p-anisic acid

Endpoint summary

Description of key information

skin irritation (no guideline followed): not irritating

eye irritation (no guideline followed): not irritating

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

- The test was conducted before guideline was adopted.

- Principle of test: the test substance was applied to one auricle (inner surface) of each of 2 rabbits under semi-occlusive conditions for 24 hours. After the exposition remaining test item was removed by washing. Observations were made at removal of test item, after 24, 48 and 72 h as well as 7 days after application

- Parameters analysed / observed: erythema, edema and eschar formation

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 3-4 kg
- Housing: single housing
- Diet: typal feeding, ad libitum
- Water: ad libitum

Type of coverage:

semiocclusive

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Remarks:

; the test item was moistened with water before application

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 500 mg

Duration of treatment / exposure:

24 h

Observation period:

7 days
Reading time points: after washing, 24, 48 and 72 h and 7 days

Number of animals:

2

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: with water and soap
- Time after start of exposure: 24 h

OBSERVATION TIME POINTS
- after washing, 24, 48 and 72 h and 7 days

SCORING SYSTEM:
- the scoring system used for interpretation of the skin reaction was not specified

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: not applicable

Irritation parameter:

other: eschar formation

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: not applicable

Irritant / corrosive response data:

At none of the reading time points, reactions indicative of skin irritation were noticed.

Other effects:

- Adverse systemic effects: no systemic effects were reported.

Interpretation of results:

GHS criteria not met

Conclusions:

In a reliable study, that was conducted prior to implementation of the current guidelines, the skin irritation potential of p-anisic acid was tested by semiocclusive application of the test substance to rabbit ears for 24 h. No skin reaction was noted at any reading time point thus under the conditions of the test the compound was not a skin irritant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

- The test was conducted before guideline was adopted

- Principle of test: the test substance was applied to the left conjunctical sacs of two rabbits, observations were made 1, 24, 48, 72, 96 h as well as 7 days after application

- Parameters analysed / observed: conjunctival chemosis, reddening and swelling, corneal opacity, iritis

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 3-4 kg
- Housing: single housing
- Diet: typal feeding, ad libitum
- Water: ad libitum

Vehicle:

unchanged (no vehicle)

Remarks:

; the test item was moistened with water before application

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 50 mg

Duration of treatment / exposure:

not applicable as it is not specified whether the treated eyes were rinsed or not

Observation period (in vivo):

7 days
Reading time points: 1, 24, 48, 72 and 96 h and 7 days

Number of animals or in vitro replicates:

2

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: not stated

SCORING SYSTEM:
- scoring was done but the scoring system used for interpretation of the eye reaction was not specified

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: not applicable

Irritation parameter:

iris score

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: not applicable

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0.3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of 2 animals

Time point:

24/48/72 h

Score:

0

Reversibility:

other: not applicable

Irritant / corrosive response data:

A grade 1 conjunctivae redness was noted 1 h after instillation in both animals. At the 24 h reading time point, the conjunctivae redness graded 1 was still present in one animal, whereas in the second, the finding seems to become weaker, as based on the grading reported as (1). After 48 hours, no more conjunctivae redness was seen for both animals, indicating complete reversibility. No further effects were noticed.

Table 1: In Vivo Eye Irritation Scores

Animal No.	Irritation parameter	Reading times
		1h	24 h	48 h	72 h	96 h	7 days
21	cornea	0	0	0	0	0	0
	iris	0	0	0	0	0	0
	conjunctiva	1	1	0	0	0	0
	chemosis	0	0	0	0	0	0
	lacrimation	0	0	0	0	0	0
22	cornea	0	0	0	0	0	0
	iris	0	0	0	0	0	0
	conjunctiva	1	(1)	0	0	0	0
	chemosis	1	0	0	0	0	0
	lacrimation	0	0	0	0	0	0

 

Interpretation of results:

GHS criteria not met

Conclusions:

In a reliable study, that was conducted prior to implementation of the current guidelines, the eye irritation potential of p-anisic acid was tested in two rabbits. Eye reactions were restricted to conjunctivae redness which disappeared within 48 h. It was concluded that under the test conditions used, p-anisic acid was slightly and transiently irritant to the eye, but the obtained results do not warrant any classification as irritant to the eye.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

The skin irritation potential of the test substance was determined by a primary skin irritation/corrosion study in the rabbit.

