Butyric acid

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards; basic data given, comparable to guideline study (deviations: dose only 50 µL, observation period 8 d)

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Reference 2

Reference Type:

other company data

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Principles of method if other than guideline:

Acute eye irritation test; specific internal BASF standard method

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Butyric acid

EC Number:

203-532-3

EC Name:

Butyric acid

Cas Number:

107-92-6

Molecular formula:

C4H8O2

IUPAC Name:

butyric acid

Details on test material:

- Name of test material (as cited in study report): n-Buttersaeure (Butanoic acid)
- Analytical purity: 99 %

Test animals / tissue source

Species:

rabbit

Strain:

Vienna White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Gaukler
- Weight at study initiation: male: 3.12 kg; male: 3.05 kg

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The adjacent eye served as saline control

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.05 ml

Duration of treatment / exposure:

8 days

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

2

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24h-48 h

Score:

0

Max. score:

1

Reversibility:

not fully reversible within: 8 days

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24h-48h

Score:

3.25

Max. score:

4

Reversibility:

not fully reversible within: 8 days

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24h-48h

Score:

2.75

Max. score:

3

Reversibility:

not fully reversible within: 8 days

Results 4

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24h-48h

Score:

0.25

Max. score:

4

Reversibility:

not fully reversible within: 8 days

Irritant / corrosive response data:

risk of serious damage to eyes

Any other information on results incl. tables

	1 h		24 h		48 h		8 days
Animal No.	1	2	1	2	1	2	1	2
Erythema	*	*	*	1	*	*	1	*
Opacity	3	2	4	2	4	3	4	3
Chemosis	2	2	3	3	3	2	2	3
Iritis	0	0	0	0	0	0	0	1

* no data given

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In an acute eye irritation test using an internal BASF method, butyric acid caused irreversible damage to the rabbit's eye after application of 50 µL test substance. This is only half of the volume required by test guidelines (OECD, EU). Under test conditions completely conform to guideline requirements, the effects observed will be even more pronounced.

Executive summary:

In a primary eye irritation test, 50 µL of butyric acid (purity 99%) was instilled into the conjunctival sac of one eye each of two male Vienna White rabbits. Animals then were observed for 8 days. The original irritation readings were converted to the Draize score at a later date. Readings were taken 24 h, 48 h, and 8 d after application of test substance.

 

The treated eyes showed severe opacity and chemosis, which persisted until the end of the observation period (8 d) with no tendency to subside.

 

In this study, butyric acid was tested to be corrosive to the eye (irreversible effects on the eye - Category 1) based on the irreversibility of the effects observed.

 

This pre-guideline study bears some deviations from actual test guidelines (amount of test substance, observation period, time of irritation score readings). Nevertheless, the data are assessed to be sufficiently valid to represent the eye damaging potential of butyric acid, as the correct amount of test substance would result in even more pronounced effects. Using available results conforms to the tiered testing and evaluation strategy for eye irritation/corrosion and further testing can be avoided.