Gum turpentine oil, consisting of the volatile fraction resulting from the distillation of oleoresin collected by tapping softwoods from pinacea derivatives (genus: pinus). It consists of terpenes, mainly monoterpenes such as alpha-pinene and beta-pinene.

Endpoint summary

Description of key information

In a recent GLP LLNA study using beta pinene, stimulation index was higher than 3 at 50 and 100% and EC3 value was determined to be 29%.

In maximisation tests on guinea pigs using turpentine oil, 16/25 animals showed positive responses, respectively.

In a clinical trial, turpentine oil was identified as a strong sensitiser, with 16/25 human volunteers showing positive response to turpentine oil.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1969

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Well performed study following the method similar to OECD guideline 406 with minor deviations: no data on housing conditions and individual weight of animals; no data on nature and degree of effects observed

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

no data on housing conditions and individual weight of animals; no data on nature and degree of effects observed

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A study on skin sensitisation conducted with the registered substance (OECD 406) is available.

Species:

guinea pig

Strain:

other: albino

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 300-500 g

Route:

intradermal and epicutaneous

Vehicle:

petrolatum

Concentration / amount:

- Induction: 5% (Intradermal) and 25% by weight (topical)
- Challenge: 20% by weight

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

- Induction: 5% (Intradermal) and 25% by weight (topical)
- Challenge: 20% by weight

No. of animals per dose:

10 female

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- Exposure period: One week (first stage); 48 hours (second stage)
- Site: Shoulder
- Concentrations: 5% and 25% by weight (intradermal and topical, respectively)

B. CHALLENGE EXPOSURE
- Site: Flank
- Concentrations: 20% by weight
- Evaluation (hr after challenge): 24

C. Maximization grading:
Sensitization rate: 0-8% - grade I- Weak; 9-28% - grade II- Mild; 29-64% - grade III- moderate; 65-80% - grade IV- strong; 81-100%- grade V- extreme

Challenge controls:

The animals were challenged two weeks after the topical induction by applying 20% by weight of turpentine oil in petrolatum to the flank for 24 hours under a 4 cm strip of Blenderm.

Positive control substance(s):

not specified

Positive control results:

No data

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

20% by weight

No. with + reactions:

16

Total no. in group:

25

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 20% by weight. No with. + reactions: 16.0. Total no. in groups: 25.0.

Group:

positive control

Remarks on result:

other: no data available

Group:

negative control

Remarks on result:

other: no data available

None

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Remarks:

Migrated information

Conclusions:

Turpentine oil is considered to be as skin sensitizer.

Executive summary:

In a skin sensitization study performed following the method similar to OECD guideline 406, sensitization potential of turpentine oil was assessed by guinea pig maximization test. Group of female albino guinea pigs were induced with 5% (intradermal injection) and 25% (topical) by weight of turpentine oil, followed by a challenge dose of 20% by weight of turpentine oil in petrolatum to the flank on clipped skin using an occlusive patch held in place for 24 hours. The challenge site was evaluated 24 hours after removal of the patch.

16 out of 25 animals tested showed the signs of sensitization during the study period which corresponds to 64% of sensitization rate.

Therefore, turpentine oil is considered as a skin sensitizer.

Reference 2

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was performed according to the OECD guideline 429 and in compliance with GLP without any deviations.

Justification for type of information:

Beta-Pinene is a main constituent of UVCB substance gum tupentine oil. Therefore, data on beta-pinene can be used for extrapolation to gum turpentine oil. See read-across justification document in section 13.

Reason / purpose for cross-reference:

read-across source

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Positive control results:

In the positive control group given HCA at the concentration of 25%, the mean cell viability in the vehicle group was higher than 70% and the threshold positive value of 3 for the SI was reached in the positive control group (see table 3). The study was therefore considered valid.

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

A dryness of the skin was noted in all animal treated at the concentration of 100% (group 6), associated with an erythema in one of them. The increase in ear thickness measured in group 6 was 21.36%, corresponding to a slightly irritant potential of the test item when used in its original form. A significant lymphoproliferation was noted at tested concentrations of 50% and 100%: the stimulation index was higher than 3 at these two concentrations. In the absence of excessive local irritation, the significant lymphoproliferative responses observed were attributed to delayed contact hypersensitivity. The EC3 value for the test item Beta pinene is equal to 29% (see table 7.4.1/3).

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: See details in Table 3.

Neither mortality nor clinical signs were observed during the study. The body weight gain of the treated animals was similar to that of the control animals.

