Sodium thiocyanate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

08 December 1998 - 30 December 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was performed according to internationally accepted guidelines and under GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

Identification: Ammonium thiocyanate
Description: White crystalline solid
Chemical name: Thiocyanic acid, ammonium salt
Cas - no: 1762-95-4
Batch: 0609810070729
Purity: 99.9% pure (from CoA)
Test substance storage: In refrigerator in the dark
Stability under storage: stable
Expiry date: 14 October 2001
Density: 1300 kg /m3
Bulk density: 600 - 700 kg /m3
Specific Gravity: 1.3
Stability in vehicle: Water :at least 96 h
Rationale for vehicle: The vehicle was selected based on trial formulations performed at NOTOX and/or test substance data supplied by the sponsor.

Test animals

Species:

other: Japanese quail (Coturnix coturnix faponica)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: H. und E. Kilberich, Geesdorf, Germany
- Age at study initiation: 8 weeks
- Weight at study initiation: males : 182 - 254 g of treatment females: 185 - 234 g. The weight of one male was slightly outside the range given in the protocol. This deviation was considered not to have affected the study integrity.
- Fasting period before study: Prior to dosing food was withheld for If to 20 hours.
- Housing: Individual housing in stainless steel wire mesh, battery type cages (dimensions: 16 crn x 27 cm and a height of 20-23 cm).
- Diet (e.g. ad libitum): Free access to a standard commercial avian diet, (= basal diet) Special Diet Services, Witham, Essex, United Kingdom.
- Water (e.g. ad libitum): Free access to tap water.
- Acclimation period: 15 days under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 15.5-23
- Humidity (%): 56-68
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 8/16

IN-LIFE DATES: 16 December 1998 - 30 December 1998

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: Concentration of test substance in vehicle was varied to allow constant dosage volume in terms of ml/kg body weight.
- Amount of vehicle (if gavage): doding volume was maximally 5 ml/kg
- Justification for choice of vehicle: The vehicle was selected based on trial formulations performed at NOTOX and/or test substance data supplied by the sponsor.
- Lot/batch no. (if required): not applicable
- Purity: not applicable

MAXIMUM DOSE VOLUME APPLIED: 5 ml/kg

DOSAGE PREPARATION (if unusual): The test formulation was homogenised to a visually acceptable level by stirring. The test formulation was dosed within 2 hours after preparation.

Doses:

191, 343, 617, 1111 and 2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality:
On day of dosing: continuously during the first 1 to 2 hours after dosing, and subsequently every 2 hours (at least three times). During remainder of study period: twice a day.
Clinical signs:
On day of dosing: continuously during the first 1 to 2 hours after dosing, and subsequently every 2 hours (at least three times). Durjng remainder of study period: once a day. All signs of reaction to treatment were recorded and graded according to fixed scales (specified in the report). The time of onset and duration was recorded. Mortality and clinical signs were recorded in the computer.
Body weights:
Day before dosing (when capsules are used), day 1 (day of dosing), day 8, day 15 and at death (from day 2 onwards).
- Necropsy of survivors performed: yes, necropsy and descriptions of all internal macroscopic abnormalities were recorded. Gross necropsies included general inspection of the gastrointestinal tract, liver , kidney, heart and spleen.
- Other examinations performed:
Food consumption:
Food consumption was monitored from days 1-4, 4-8, 8-11 and 11-15.

Statistics:

The LD50 value, the associated 95% confidence limits and the slope of the dose-response line were calculated in terms of the quantity of active ingredient or total formulation (as appropriate) per unit body weight. The LD50 value was calculated using the Maximum Likelihood method (Finney, D.G.,
Probit Analyses, 3rd Edition, London, Cambridge University Press, 1971). Group means were calculated for continuous data.
The following statistical methods were used to analyse body weights and food consumption:
- Since variables were assumed to follow a normal distribution, the Dunnett test (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
Test statistics were calculated on the basis of exact values for means and pooled variances. Individual values, means and standard deviations may have been rounded off before printing. Therefore, for example, two groups may display the same printed means for a given parameter, yet display different test statistics values.
The test is invalid if more than 10% o f the birds in the control group die. No compound-related, observable toxic effects should be recorded in the lowest test concentration.

Results and discussion

Preliminary study:

Treatment:
The test substance was administered as a single dose by oral gavage using water {milli-U) as a vehicle at dose concentrations of 20, 200 and 2000 mg/kg body weight. The dose volume was 5 ml/kg body weight. One male and one female were used per dose group.
Observations:
Birds were checked for mortality, clinical signs and body weights in a similar way as described for the main study with the exception that the study
continued for 8 days.
Results:
The two birds of the 2000 mg/kg group died within one hour after dosing. Clinical signs observed were clonic spasms, tremors of the head, ventrolateral recumbency, hunched posture, uncoordinated movements, breathing abnormalities, fluid faeces and ptosis in the highest dosage group prior to death. Fluid faeces was noted at 200 mg/kg and 20 mg/kg. No effects on body weights were found in the surviving birds.
Conclusions:
Based on these results it was decjded to conduct a full study with dose levels selected to be 0, 191, 343, 617, 1111 and 2000 mg/kg body weight.

