Bis(O,O-diisopropyl dithiophosphate)bis(cyclohexylamine) zinc

Endpoint summary

Description of key information

Skin irritation (in vivo, Draize testing method): irritant

Eye irritation (in vivo, Draize testing method): serious eye damage

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Draize Testing method (Draize JH et al., J. Pharm. Exp. Ther. 82: 377-390, 1944; Draize JH, Assoc. Food Drugs Officials of the United States: 46-49, Topeka Kansas, 1965) as prescribed by the FDA (in The Federal Register 38 No.187 §15000.41, USA)

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: L.I.T., Aptos, USA
- Weight at study initiation: 2 - 2.5 kg
- Housing: individually
- Diet: 2 oz/day (equivalent to 56.7 g/day) Purina Rabbit Chow
- Water: ad libitum

Type of coverage:

occlusive

Preparation of test site:

other: shaved and abraded

Vehicle:

water

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g mixed to a paste with 10 drops of water

VEHICLE
- Amount(s) applied (volume or weight with unit): 10 drops

Duration of treatment / exposure:

24 h

Observation period:

6 days
Reading time points: 0 and 48 h, and 6 days

Number of animals:

6 males

Details on study design:

TEST SITE
- Area of exposure: dorsal area of the trunk
- Type of wrap if used: the treated skin was covered with a 2.5 cm² 2-layer surgical gauze patch, held in place by clear plastic wrap. The trunk of each animal was then wrapped in Spandex.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): if test substance was still present on the skin, the treated area was swabbed with warm water
- Time after start of exposure: 24 h

SCORING SYSTEM: Draize scoring system

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

Intact skin:
For one of the rabbits no test substance was observed at the test site at patch removal, and very slight erythema (score 1) and no edema was noted (see Table 1 under 'Any other information on results incl. tables'). The results for this animal (number 4) were disregarded. Directly after patch removal (24 h), 5/5 animals had well defined to severe erythema (score 2 - 3), while 4/5 had slight to moderate edema (score 2 - 3) and 1/5 had very slight edema (score 1). 48 hours after patch removal, 5/5 rabbits had very slight to well defined erythema (score 1 - 2). The edema had cleared in 4/5 animals, while 1/5 still had very slight edema (score 1). 6 days after patch removal, 3/5 rabbits had very slight erythema (score 1) and 1/5 also had very slight edema (score 1), whereas in 2/5 rabbits all skin effects had cleared. The skin irritation effects were read 0 and 48 h after patch removal, while the exposure time was 24 h (as opposed to 4 h requirement in OECD guideline 404). No 24- and 72 h readings are available. However, a worst case approach was used to calculate the mean value (24/48/72 h) of the erythema and edema score, respectively. Since the animals were exposed 24 h with the test substance, the 0-h reading time point was assumed to be the 24-h reading time point and the 48-h reading time point was assumed to be the 72-h reading time point. The 48 h values were assumed to be the same as those at 24 h (worst case assumption: persistence of effects seen at 24 h over 48 h).

Abraded skin:
For one of the rabbits no test substance was observed at the test site at patch removal, and very slight erythema (score 1) and no edema was noted. The results for this animal (number 4) were disregarded. Directly after patch removal (24 h), 5/5 animals had well defined to severe erythema (score 2 - 3) and 5/5 had slight to moderate edema (score 2 - 3). 48 hours after patch removal, 5/5 rabbits had very slight to well defined erythema (score 1 - 2). 1/5 rabbits had very slight edema (score 1), while the edema had cleared in 4/5 animals. 6 days after pach removal, 3/5 rabbits had very slight erythema, while the edema had cleared in 5/5 rabbits.

Table 1: Individual skin irritation scores (intact skin)

Observation time	Rabbit no.
	1		2		3		4		5		6
	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema
24 h	2	2	2	2	3	2	1*	0	3	3	3	1
48 h	No experimental data available; for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption)
72 h	2	0	1	0	1	0	-	-	1	1	1	0

* The material was not present at the time of unwrapping (24 h reading). However, there was a slight erythema at the sites of application. These values will not be used in calculating.

Table 2. Calculation of mean scores

	Rabbit no.
	1		2		3		4		5		6
	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema	Erythema	Edema
Mean value 24 + 48 + 72 h*	2,0	1,3	1,7	1,3	2,3	1,3	-	-	2,3	2,3	2,3	0,7

*No 48 h data are available: for calculation of mean scores, the 48 h values were assumed to be the same as those at 24 h (worst case assumption: persistence of effects seen at 24 h over 48 h).