In this study 500 mg test substance moistened with water were applied to the inner auricle surface of 2 New Zealand White rabbits under semi-occlusive conditions for 24 h (Thyssen, 1979). Scoring of skin reactions (erythema, edema and eschar formation) was performed immediately, 24, 48 and 72 hours as well as 7 days after removal of the patch. Exposure to the test substance did not result in any signs of irritation at any reading point. The overall mean irritation scores over 24, 48 and 72 h for erythema and edema were 0. No mortality occurred. Based on the results, the test item was not irritating to the skin in the in vivo primary skin/corrosion study in rabbits under the experimental conditions used.

 

Eye

The eye irritation potential of the test substance was determined in three studies. An acute eye irritation study in the rabbit, a bovine corneal opacity and permeability test (BCOP test) and a HET-CAM study were conducted.

In an acute eye irritation study samples of 50 mg test substance (moistened with water) were instilled into one eye of each of 2 New Zealand White rabbits (Thyssen, 1979). Eye reactions were scored 1, 24, 48, 72 and 96 hours as well as 7 days after instillation. Instillation of the test substance resulted in effects on the conjunctivae. The irritation of the conjunctivae consisted of grade 1 redness noted at 1 and 24 hours and completely resolved within 48 hours in both animals. A grade 1 chemosis was noted in 1 animal 1 h after instillation and was fully reversible within 24 hours. The overall mean irritation scores over 24, 48 and 72 h for conjunctival redness, chemosis, iris and corneal effects were 0.33, 0, 0 and 0, respectively. No mortality occurred. Based on the results, the test substance was not irritating to the eyes under the conditions of the test.

A supporting BCOP test with the test substance is available and was performed according to OECD Guideline 437 and in compliance with GLP (Paulus, 2009). The non-surfactant solid test substance was applied as a solid to the epithelial surface of three cattle corneas for 4 hours at 32 °C. The applied amounts were ranging from 203 to 294 mg. After exposure the corneas were washed and the damage by the test substance was assessed directly by quantitative measurement of changes in corneal opacity with an opacitometer. In addition the permeability of the corneas was measured with an ultraviolet/visible spectrophotometer after incubation of the corneas with sodium fluorescein solution for 90 min. The results of the opacity and permeability measurement were used to calculate an in vitro irritation score (IVIS) of 3.274. The negative control responses for opacity and permeability were less than the upper limits of the laboratory historical range indicating that the negative control (physiol. saline) did not induce irritancy on the corneas. The mean in vitro irritation score of the positive control (20% (w/v) imidazole) was 62.4670 and within the historical positive control data range. It was therefore concluded that the test conditions were adequate and that the test system functioned properly. Since p-anisic acid induced an IVIS of > 3 ≤ 55, no prediction on the classification could be made based on this test, except for the prediction that the test substance is not expected to cause severe damage to the eye.

In a supporting HET CAM study that was performed according to the ICCVAM recommended test method protocol, dated November 2006 and in compliance with GLP (Paulus, 2010) the irritation potential of the test item was assessed by detection of damages in blood vessels under the chorioallantoic membrane (CAM) of nine day incubated chicken eggs. Nine day incubated chicken eggs were opened on the air bubble with a rotating dentist's saw blade. The inner membrane was moistened with 0.9% NaCl and the egg was placed in an incubator for 30 min. After this incubation the solution was decanted and the inner membrane was carefully removed with forceps. The test item (approximately 110 mg) was directly applied to the CAM surface so that 50% of the membrane were covered. The following parameters were observed: haemorrhage from the vessels, vascular lysis, coagulation (intra- and extravascular protein denaturation). The reactions of the CAM were observed over a period of 300 sec. The time for the appearance of each endpoint was monitored and recorded in seconds and a resulting irritation score (IS) was calculated. Physiological saline served as the negative control while 0.1 N sodium hydroxide (NaOH) and 1% sodium dodecyl sulphate (SDS) served as positive controls. Five replicates were used for the test item and three each for the positive and negative controls.

Application of the test item did not result in damage to the vessels of the CAM and the resulting IS was 0.0. Also the negative control induced no irritating effect (mean IS = 0.0), while both positive controls induced severe damage to the CAM blood vessels (mean IS for NaOH and SDS was 20.5 and 11.32, respectively). Thus, the results of this study gave no indication of a damaging effect of the test item to be expected for the eye.

Justification for classification or non-classification

The available data on skin and eye irritation of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 and are therefore conclusive but not sufficient for classification.