DL-hexane-1,2-diol

Endpoint summary

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 April 23, 2003 to April 29, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline test with GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (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:

CBA

Sex:

female

Details on test animals and environmental conditions:

Test Animals
Mice, CBA/Ca01aHsd, female, age 7-12 weeks, 5 mice per test group
The animals were derived from a controlled full barrier maintained breeding system (SPF).
Source: Harlan Winkelmann GmbH, D-33178 Borchen.
According to Art. 9.2, No.7 of the German Act on Animal Welfare the animals are bred for experimental purposes.
Animal Husbandry
The animals were barrier maintained (semi-barrier) in an air conditioned room
- Temperature: 22 ± 30C -Rel. humidity: 55 ±10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: at least 10 x / hour
- Feeding ad libitum, Altromin 1324 maintenance diet for rats and mice， totally-pathogen-free (TPF)
- Free access to tap water (drinking water, municipal residue control， microbioL controlled periodically)
- The animals were kept in groups in Macrolon - cages on Altromin saw fiber bedding
- Certificates of food, water and bedding are filed at BSL Bio service
- Adequate acclimatisation period

Vehicle:

other: AOO (3+1 (v/v) Acetone/Olive Oil)

Concentration:

at three concentrations of 100 %, 50 % and 10 % (w/w) respectively.

No. of animals per dose:

5

Details on study design:

Preparation of the Animals
The animals were randomly selected.
Identification was ensured by cage number and individual marking (tail).
Test Regime:
Topical Application
Each mouse was treated by topical application of 25 µl of the selected solution to the entire dorsal surface of each ear.
Topical applications were performed once daily over three consecutive days. Administration of 3H-methyl thymidine
Five days after the first topical application treatment all mice were dosed with 20 µCi 3H-methyl thymidine by intravenous injection (tail vein) of 250 µl of 3H-methyl thymidine, diluted to a working concentration of 80 µCi/mL
Preparation of cell suspension
Approximately 5 hours after H-methyl thymidine-injection all mice were sacrificed. The draining "auricular lymph nodes“ were excised, weighed individually pooled for each animal (2 lymph nodes per animal, if technically possible) and collected in PBS. A single cell suspension of pooled lymph node cells was prepared by gentle mechanical disaggregation through polyamid gauze (200 mesh size). After washing the gauze with PBS the cell suspension was pelleted in a centrifuge. The supernatant was discarded and the pellets were resuspended with PBS. This washing procedure was repeated twice.
After the final wash each pellet was resuspended in approx. 3 ml 5% TCA at approx. 4 °C overnight for precipitation of macromolecules. Each precipitate was recovered by centrifugation, resuspended in 1 ml 5% TCA and transfered into scintillation vials.
Determination of incorporated 3H-methyl thymidine
The 3H-methyl thymidine - incorporation was measured in a β-counter and expressed as the number of disintegrations per minute (DPM). Similarly,
background 3H-methyl thymidine levels were also measured (5% TCA). Determination of radioactivity was performed individually for each animal.
If all measured points are above or below the stimulation index of three, no EC3 value can be stated. A substance is regarded as a 'sensitizer' in the LLNA if at least one concentration of the test item results in a 3 fold or greater increase in 3H-methyl thymidine - incorporation into lymph node cells of the lymph nodes of the test group animals, relative to that recorded for the lymph nodes of control group animals (Stimulation Index equal to or greater than 3.0.).

Positive control substance(s):

not specified

Statistics:

A substance is regarded as a 'sensitizer' in the LLNA if at least one concentration of the test item results in a 3 fold or greater increase in 3H-methyl thymidine - incorporation into lymph node cells of the lymph nodes of the test group animals, relative to that recorded for the lymph nodes of control group animals (Stimulation Index equal to or greater than 3.0.).

Positive control results:

no data

Parameter:

SI

Remarks on result:

other: 100%: 0.6 50%: 1.9 10%: 1.6

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: negative control: 29.5 ±1.7; 10%: 33.2 ±8.3; 50%:35.6 ±11.1; 100%: 26.6±8.6

The EC3 value (derived by linear interpolation) could not be stated because all measure points were below three.

All animals survived throughout the test period without showing any clinical signs. Weight gain of all animals was within the expected range.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the data given in this study, the test item caused no sensitization as the stimulation index was below 3.0 for each concentration tested.

Executive summary:

This study was conducted following to OECD guideline 429 and 406 and GLP principles. Each mouse was exposed to the prepared test article at three concentrations of 100%, 50% and 10% (w/w) respectively by topical application to the entire dorsal surface of each ear once daily over three consecutive days. Five days after the first application all mice were injected intravenoulsy with ³H-methyl thymidine. 5 hours after injection all mice were sacrified and the draining were excised and weighted individually. The stimulation index at concentrations of 100%, 50% and 10% is 0.6, 1.9 and 1.6, respectively.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

This study was conducted following to OECD guideline 429 and 406 and GLP principles. Each mouse was exposed the prepared test article at three concentrations of 100%, 50% and 10% (w/w) respectively by topical application to the entire dorsal surface of each ear once daily over three consecutive days. Five days after the first application all mice were injected intravenously with³H-methyl thymidine. 5 hours after injection all mice were sacrificed and the draining were excised and weighted individually. The stimulation index at concentrations of 100%, 50% and 10% is 0.6, 1.9 and 1.6, respectively.

Migrated from Short description of key information:
Test item caused no sensitization as the stimulation index was below 3.0 for each concentration tested.

Justification for selection of skin sensitisation endpoint:
only sensitisation study available

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Non-human information: This information is not available.

Human information: No human information is available

Justification for classification or non-classification

In a guideline-compliant primary skin sensitisation study in mice (LLNA), 1,2-hexandiolshowed no skin sensitising properties. Therefore, 1,2-hexandioldoes not have to be classified as a skin sensitizer according to the criteria laid down in the EU Dangerous Substances Directive (67/548/EEC) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC).

Due to lack of data the substance is also not classified for respiratory sensitisation according to CLP.