Interpretation of results:

other: Cat. 2, H315 according to Regulation (EC) No 1272/2008

Conclusions:

CLP: Cat. 2, H315.
A worst case approach was used to calculate the mean value (24/48/72 h) of the erythema and edema score, respectively. Based on this, a skin irritant potential for the test substance is assumed and accordingly, classification is warranted.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

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:

comparable to guideline study with acceptable restrictions

Remarks:

(Basic data given. Limited data on animal husbandry, test substance purity not specified.)

Qualifier:

no guideline followed

Principles of method if other than guideline:

Draize Testing method (Draize JH et al., J. Pharm. Exp. Ther. 82: 377-390, 1944) as prescribed by the FDA (in The Federal Register 38 No.187 §15000.42, USA).

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Housing: individually
- Diet: 2 oz/day (equivalent to 56.7 g/day) Purina Rabbit Chow
- Water: ad libitum

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated eye served for control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.1 g

Duration of treatment / exposure:

single application without washing

Observation period (in vivo):

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

Number of animals or in vitro replicates:

6

Details on study design:

SCORING SYSTEM: Draize scoring system

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

1.61

Max. score:

4

Reversibility:

not fully reversible within: 7 days in 6 animals

Remarks on result:

other: The chemosis effect was so severe that only 25% of the cornea was observable. The cornea scores are a minimum of the approximated score, however, maximum scores of up to 4 were included in the study report between bracket.

Irritation parameter:

iris score

Basis:

mean

Remarks:

of 5 animals

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

not fully reversible within: 7 days in 3 animals. For 2 of these animals no score could be given on day 7.

Remarks on result:

other: The chemosis effect was so severe that only 25% of the iris was observable. For 1/6 animals no iris scores could be assigned at any reading time point; for 1/6 animals no score was assigned at the 7-day reading time point.

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

of all 6 animals

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 7 days in 6 animals

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

3.39

Max. score:

4

Reversibility:

not fully reversible within: 7 days in 2 animals

Remarks on result:

other: Fully reversible within: 7 days in 4 animals

Irritant / corrosive response data:

The chemosis was so severe that only 25% of the cornea and iris were observable. The cornea scores are the minimum score given, however, a maximum score of up to 4 was included in the study report between brackets, indicating that scoring was difficult (see Table 1 and Table 2 under 'Any other information on results incl. tables'). Some corneal effects (score 1 - 2) were observed in 6/6 animals at the 24-, 48-, 72- and 96-hour reading time points. 7 days after instillation, the effects remained the same in 4/6 animals, and had become more severe (score 3) in 2/6 animals. In general, a worsening of the severity was observed in 4/6 animals during the observation period, while it remained the same for 2/6 animals. The highest conjunctivae score of 3 was assigned 6/6 animals at the 24-, 48- and 72-hour reading time points. The severity was reduced in 4/6 animals (score 1 - 2) 7 days after instillation and remained unchanged (score 3) in 2/6 animals. The conjunctivae was irreversible in 6/6 animals. The chemosis was severe (score 3 - 4) in all animals at the 24-, 48- and 72-hour reading time points. 96 hours after instillation, the effect had reduced in severity in 4/6 animals (score 1 - 2) while the severity was unchanged in 2/6 animals (score 3 - 4). At the 7-day reading time point, the chemosis had reversed completely in 4/6 animals, while in 2/6 the effect was still present (score 2 and 4, respectively). In 5/6 animals the iris effects were marked (score 1) from the 24-hour reading time point until the 96-hour reading time point. For 1/6 animals it was not possible to assign an iris score at any reading time point. 7 days after application, the effects has cleared in 3/6 animals, the effects remained marked (score 1) in 1/6, and for 2/6 animals it was not possible to assign an iris score.

Table 1: Individual eye irritation scores

 

Rabbit #	Time	conjunctivae		iris**	cornea***
		redness	swelling
1	24 h	3	4	?	2
	48 h	3	4	?	2
	72 h	3	4	?	2
	96 h 7 d	3 3	4 4	? ?	2 3
	Average*	3.0	4.0	-	2.0
2	24 h	2.5	3	1	1
	48 h	3	3	1	1
	72 h	3	3	1	2
	96 h 7 d	2 1	1 0	1 0	2 2
	Average*	3.0	3.0	1.0	1.33
3	24 h	3	4	1	1
	48 h	3	3	1	1
	72 h	3	3	1	2
	96 h 7 d	3 2	3 0	1 0	2 2
	Average*	3.0	3.33	1.0	1.33
4	24 h	3	4	1	2
	48 h	3	4	1	2
	72 h	3	3	1	2
	96 h 7 d	3 1	2 0	1 0	2 2
	Average*	3.0	3.67	1.0	2.0
5	24 h	3	4	1	1
	48 h	3	3	1	2
	72 h	3	3	1	2
	96 h 7 d	3 1	1 0	1 1	2 2
	Average*	3.0	3.33	1.0	1.67
6	24 h	3	3	1	1
	48 h	3	3	1	1
	72 h	3	3	1	2
	96 h 7 d	3 3	2 2	1 ?	2 3
	Average*	3.0	3.0	1.0	1.33

*(24h+48h+72h)/3.