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

508 mg/kg bw

95% CL:

349 - 693

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

508 mg/kg bw

95% CL:

285 - 790

Effect levels 3

Sex:

male

Dose descriptor:

LD50

Effect level:

508 mg/kg bw

95% CL:

285 - 790

Mortality:

None of the animals died in group 1-3 (0, 191, 343 mg/kg bw) and all animals died in groups 4-6 (617, 1111, 2000 mg/kg bw) .All deaths of group 4 (617 mg/kg) were recorded within 5 hours after dosing except for one male, which was found dead on day 2 after treatment. Four deaths of group 5 (1111 mg/kg) were observed within 3 hours, the remaining deaths of this group and all of group 6 (2000 mg/kg) were recorded within 1 hour after dosing.

Clinical signs:

other: The following clinical findings were noted: 0 mg/kg: Fluid faeces until 3 hours after dosing in all birds. 191 mg/kg: Fluid faeces until 5 hours after dosing in all birds. 343 mg/kg : Fluid faeces until day 2 in all birds. Uncoordinated movements, letharg

Gross pathology:

0 mg/kg: No findings noted.
191 mg/kg: No findings noted.
343 mg/kg: No findings noted.
617 mg/kg: Haemorrhages in the intestines, swollen andlor dark red liver, a dark red spleen and a detached cuticle of the
stomach were noted among the birds.
1111 mg/kg: Haemorrhages in the intestines, swollen andlor dark red liver, and detached cuticles of the stomach were noted
among the birds.
2000 mg/kg: Haemorrhages in the intestines, swollen andlor dark red liver and detached cuticles of the stomach were noted among
the birds.

The findings in the dosage groups of 617 mg/kg and above were considered to be adverse effects of treatment with the test substance.

Other findings:

Mean food intake was statistically significantly decreased far both sexes in the 343 mg/kg group after 4 days of treatment when comparing with the control group. This was considered to be an adverse effect of administration of ammonium thiocyanate. Due to death of the birds, non-relevant statistical significant differences were obtained for the higher dose groups. No effect on mean food consumption was seen at 191 mg/kg.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Migrated information

Conclusions:

Under the conditions of this study, the oral LD values of ammoniumthiocyanate in Japanese quail for the sexes combined was established as 508
mg/kg body weight with 95% confidence limits being 349 - 693 mg/kg and the slope of the dose-response curve 3.11. For the individual sexes the LD50 values were also established to be 508 mg/kg body weight with the 95% confidence intervals being 285 - 790 mg/kg and the slope being 2.45. The no observed effect level (NOEL) in this study was 191 mg/kg body weight.

Executive summary:

This study was performed to assess the acute thiocyanate to the Japanese quail when administered as a single oral dose. The study carried out was based on the OECD Guideline No. 401 and on the EPA FIFRA Ref. No. 71-1, EPA TSCA Par. 797.2175, EPA OPPTS Par. 850.2100 Guidelines, with the exception that the study was performed with Japanese quails.

Treatment

Ammonium thiocyanate was administered by oral gavage, using water (Milli-U) as a vehicle, to five birds of each sex at 191, 343, 617, 1111 or 2000 mg/kg body weight. A control group of five birds of each sex was dosed with vehicle (5 ml/kg). Birds were observed at periodic intervals on the day of dosing and daily thereafter; body weight was determined at start of the study (day 1), day 8 and day 15; food consumption was measured from days 1-4, 4-8, 8-11 and 11-15. Macroscopic post-mortem examination was performed at termination (day 15).

Results

0 mg/kg: 1) Fluid faeces.

191 mg/kg: 1) Fluid faeces.

343 mg/kg: 1) Fluid faeces, uncoordinated movements, lethargy, clonic spasms, abnormal posture of the head, ventro-lateral recumbency, hunched posture, breathing abnormalities or ptosis were seen among the birds.

2) Reduced food consumption during 4 days after dosing.

1111 mg/kg 1) All birds died within 5 hours after dosing, except for one male which was found dead on day 2. 2 )Clinical signs noted were fluid or red faeces, uncoordinated movements, lethargy, clonic spasms, abnormal posture of the head, tremors of the head or wing, ventro-lateral recumbency, hunched posture, breathing abnormalities and ptosis. 3) Examination post-mortem revealed haemorrhages in the intestines, swollen andlor dark red liver, dark red spleen and a detached cuticle of the stomach.

2000 mg/kg

1) All birds died within 1 hour post-dosing.

2) Clinical signs noted were fluid faeces, uncoordinated movements, lethargy, clonit spasms, tremors or abnormal posture of the head, ventro-lateral recumbency, hunched posture, breathing abnormalities and ptosis.

3) Examination post-mortem revealed haemorrhages in the intestines, swollen andlor dark red liver and detached cuticles of the stomach.

Conclusion

Under the conditions of this study, the oral LD50 values of ammonium thiocyanate in Japanese quail was established as 508 mg/kg body weight with 95% confidence limits being 349 - 693 mg/kg and the slope of the dose-response curve 3.11. For the individual sexes the LD50 values were also established to be 508 mg/kg body weight with the 95% confidence intervals being 285 - 790 mg/kg and the slope being 2.45. The no observed effect level (NOEL) in this study was 191 mg/kg body weight.