOlaHsd)

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS- Source: Harlan Laboratories UK Ltd., Oxon, UK- Age at study initiation: eight to twelve weeks- Weight at study initiation: weight range of 15 to 23 g- Housing: The animals were individually housed in suspended solid floor polypropylene cages furnished with softwood woodflakes.- Diet: Free access to food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK)- Water): Free access to mains tap water- Acclimation period: at least five daysENVIRONMENTAL CONDITIONS- Temperature (°C): 19 to 25 °C- Humidity (%): 30 to 70 %,- Air changes (per hr): approximately fifteen changes per hour- Photoperiod (hrs dark / hrs light): 12 hours / 12 hoursIN-LIFE DATES: From: 2013-02-05 To: 2013-02-20

Vehicle:

other: ethanol/distilled water 7:3

Concentration:

concentrations of 25 %, 10 % or 5 % w/w

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:Using available information regarding the systemic toxicity potential of the test item, a preliminary screening test was performed using one mouse. The mouse was treated by daily application of 25 μL of the test item at a concentration of 25 % w/w in ethanol/distilled water 7:3, to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The mouse was observed twice daily on Days 1, 2 and 3 and once daily on Days 4, 5 and 6. Local skin irritation was scored daily. Any clinical signs of toxicity, if present, were also recorded. The bodyweight was recorded on Day 1 (prior to dosing) and on Day 6.- Compound solubility:8 different vehicles tested at 50 % test item concentration (0.5 g test item + 0.5 g vehicle): not suitable for dosing8 different vehicles tested at 25 % test item concentration (1 g of 50 % dilution made up to 2 g): suspension in ethanol/destilled water (7:3), suitable for dosing- Irritation: No signs of systemic toxicity, visual local skin irritation or irritation indicated by an equal to or greater than 25 % increase in mean ear thickness were noted. Based on this information the dose levels selected for the main test were 25 %, 10 % or 5 % w/w in ethanol/distilled water 7:3.- Lymph node proliferation response: only conducted in the main testMAIN STUDYANIMAL ASSIGNMENT AND TREATMENT- Name of test method: Estimation of the Proliferative Response of Lymph Node Cells- Criteria used to consider a positive response: the proliferation response of lymph node cells was expressed as the number of radioactive disintegrations per minute per lymph node (disintegrations per minute/node) and as the ratio of 3HTdR incorporation into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index). The test item will be regarded as a sensitiser if at least one concentration of the test item results in a threefold or greater increase in 3HTdR incorporation compared to control values. Any test item failing to produce a threefold or greater increase in 3HTdR incorporation will be classified as a "non sensitiser."TREATMENT PREPARATION AND ADMINISTRATION:Test Item AdministrationGroups of four mice were treated with the test item at concentrations of 25 %, 10 % or 5 % w/w in ethanol/distilled water 7:3. The preliminary screening test suggested that the test item would not produce systemic toxicity or excessive local skin irritation at the highest suitable concentration. The mice were treated by daily application of 25 μL of the appropriate concentration of the test item to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The test item formulation was administered using an automatic micropipette and spread over the dorsal surface of the ear using the tip of the pipette. A further group of four mice received the vehicle alone in the same manner.3H-Methyl Thymidine AdministrationFive days following the first topical application of the test item or vehicle (Day 6) all mice were injected via the tail vein with 250 μL of phosphate buffered saline (PBS) containing 3H methyl thymidine (3HTdR: 80 μCi/mL, specific activity 2.0 Ci/mmoL, ARC UK Ltd) giving a total of 20 μCi to each mouse.

Positive control substance(s):

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

Statistics:

not applicable

Positive control results:

The sensitivity of the strain of mouse used is tested twice a year. The last test (January 2013) with the positive control α-Hexylcinnamaldehyde, tech., 85 %, at a concentration of 15 % in EtoH/H20 (70:30) resulted to an SI of 18.54.

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

Concentration (% w/w) in ethanol/distilled water 7:3: 5, Stimulation Index: 0.78, Result: NegativeConcentration (% w/w) in ethanol/distilled water 7:3: 10, Stimulation Index: 0.94, Result: NegativeConcentration (% w/w) in ethanol/distilled water 7:3: 25, Stimulation Index: 1.47, Result: Negative

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

Vehicle, dpm 8151.53, dpm/node: 1018.94Concentration (% w/w) in ethanol/distilled water 7:3: 5, dpm 6368.01, dpm/node: 796.00Concentration (% w/w) in ethanol/distilled water 7:3: 10, dpm 7671.70, dpm/node: 958.96Concentration (% w/w) in ethanol/distilled water 7:3: 25, dpm: 12002.35, dpm/node: 1500.29

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In a valid, reliable and conclusive study under GLP and according to OECD TG 429 and EU Method B42, the test item Reaction Mass of CXN1-55 was considered to be a non-sensitizer under the conditions of the test.

Executive summary:

In a valid, reliable and conclusive study under GLP, the skin sensitisation potential of the test item Reaction Mass of CXN1-55 was assessed in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear, according to OECD TG 429 and Method B42 (EU).

Following a preliminary screening test in which no clinical signs of toxicity were noted at a concentration of 25 % w/w, this concentration was selected as the highest dose investigated in the main test of the Local Lymph Node Assay. Three groups, each of four animals, were treated with 50 μL (25 μL per ear) of the test item as a suspension in ethanol/distilled water 7:3 at concentrations of 25 %, 10 % or 5 % w/w. A further group of four animals was treated with ethanol/distilled water 7:3 alone.

The Stimulation Index expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group are as follows:

Concentration 5 % w/w): stimulation Index 0.78 (negative)

Concentration 10 % (w/w): stimulation index 0.94 (negative)

Concentration 25 % (w/w): stimulation index 1.47 (negative)

Conclusion: The test item was considered to be a non-sensitizer under the conditions of the test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a valid, reliable and conclusive study under GLP, the skin sensitisation potential of the test item Reaction Mass of CXN1-55 was assessed in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear, according to OECD TG 429 and Method B42 (EU).
The test item was considered to be a non-sensitizer under the conditions of the test.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

According to ECHA Endpoint Specific Guidance R.7a (Nov-2012, page 235 & 241), there is evidence that chemical respiratory allergens will also elicit positive responses in the LLNA, although this assay does not represent a method for the specific identification of chemical respiratory allergens. The interpretation is therefore that a chemical which fails to induce a positive response in the LLNA (at an appropriate test concentration) most probably lacks the potential for respiratory allergy. Therefore, the test of respiratory sensitisation can be waived, and a test on respiratory sensitisation does not need to be conducted.

Justification for classification or non-classification

Based on the current data, CNX1 -55 is not classified for sensitizing properties according to Regulation (EC) No. 1272/2008 on Classification, Labelling and Packaging of Substances and Mixtures.