Table 3: Study results

Groups	Treatment and concentrations	Cell count		Viability (%)	Amount of cells (x10^6cells)	Cellularity index	Number of nodes per group	dpm per group	dpm per node	Stimulation index (SI)	Increase in ear thickness (% between day1 and day 6)	Irritation level	EC3value
		viable	dead
1	Vehicle	88	16	84.62	8.80	-	8	1286.00	160.75	-	-3.88	-	-
2	Test item 5%	190	18	91.35	19.00	2.16	8	2947.00	368.38	2.29	-1.01	I	29%
3	Test item 10%	48	39	55.17	4.80	0.55	8	1487.00	185.88	1.16	-0.98	I
4	Test item 25%	143	23	86.14	14.30	1.63	8	2869.00	358.63	2.23	-2.02	I
5	Test item 50%	270	40	87.10	27.00	3.07	8	9218.00	1152.25	7.17	-2.83	I
6	Test item 100%	219	41	84.23	21.90	2.49	8	8318.00	1039.75	6.47	21.36	II
7	HCA 25%	622	44	93.39	62.20	7.07	8	18223.00	2277.88	14.17	-	-	-

Viability= (viable cells/(viable cells+dead cells))*100

Cellularity index=amount of cells (x10⁶cells) in the treated groups/ amount of cells (x10⁶cells) in the vehicle groups

Stimulation index=dpm of treated group/dpm of control group

Vehicle: acetone/olive oil

Test item:Beta pinene

dpm: disintegration per minute

HCA:α-hexylcinnamaldehyde

I: non-irritant (increase in ear thickness < 10%)

II: slightly irritant (increase in ear thickness = 10 to 30%)

EC3 value: Theoretical concentration resulting in a SI value of 3

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Remarks:

Migrated information

Conclusions:

The test item induced delayed contact hypersensitivity in the murine Local Lymph Node Assay.
Therefore, beta-pinene is classified as skin sensitizer category 1B according to CLP regulation (EC) No 1272/2008 and as skin sensitizer "Xi, R43: May cause sensitisation by skin contact" according to Directive 67/548/EEC.

Executive summary:

In a dermal sensitization study performed according to OECD guideline 429 and in compliance with the GLP, beta-pinene in Acetone/Olive oil (4/1, v/v) was administered to CBA/J mice. In the preliminary assay, at the highest tested concentration (100%) only, dryness of the skin was observed in one animal. The highest increase in ear thickness (15.38%), observed in one animal treated at the concentration of 100%, was attributed to a slight irritation. Since the test item was not excessively irritant in the preliminary test, the highest concentration retained for the main test was the maximal practicable concentration (100%).

Five treated groups of four animals receiving applications of 0.25 µL of the test item to the external surface of botch ears at the concentration of 5, 10, 25, 50 or 100% in the vehicle. The Lymph node proliferative responses were measured as described by Kimber and Dearman (1991).

The positive control (α-hexylcinnamaldehyde) gave acceptable positive results (stimulation index of 14.17).

No clinical signs and no mortality were observed during the study. A dryness of the skin was noted in all animal treated at the concentration of 100%, associated with an erythema in one of them. The increase in ear thickness measured in the 100% group was 21.36%, corresponding to a slightly irritant potential of the test item when used in its original form. A significant lymphoproliferation was noted at tested concentrations of 50% and 100%: the stimulation index was higher than 3 at these two concentrations. In the absence of excessive local irritation, the significant lymphoproliferative responses observed were attributed to delayed contact hypersensitivity. The EC3 value was 29%.

Under the experimental conditions of this study, beta-pinene induced delayed contact hypersensitivity in the murine Local Lymph Node Assay.

Therefore, beta-pinene is classified as skin sensitizer category 1B according to CLP regulation (EC) No 1272/2008 and as skin sensitizer "Xi, R43: May cause sensitisation by skin contact" according to Directive 67/548/EEC.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In a recent GLP LLNA study using beta pinene, stimulation index was higher than 3 at 50 and 100% and EC3 value was determined to be 29%.

In maximisation tests on guinea pigs using turpentine oil, 16/25 animals showed positive responses, respectively.

In a clinical trial, turpentine oil was identified as a strong sensitiser, with 16/25 human volunteers showing positive response to turpentine oil.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

As beta pinene and turpentine oil show clear signs of skin sensitisation, therefore gum turpentine oil is classified as skin sensitiser category 1B (H317: May cause an allergic skin reaction) according to CLP regulation (EC) n° 1272/2008 and as skin sensitiser (Xi, R43: May cause sensitisation by skin contact) according to Directive 67/548/EC.