3,4-dihydroxybenzonitrile

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 November - 28 December 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2001

Deviations:

yes

Remarks:

Deviations from the minimum level of daily mean relative humidity occurred on two days (39.67 and 38.65%). Evaluation: Laboratory historical data do not indicate an effect of the deviations.

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May 2008, including the most recent amendments

Deviations:

yes

Remarks:

Deviations from the minimum level of daily mean relative humidity occurred on two days (39.67 and 38.65%). Evaluation: Laboratory historical data do not indicate an effect of the deviations.

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

2002

Deviations:

yes

Remarks:

Deviations from the minimum level of daily mean relative humidity occurred on two days (39.67 and 38.65%). Evaluation: Laboratory historical data do not indicate an effect of the deviations.

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: JMAFF Notification No 8147

Version / remarks:

November 2000, including the most recent parital revisions

Deviations:

yes

Remarks:

Deviations from the minimum level of daily mean relative humidity occurred on two days (39.67 and 38.65%). Evaluation: Laboratory historical data do not indicate an effect of the deviations.

GLP compliance:

yes

Test type:

acute toxic class method

Test material

Test material information

Constituent 1

Reference substance name:

3,4-dihydroxybenzonitrile

EC Number:

241-367-9

EC Name:

3,4-dihydroxybenzonitrile

Cas Number:

17345-61-8

Molecular formula:

C7H5NO2

IUPAC Name:

3,4-dihydroxybenzonitrile

Test material form:

solid: particulate/powder

Remarks:

white to brownish

Details on test material:

Batch 151222

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI (Han) (outbred, SPF-Quality)

Sex:

female

Details on test animals or test system and environmental conditions:

Animal Husbandry
Conditions
Environmental controls for the animal room were set to maintain 18 to 24°C (actual range 20.1 – 20.8 °C), a relative humidity of 40 to 70% (actual range 39 – 48%), at least 10 air changes/hour, and a 12-hour light/12-hour dark cycle. Any variations to these conditions were maintained in the raw data and had no effect on the outcome of the study.
Accommodation
Group housing of 3 animals per cage in labeled Makrolon cages (MIV type; height 18 cm.) containing sterilized sawdust as bedding material (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne GmbH + CO. KG, Rosenberg, Germany) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom).
Acclimatization period was at least 5 days before start of treatment under laboratory conditions.
Diet
Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
Water
Free access to tap water.
Diet, water, bedding and cage enrichment evaluation for contaminants and/or nutrients was performed according to facility standard procedures. There were no findings that could interfere with the study.

Age and body weight
Young adult animals (approx. 8-9 weeks old) were selected. Body weight variation did not exceed +/- 20% of the sex mean.
Identification
Earmark and tail mark
Health inspection
At least prior to dosing. It was ensured that the animals were healthy and without any abnormality that might have affected the study integrity.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on oral exposure:

The vehicle was selected based on trial preparations performed at Charles River Den Bosch and on test item data supplied by the Sponsor. There was no information available regarding the solubility or stability in vehicle.

The preparations (w/w) were kept at room temperature and were dosed within 4 hours after adding the vehicle to the test item. Homogeneity was assessed by visual inspection of the solutions and the formulations were stirred during dosing, which ensures homogeneity sufficient for these kinds of studies. Adjustment was made for specific gravity of the vehicle. No correction was made for purity of the test item. The concentration of the test item in vehicle was varied to allow constant dosage volume in terms of mL/kg body weight. In order to obtain homogeneity, the test item (preparations) were stirred for 15 minutes.

Oral gavage, using plastic feeding tubes. The test item preparations were stirred on a magnetic stirrer during dosing.
10 mL/kg b.w. for each dose.
Animals were deprived of food overnight prior to dosing and until 3-4 hours after administration of the test item. Water was available ad libitum.

Single dosage on Day 1.

Doses:

2000 mg/kg (10 mL/kg) body weight.
300 mg/kg (10 mL/kg) body weight.
50 mg/kg (10 mL/kg) body weight.

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

Mortality/Viability
Twice daily. The time of death was recorded as precisely as possible.
Body weights
Days 1 (pre-administration), 8 and 15.
Clinical signs
At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15. The signs were graded according to fixed scales and the time of onset, degree and duration were recorded:
Maximum grade 4: grading slight (1) to very severe (4) Maximum grade 3: grading slight (1) to severe (3)
Maximum grade 1: presence is scored (1).
Necropsy
Animals surviving to the end of the observation period were sacrificed by oxygen/carbon dioxide procedure. All animals assigned to the study were subjected to necropsy and descriptions of all internal macroscopic abnormalities recorded.

Statistics:

/

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 50 - <= 300 mg/kg bw

Based on:

test mat.

Effect levels 2

Key result

Sex:

female

Dose descriptor:

LD50 cut-off

Remarks:

Based on OECD 423 test guideline

Effect level:

200 mg/kg bw

Based on:

test mat.

Mortality:

At 2000 and 300 mg/kg all animals were found dead on Day 1 post-treatment.

Clinical signs:

other: At 2000 mg/kg, no clinical signs were noted. At 300 mg/kg, hunched posture was noted for all animals on Day 1. At 50 mg/kg, hunched posture, uncoordinated movements and/or piloerection were noted for all animals on Day 1. The surviving animals had recover

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The oral LD50 value of CH02906 in Wistar rats was established 50-300 mg/kg body weight.
According to the OECD 423 test guideline, the LD50 cut-off value was considered to be 200 mg/kg body weight.

Based on these results:
• according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments), CH02906 should be classified as: Toxic if swallowed (Category 3) for acute toxicity by the oral route.
• according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments), CH02906 should be classified as Category 3 and should be labeled as H301: Toxic if swallowed.