1,4-dimethoxybenzene

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 02 mar 2007 to 29 may 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,4-dimethoxybenzene

EC Number:

205-771-9

EC Name:

1,4-dimethoxybenzene

Cas Number:

150-78-7

Molecular formula:

C8H10O2

IUPAC Name:

1,4-dimethoxybenzene

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS:
- Source: Harlan Netherlands BV
Kreuzelweg 53
NL-5961 NM Horst / The Netherlands
Postbus 6174
NL-5960 AD Horst / The Netherlands
- Age at study initiation: 15 weeks (male); 13, 14 weeks (females)
- Weight at study initiation: between 2.6 to 3.2 kg
- Housing: Individually in stainless steel cages equipped with feed hoppers and drinking water bowls. Wood blocks (RCC Ltd, Füllinsdorf) and haysticks 4642 (batch no. 08/07, Provimi Kliba AG) were provided for gnawing.
- Diet: Pelleted standard Provimi Kliba 3418 rabbit maintenance diet ad libitum (batch no. 83/06) provided by Provimi Kliba AG, CH-4303 Kaiseraugst. Results of analysis for contaminants are archived at RCC Ltd.
- Water: Community tap water from Füllinsdorf, ad libitum. Results of bacteriological, chemical and contaminant analyses are archived at RCC Ltd.
- Acclimation period: Under laboratory conditions after health examination. Only animals without any visual signs of illness were used for the study.

ENVIRONMENTAL CONDITIONS:
- Temperature (°C): 17-23°C
- Humidity (%): 30-70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12. Music was played during the daytime light period.

IN-LIFE DATES: From 07 or 08 mar 2007 to 12 mar 2007

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: the other eye served as control

Amount / concentration applied:

- TEST MATERIAL:
Amount applied: 0.1 g
Concentration: pure
pH: 6.84

Observation period (in vivo):

72 hours

Number of animals or in vitro replicates:

3: 1 male and 2 females

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): not rinsed

SCORING SYSTEM: according the Commission Directive 2004/73/EC april 29, 2004

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: no effects

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

0.44

Max. score:

3

Reversibility:

fully reversible within: 72h

Results 4

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.33

Reversibility:

fully reversible within: 48 hours

Results 5

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Reversibility:

fully reversible within: 48 hours

Results 6

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.67

Reversibility:

fully reversible within: 72h

Results 7

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Other effects:

The mean score was calculated across 3 scoring times (24, 48 and 72 hours  after instillation) for each animal for corneal opacity, iris, redness and 
chemosis of the conjunctivae, separately. The individual mean scores  for corneal opacity and iris were 0.00 for all three animals. The  individual 
mean scores for the conjunctivae were 0.33, 0.33 and 0.67 for  reddening, respectively and 0.00 for chemosis for the three animals. No abnormal 
findings were observed in the cornea or iris of any animal at  any of the measurement intervals. A slight to moderate reddening of the conjunctivae 
was noted in all  animals at the 1-hour observation and persisted as slight up to the  24-hour reading in two animals and up to the 48 -hour 
observation in one  animal. Additionally, all animals expressed a slight reddening of the  sclera 1 hour after instillation, which persisted in one female 24 hours later. Slight to moderate discharge was recorded in all three animals at  the 1 -hour reading.

Any other information on results incl. tables

Result table:

 

Score at time point / Reversibility	Cornea	Iris	Conjunctivae	Chemosis
	Max. score: 4	Max. score: 2	Max. score: 3	Max. score: 4
60 min	0/0/0	0/0/0	1/1/2	0/0/0
24 h	0/0/0	0/0/0	1/1/1	0/0/0
48 h	0/0/0	0/0/0	0/0/1	0/0/0
72 h	0/0/0	0/0/0	0/0/0	0/0/0
Average 24h, 48h, 72h	0	0	0.33/0.33/0.67	0
Reversibility*)	No effects	No effects	fully	No effects

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Classification: not irritating

Executive summary:

In a primary eye irritation study (RCC study number B16086), 0.1 g of Paradimethoxybenzene was instilled into the conjunctival sac of left eye of New Zealand White rabbits (1 male and 2 females). Animals then were observed for 72 hours.

Irritation was scored according to the EU classification criteria.

The mean score was calculated across 3 scoring times (24, 48 and 72 hours after instillation) for each animal for corneal opacity, iris, redness and chemosis of the conjunctivae, separately.

The individual mean scores for corneal opacity and iris were 0.00 for all three animals. The individual mean scores for the conjunctivae were 0.33, 0.33 and 0.67 for reddening, respectively and 0.00 for chemosis for the three animals.

No abnormal findings were observed in the cornea or iris of any animal at any of the measurement intervals In this study, Paradimethoxybenzene is not an eye irritant based on the EU classification criteria.