Registration Dossier

Administrative data

Description of key information

Dicyandiamide is practical non-toxic in primary skin and eye irritation tests according Draize (1944) and FDA-standards (1963) respectively, when applied at a concentration of 0.5 g to the abraded and the intact skin or 0.1g instilled into the eyes of albino rabbits. 

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:
1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions
Qualifier:
no guideline available
Principles of method if other than guideline:
Patch-test technique according Draize (J. Pharmacol. (1944) 82; 377).
GLP compliance:
not specified
Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: adult


Type of coverage:
occlusive
Preparation of test site:
other: abraded and intact skin
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
0.5 g
Duration of treatment / exposure:
24 hours
Observation period:
72 hours
Number of animals:
12
Details on study design:
Primary irritation to the skin is measured by a patch-test technique on the abraded and the intact skin of albino rabbits.
Twelve healthy adult New Zealand White albino rabbits were used for the test substance. 24 hours prior to applying the materials, the hair is removed from the backs of the animals with an electric clipper in such a way as to avoid abrasions.
An amount of 0.5 g of Dicyandiamide was brought into contact of the intact and the abraded skin under a surgical patch measuring 1 inch x 1 inch. The patches are fixed to the application site by means of adhesive tape and the entire trunk of the rabbits is wrapped with an impervious material to maintain the test patches in position and to retard evaporation of volatile substances.
Six rabbits are treated on the intact skin, the other six on the abraded skin. The abrasions are minor incisions through the stratum corneum, but not sufficiently deep to disturb the derma or to produce bleeding.
After an exposure period of 24 hours the patches and the material applied are removed and the resulting skin reactions are evaluated by the method of Draize (J. Pharmacol. 82 (1944) 377-). A second reading is made 48 hours later (72 hours after application).
In the case of surface active test substances the skin reactions after 72 hours usually consist of scaliness and/or necrosis. Since the Draize grading system does not comprise these abnormalities the second reading is carried out on the basis of the CIVO-grading system.
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #4
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #5
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #6
Time point:
24 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 72h
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #2
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #3
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #4
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #5
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #6
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #4
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #5
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #6
Time point:
72 h
Score:
1
Max. score:
4
Reversibility:
not specified
Remarks on result:
other: very slight scaliness
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #1
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
not specified
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #2
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #3
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #4
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #5
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
other: n.a
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #6
Time point:
72 h
Score:
0
Max. score:
4
Reversibility:
not specified
Remarks on result:
no indication of irritation
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #4
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #5
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
erythema score
Basis:
animal #6
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #1
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #2
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #3
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #4
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #5
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Irritation parameter:
edema score
Basis:
animal #6
Time point:
48 h
Reversibility:
other: n.a
Remarks on result:
not measured/tested
Remarks:
intact skin
Other effects:
No other effects

Table 2: Individual and average skin irritation scores of the product dicyandiamide

Rabbit no.

Intact skin

Rabbit no.

Abraded skin

24 hours

72 hours

24 hours

72 hours

A

B

 

A

B

 

1

0

0

0

7

0

0

1

2

0

0

0

8

1

0

0

3

0

0

0

9

0

0

0

4

0

0

0

10

0

0

0

5

0

0

0

11

1

0

0

6

1

0

0

12

0

0

1

A = erythema

B = edema

Interpretation of results:
GHS criteria not met
Conclusions:
The test material dicyandiamide is practically non-irritating to the skin of rabbits.
Executive summary:

Primary irritation to the skin was measured by a patch-test technique on the abraded and the intact skin of albino rabbits.

Twelve healthy adult New Zealand White albino rabbits were used for 0.5 g of the test substance Dicyandiamide which was brought into contact of the intact and the abraded skin.

After an exposure period of 24 hours the patches and the material applied were removed and the resulting skin reactions were evaluated by the method of Draize. A second reading was made 48 hours later (72 hours after application).

The test material caused very slight erythema in one out of six rabbits treated on the intact skin and in two out of six rabbits treated on the abraded skin.

