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Description of key information

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:
2007
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study is non-GLP and similar to OECD TG 426. It well documented, meets generally accepted scientific principles and is therefore acceptable for assessment
Qualifier:
equivalent or similar to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Version / remarks:
Method: Popliteal lymph node assay (PLNA)
Principles of method if other than guideline:
Method: Popliteal lymph node assay (PLNA)
GLP compliance:
not specified
Type of study:
other: Popliteal lymph node assay (PLNA)
Species:
other: rat
Strain:
other: Wistar
Sex:
female

Table 1: Primary PLNA responses

 

 Criteria

Negative controls

Vehicle

Chlorpromazine

 

 Terpineol 

 Barbital 

DMSO

 Saline

0.5 mg/paw

2.5 mg/paw

5.0 mg/paw

 N 

 10 

 8 

 47 

 50 

 4 

 6 

 11 

 WI 

 1.32 ± 0.71 

 1.06 ± 0.36 

 1.48 ± 0.65 

 1.12 ± 0.90 

 1.30 ± 0.35 

 2.06 ± 0.81* 

 3.22 ± 1.13* 

 CI 

 2.00 ± 3.32 

 1.34 ± 0.92 

 2.95 ± 3.68 

 2.04 ± 2.03 

 1.26 ± 0.81 

 8.49 ± 8.91* 

 8.28 ± 8.19* 

 IPR, no. (%) 

 2 (20) 

 0 (0) 

 5 (10.6) 

 3 (6) 

 0.0 

 50.0 

 63.6* 

* indicates that the value differs from that of the lowest dose group (0.5 mg/paw)

- Injected doses were 5 mg/paw (monoterpenes and barbital) or 50 µL /paw (vehicles).

- Values are means ± SD;

- Weight (WI) and Cellularity (CI) indices: values for the draining popliteal lymph node of the treated (right paw) side divided by that of the control (left paw) side.

- IPR, number (%) of rats within the group with WI 2 and CI 5.

- Substances were classified as negative because group mean values for WI and CI were lower than 2 and 5, respectively.

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under these test conditions, alpha-terpineol was not considered as a sensitiser.
Executive summary:

In a popliteal lymph node assay (PLNA), a group of 10 female Wistar rats were injected subcutaneously with alpha-Terpineol at 5 mg/paw into the right hind footpad while the contralateral footpad was injected with the vehicle (DMSO) alone. Chlorpromazine (CPZ) and barbital were used as positive and negative controls, respectively. Weight (WI) and cellularity (CI) indices for draining PLNs were determined 7 days after treatment. 

Weight (WI) and cellularity (CI) indices for alpha-Terpineol was determined to be 1.32 ± 0.71 and 2.00 ± 3.32, respectively. Alpha-terpineol was classified as negative because group mean values for WI and CI were lower than 2 and 5, respectively.

Under these test conditions, alpha-terpineol was not considered as a sensitiser.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:
Migrated from Short description of key information:
In a popliteal lymph node assay (PLNA), a group of 10 female Wistar rats were injected subcutaneously with alpha-Terpineol at 5 mg/paw into the right hind footpad while the contralateral footpad was injected with the vehicle (DMSO) alone (Friedrich 2007). Chlorpromazine (CPZ) and barbital were used as positive and negative controls, respectively. Weight (WI) and cellularity (CI) indices for draining PLNs were determined 7 days after treatment. Weight (WI) and cellularity (CI) indices for alpha-Terpineol was determined to be 1.32 ± 0.71 and 2.00 ± 3.32, respectively. Alpha-Terpineol was classified as negative because group mean values for WI and CI were lower than 2 and 5, respectively. Under these test conditions, alpha-Terpineol was not considered to be a skin sensitiser.

Justification for selection of skin sensitisation endpoint:
The one skin sensitisation study with alpha-Terpineol is sufficiently adequate for this assessment of this end point.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:
Migrated from Short description of key information:
Since alpha-Terpineol is not a skin sensitiser, it is unlikely that it is a respiratory sensitiser as can be derived when following the ITS scheme in the REACH guidance: Scheme of R7A, Fig. 7.3 -2.

Justification for selection of respiratory sensitisation endpoint:
Alpha-Terpineol is not considered a respiratory sensitiser because it is not a skin sensitiser.

Justification for classification or non-classification

Alpha-Terpineol is negative in the skin sensitisation study and therefore classification of alpha-Terpineol for skin and respiratory sensitisation is not warranted according to EU Directive 67/548 and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.