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

Endpoint summary

Description of key information

Oral LD50 > 300 - 2000 mg/kg bw

Dermal LD50 > 2000 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 - 28 Apr 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

08 Feb 2002

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom, UK

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Remarks:

RccHan:WIST

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS (UK) Limited, Oxon, UK
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 to 12 weeks
- Weight at study initiation: 162 - 211 g
- Fasting period before study: animals were fasted overnight before dosing
- Housing: in groups of up to 4 in suspended solid-floor polypropylene cages furnished with woodflakes
- Diet: 2014C Teklad Global Rodent diet, ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25
- Humidity (%): 30 - 70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

DMSO

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 33.3 and 221.8 mL/kg bw
- Justification for choice of vehicle: DMSO was used because the test item did not dissolve/suspend in distilled water or arachis oil BP

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

CLASS METHOD
- Rationale for the selection of the starting dose: The recommended starting dose of 300 mg/kg bw according to the current OECD TG was used

Doses:

300 and 2000 mg/kg bw (Due to the purity of the test material, the animals were dosed with 333 and 2218 mg/kg bw of the test material, respectively.)

No. of animals per sex per dose:

3 (2000 mg/kg bw/day) and 6 (300 mg/kg bw/day)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals were observed 30 min, 1, 2 and 4 h after dosing and subsequently once daily for up to 14 days. Body weights were determined prior to dosing and on Day 7 and 14 after treatment or at death
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Key result

Sex:

female

Dose descriptor:

LD50 cut-off

Effect level:

500 mg/kg bw

Based on:

test mat.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Mortality:

300 mg/kg bw: 0/6 animals died
2000 mg/kg bw: 1/3 animals killed for humane reasons on Day 1, 2/3 animals died on Day 1

Clinical signs:

other: 300 mg/kg bw: no clinical signs of toxicity were observed up to the end of the 14-day observation period in 6/6 animals 2000 mg/kg bw: hunched posture in 3/3 animals, piloerection, lethargy, diarrhea, hypothermia, tonic convulsions, chromodacryorrhea and

Gross pathology:

300 mg/kg bw: necropsy revealed no substance-related findings in 6/6 animals
2000 mg/kg bw: dark kidneys, gaseous stomach, pale brown colored liquid present in the stomach, hemorrhage and epithelial sloughing of the gastric mucosa and non-glandular epithelium of the stomach in 3/3 animals. Dark liver in 2/3 animals and patchy pallor of the liver in 1/3 animals

Table 1: Acute oral toxicity

Dose	Mortality	Clinical signs
[mg/kg bw]
	N*	N*
Females
300	0/3	0/3
300	0/3	0/3
2000	3/3	3/3

*N = Number of animal / number of animals used

Interpretation of results:

other: Cat. 4, H302 according to Regulation (EC) No 1272/2008

Conclusions:

CLP: Acute Oral 4, H302

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

500 mg/kg bw

Quality of whole database:

Reliable GLP compliant OECD Guideline study; the LD50 is reported as being in the range of 300 to 2000 mg/kg bw.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Oct - 08 Nov 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 24 Feb 1987

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom, UK

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Remarks:

RccHan™:WIST

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS (UK), Limited, Oxon, UK
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 227 - 249 g (males); 209 - 221 g (females)
- Housing: The animals were housed individually during the exposure period and in groups of 5 animals per sex in suspended solid floor polypropylene cages furnished with woodflakes.
- Diet: 2014C Teklad Global Rodent diet (Envigo RMS (UK) Limited, Oxon, UK), ad libitum
- Water: Trinking water, ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25
- Humidity (%): 30 - 70
- Air changes (per hr): At least 15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

DMSO

Remarks:

as moistener

Details on dermal exposure:

TEST SITE
- Area of exposure: clipped skin of the dorsal area of the trunk
- % coverage: 10
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage. Shortly after dosing the dressings were examined to ensure that they were securely in place.

REMOVAL OF TEST SUBSTANCE
- Washing: Yes, the treated skin and surrounding hair was wiped with cotton wool moistened with DMSO to remove any residual test item.
- Time after start of exposure: 24 h

Duration of exposure:

24 h

Doses:

2000 mg/kg bw (due to the purity of the test material, the animals were dosed with 2218 mg/kg bw of the test material)

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for deaths or overt signs of toxicity 30 min, 1, 2 and 4 h after dosing and thereafter once daily for 14 days. The body weights were determined prior to the treatment and on Days 7 and 14.
- Necropsy of survivors performed: yes
- Other: The test sites were examined for evidence of primary irritation after removal of the test substance and subsequently once daily for 14 days, and scored according to the Draize scoring system.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality observed at the dose level of 2000 mg/kg bw.