After 72 hours no dermal effects were observed in rabbits that had been on the intact skin, whereas slight scaliness was observed in two rabbits that had been treated on the abraded skin.

It may be concluded that the test material dicyandiamide is practically non-irritating to the skin of rabbits.

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:
1977
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Qualifier:
according to
Guideline:
other: Fed. Reg. 28 (119), 5582, 1963 (published by the FDA of the USA) and Draize and Kelley (Drug. Cosmet. Industr. 71 (1952) 36)
Deviations:
yes
Remarks:
: no reading after one hour
GLP compliance:
not specified
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Housing: individually
- Diet: they received no hay or other extraneous material that might enter the eyes
- The eyes of the animals were examined before testing and only those animals without observable eye defects are used
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 g
Duration of treatment / exposure:
- Single treatment
- test substance was allowed to fall on the everted lower lid of one eye of each rabbit; the upper and lower eye lid were then carefully closed and subsequently held together for at least one second before releasing, to prevent loss of material
- the untreated eye served as control
- the eyes were not washed following instillation and the animlas were released immediately
Observation period (in vivo):
24, 48 72 hours and 7 days after instillation of the test material
Number of animals or in vitro replicates:
six animals
Details on study design:
SCORING SYSTEM (FDA scoring scale):
- an animal is considered as giving a positive reaction if there is, at any of the readings:
* discernable opacity of the cornea (other than slight dulling of the normal lustre), or
* ulceration of the cornea, or
* inflammation of the iris (other than a slight deepening of the folds (rugae) or a slight circumcorneal injection), or if such substances produce
* obvious swelling in the conjunctivae (palpebral and bulbar, excluding the cornea and the iris) with partial eversion of the lids, or
* diffuse deep-crimson red with individual vessels not easily discernible
- the test is considered positive if four or more of the animals in the test group of six rabbits exhibit a positive reaction
- if one animal exhibits a positive reaction, the test is regarded as negative
- if two or three animals exhibit a positive reaction, the test is repeated, using a different group of six animals
- the second test is considered as positive if three or more of the animals exhibit a positive reaction
- if only one or two of the animals in the second test exhibit a positive reaction, the test is again repeated with a different group of six animals
- should a third test be needed, the substance will be regarded as an irritant if two or more animals exhibit a positive response

TOOL USED TO ASSESS SCORE:
- oculat reactions are read using a binocular magnifying glass
- the diagnosis of corneal damage is confirmed, if necessary, by staining the eyes of the animals with fuorescein-impreganted papers
- after flushing the excess fluorescein solution, the eyes are examined in a dark room under ultraviolet illumination

A substance which has elicited corneal and/or iris lesions which have not cleared by the seventh day reading, is considerd a severe eye irritant.
Irritation parameter:
cornea opacity score
Basis:
mean
Time point:
24/48/72 h
Score:
< 1
Max. score:
4
Reversibility:
fully reversible within: 48 h
Remarks on result:
other: only in animal #3 cornea score 1; all others were scored 0
Irritation parameter:
iris score
Basis:
mean
Time point:
24/48/72 h
Score:
< 1
Max. score:
2
Reversibility:
fully reversible within: 48 hours
Remarks on result:
other: only in animal #3 iris score 1; all others were scored 0
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
mean
Time point:
24/48/72 h
Score:
> 1 - < 2
Max. score:
3
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: after 7 days animals # 4 and 6 were still scored 1 (scores after 24 h: > 1 and 1, respectively); all other animals were scored 0
Irritation parameter:
chemosis score
Basis:
mean
Time point:
24/48/72 h
Score:
> 1 - < 2
Max. score:
4
Reversibility:
fully reversible within: 72 h
Remarks on result:
other: exception: animal #4, chemosis was fully reversible within 7 days
Irritation parameter:
cornea opacity score
Basis:
mean
Time point:
7 d
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
mean
Time point:
7 d
Score:
0
Max. score:
2
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
mean
Time point:
7 d
Score:
< 1
Max. score:
3
Irritation parameter:
chemosis score
Basis:
mean
Time point:
7 d
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
- The test material caused slight corneal damage, slight irititis and moderate redness and swelling of the conjunctivae in one rabbit and slight redness of the conjunctivae in the other five rabbits.
- During the seven-day observation period these eye lesions recovered incompletely so that at the seventh day reading slight redness of the conjunctivae was still observed in two out of six rabbits.
Other effects:
No other effects observed.