** Only 25% of the iris was observable due to severe chemosis; the eye of animal 1

could not be scored at all and the eye of animal 6 could not be socred on day 7.

*** Only 25% of the cornea was observable due to severe chemosis.

The cornea scores are the minimum score given, however, a maximum score

(up to 4) was included in the study report between brackets indicating that scoring was difficult.

Table 2: Individual minimum and maximum cornea scores

Observation time	Rabbit No.
	1		2		3		4		5		6
Cornea score	Minimum	Maximum	Minimum	Maximum	Minimum	Maximum	Minimum	Maximum	Minimum	Maximum	Minimum	Maximum
24 h	2	4	1	4	1	3	2	2	1	4	1	4
48 h	2	4	1	3	1	2	2	2	2	3	1	4
72 h	2	4	2	3	2	2	2	3	2	4	2	4
7 days	3	4	2	2	2	2	2	2	2	1	3	4

 

Interpretation of results:

other: Cat. 1, H318 according to Regulation (EC) No 1272/2008

Conclusions:

CLP: Cat. 1, H318

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

The skin irritation potential of the registered substance was determined by an in vivo skin irritation test according to the Draize Testing method (Cutter Laboratories, 1977). In this study, 0.5 g mixed to a paste with 10 drops of water were applied to the shaved dorsal area of the trunk of each of 6 male NZW rabbits for 24 h under occlusive conditions. The skin was observed for erythema and/or edema immediately, 48 h and 6 days after the 24-h treatment period. For 1/6 rabbits no test substance was observed at the test site at patch removal, and very slight erythema (score 1) and no edema was noted, therefore the results for this animal were disregarded. Directly after patch removal, 5/5 animals had well defined to severe erythema (score 2 - 3), while 4/5 had slight to moderate edema (score 2 - 3) and 1/5 had very slight edema (score 1). 48 hours after patch removal, 5/5 rabbits had very slight to well defined erythema (score 1 - 2). The edema had cleared in 4/5 animals, while 1/5 still had very slight edema (score 1). On day 7, 3/5 rabbits had very slight erythema and 1/5 also had very slight edema. The skin effects had cleared in 2/5 rabbits, but were not fully reversible up to the end of the observation period of 7 days in 3/5 rabbits. Based on the results of the conducted study, the test substance is considered to exhibit irritant properties towards the skin.

 

Eye

The eye irritation potential of the registered substance was determined by an in vivo eye irritation test according to the Draize Testing method (Cutter Laboratories, 1977). In this study, 0.1 g of the test substance was instilled into the eye of each of 6 NZW rabbits by a single application without washing. The rabbits were observed 24, 48, 72 and 96 h and 7 days after exposure with the test substance. The chemosis was so severe that only 25% of the cornea and iris were observable. The cornea scores are the minimum score given, however, a maximum score of up to 4 was included in the study report between brackets, indicating that scoring was difficult. Some corneal effects (score 1 - 2) were observed in 6/6 animals at the 24-, 48-, 72- and 96-hour reading time points. 7 days after instillation, the effects remained the same in 4/6 animals, and had become more severe (score 3) in 2/6 animals. In general, a worsening of the severity was observed in 4/6 animals during the observation period, while it remained the same for 2/6 animals. The highest conjunctivae score of 3 was assigned 6/6 animals at the 24-, 48- and 72-hour reading time points. The severity was reduced in 4/6 animals (score 1 - 2) 7 days after instillation and remained unchanged (score 3) in 2/6 animals. The conjunctivae was irreversible in 6/6 animals. The chemosis was severe (score 3 - 4) in all animals at the 24-, 48- and 72-hour reading time points. 96 hours after instillation, the effect had reduced in severity in 4/6 animals (score 1 - 2) while the severity was unchanged in 2/6 animals (score 3 - 4). At the 7-day reading time point, the chemosis had reversed completely in 4/6 animals, while in 2/6 the effect was still present (score 2 and 4, respectively). In 5/6 animals the iris effects were marked (score 1) from the 24-hour reading time point until the 96-hour reading time point. For 1/6 animals it was not possible to assign an iris score at any reading time point. 7 days after application, the effects has cleared in 3/6 animals, the effects remained marked (score 1) in 1/6, and for 2/6 animals it was not possible to assign an iris score. Based on the results of the conducted study, the test substance is considered to cause serious eye damage.

Justification for classification or non-classification

The available data on skin irritation and eye irritation meet the criteria for classification according to Regulation (EC) 1272/2008, therefore the registered substance will be classified for skin irritation in Cat. 2, H315 and for serious eye damage in Cat. 1, H318.