Clinical signs:

other: There were no systemic clinical signs noted in any animal throughout the study. Very slight erythema (grade 1) was observed at the test sites of all animals up to 5 or 6 days after treatment with the test substance. Crust formation was noted at the test s

Gross pathology:

Necropsy revealed no substance-related findings.

Table 1 Individual Dermal Reactions

Males		Day 1	Day 2	Day 3	Day 4	Day 5	Day 6	Day 7	Day 8	Day 9 - 14
1	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	0	0
2	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	0	0
3	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	Cf	0
4	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Ss	Ss	Ss	Ss
5	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	Cf	0
Females
1	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	0	0
2	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	0	0
3	Erythema	1	1	1	1	1	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	Cf	0
4	Erythema	1	1	1	1	1	1	0	0	0
	Other	0	0	0	0	0	0	0	0	0
5	Erythema	0	0	0	0	0	0	0	0	0
	Other	0	0	0	0	0	Cf	Cf	0	0

0 = No reaction

Cf = Crust formation

Ss = Small superficial scattered scabs

Interpretation of results:

other: CLP/EU GHS criteria not met; no classification required according to Regulation (EC) No. 1272/2008

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Oral

An acute oral toxicity study (limit test) was performed with the registered substance according to OECD guideline 423 and GLP conditions (Envigo Research, 2016). In the sighting study 3 fasted female Wistar rats received a single oral gavage dose of 333 mg/kg bw (equivalent to 300 mg active ingredient/kg bw). Since no mortality was observed, further three fasted female rats were treated at dose levels of 2218 mg/kg bw (equivalent to 2000 mg active ingredient/kg bw) and 333 mg/kg bw. All animals were observed for mortality and evident signs of toxicity 30 min, 1, 2 and 4 after dosing and subsequently once daily for up to 14 days. The body weight was recorded prior to dosing, and 7 and 14 days after dosing. At the end of the observation period the surviving animals were killed by cervical dislocation and subjected to gross pathological examination. No mortality and no evidence for systemic toxicity occurred at 333 mg/kg bw. At the high-dose level 2 females were found dead 1 day after dosing and 1 female was killed for humane reasons, 1 day after dosing due to severe clinical signs. Clinical signs, such as hunched posture, piloerection, lethargy, diarrhea, hypothermia, tonic convulsions, chromodacryorrhea and splayed gait were noted for the high-dose females. At necropsy, abnormalities, such as dark liver or patchy paller of the liver, dark kidneys, gaseous stomach, pale brown colored liquid present in the stomach, hemorrhage and epithelial sloughing of the gastric mucosa and non-glandular epithelium of the stomach, were observed for the females of the high-dose group. Based on the results of the conducted study, the acute oral LD50 was found to be > 333 – 2218 mg/ kg bw (equivalent to 300 – 2000 mg active ingredient/kg bw). According to the current OECD Guideline, the acute oral LD50 cut-off value of the test substance was considered to be 555 mg/kg bw (equivalent to 500 mg/kg bw).

 

Dermal

An acute dermal toxicity study (limit test) was performed with the registered substance according to OECD guideline 402 and GLP conditions (Envigo Research, 2017). In a limit test, 5 male and 5 female Wistar rats were exposed to 2000 mg test substance /kg bw for 24 h on the back skin under semiocclusive conditions. The animals were observed for deaths or overt signs of toxicity 30 min, 1, 2 and 4 h after dosing and thereafter once daily for 14 days. The body weights were determined prior to the treatment and on Days 7 and 14, and a necropsy was performed at the end of the observation period. No mortality was observed. There were no systemic clinical signs noted in any animal throughout the study. Very slight erythema (grade 1) was observed at the test sites of all animals up to 5 or 6 days after treatment with the test substance. Crust formation was noted at the test sites from Day 6 to Day 7 or 8 in 4/5 males and 4/5 females. Small superficial scattered scabs were observed at the test site of one male from Day 4 to Day 14. Body weight gains and necropsy at study termination revealed no abnormalities. Based on the results of the conducted study, the acute dermal LD50 in rats was found to be greater than 2000 mg/kg bw.

Justification for classification or non-classification

The available data on acute oral toxicity with Zinc, bis[O,O-bis(1-methylethyl) phosphorodithioato-.kappa.S]bis(cyclohexanamine)-, (T-4)- (CAS 52585-16-7) meet the classification criteria according to Regulation (EC) No 1272/2008, and therefore the substance will be classified as Acute oral Cat. 4, H302.

The available data on acute dermal toxicity with Zinc, bis[O,O-bis(1-methylethyl) phosphorodithioato-.kappa.S]bis(cyclohexanamine)-, (T-4)- (CAS 52585-16-7) do not meet the criteria for classification according to Regulation (EC) No 1272/2008, and are therefore conclusive but not sufficient for classification.