Table 2: Individual scores awarded to the ocular lesions elicited by Dicyandiamid

Rabbit No

cornea

iris

conjuntivae

redness

chemosis

After 24 hours

1

0

0

1

1

2

0

0

> 1

1

3

1

1

< 2

2

4

0

0

> 1

1

5

0

0

1

1

6

0

0

1

1

After 48 hours

1

0

0

1

0

2

0

0

1

1

3

0

0

1

1

4

0

0

1

1

5

0

0

1

0

6

0

0

 >1

1

After 72 hours

1

0

0

1

0

2

0

0

1

0

3

0

0

1

0

4

0

0

1

1

5

0

0

1

0

6

0

0

 >1

0

After 7 days

1

0

0

0

0

2

0

0

0

0

3

0

0

0

0

4

0

0

1

0

5

0

0

0

0

6

0

0

1

0

 

Interpretation of results:
GHS criteria not met
Conclusions:
Based on the results of this test and according to the FDA-standard the test material is not considered to be an eye irritant.
Executive summary:

In an acute eye irritation study according to FDA-standards, 0.1 ml of Dicyandiamid was instilled into the eyes of six albino rabbits (New Zealand White strain). Eyes were not washed afterwards. Animals then were observed after 24, 48, 72 hours and 7 days. Irritation was scored by the method of US EPA 560/6-82-001.

Under the experimental conditions employed, Dicyandiamid produced slight corneal damage, slight irititis and moderate redness and swelling of the conjunctivae in one rabbit and slight redness of the conjunctivae in the other five rabbits. During the seven-day observation period these eye lesions recovered incompletely so that at the seventh day reading slight redness of the conjunctivae was still observed in two out of six rabbits.

According to the FDA-standard the test material is not considered to be an eye irritant.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Additional information

Primary irritation to the skin was measured by a patch-test technique on the abraded and the intact skin of 12 adult New Zealand White albino rabbits. After an exposure period of 24 hours the patches and the material applied were removed and the resulting skin reactions were evaluated by the method of Draize. A second reading was made 48 hours later (72 hours after application). Since the Draize grading system does not comprise abnormalities found in a second reading after 72h these were carried out on the basis of the CIVO-grading system. The test material caused very slight erythema in one out of six rabbits treated on the intact skin and in two out of six rabbits treated on the abraded skin. After 72 hours no dermal effects were observed in rabbits that had been treated on the intact skin, whereas slight scaliness was observed in two rabbits that had been treated on the abraded skin. According the CIVO-grading systems dicyandiamide is practically non-irritating to the skin of rabbits.

In an acute eye irritation study according FDA-standards, 0.1 ml of Dicyandiamid was instilled into the eyes of six New Zealand White albino rabbits. Eyes were not washed after application. Animals then were observed after 24, 48, 72 hours and 7 days. Irritation was evaluated using the scoring system of US EPA 560/6-82-001. The test material caused slight corneal damage, slight irititis and moderate redness and swelling of the conjunctivae in one rabbit and slight redness of the conjunctivae in the other five rabbits. During the seven-day observation period these eye lesions recovered incompletely so that at the seventh day slight redness of the conjunctivae was still observed in two out of six rabbits. Based on the results of this test and according to the FDA-standard the test material is not considered to be an eye irritant in rabbits.

Justification for classification or non-classification

Practically non-irritating to the skin according Draize and CIVO grading system. Practically non-irritating to the eye according to FDA-standards.