Terephthalaldehyde

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Terephthalaldehyde

EC Number:

210-784-8

EC Name:

Terephthalaldehyde

Cas Number:

623-27-8

Molecular formula:

C8H6O2

IUPAC Name:

benzene-1,4-dicarbaldehyde

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Batch (Lot) Number: 180401
Expiry date: 01 April 2020 (retest date)
Physical Description: Light yellow powder
Purity/Composition: 99.6%
Storage Conditions: At room temperature

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Crl: WI (Han)

Sex:

female

Details on test animals or test system and environmental conditions:

Species: Rat
Strain: Crl: WI(Han)
Condition: Outbred, SPF-Quality
Source: Charles River Deutschland, Sulzfeld, Germany
Number of Animals: 6 Females (nulliparous and non-pregnant). Each dose group consisted of 3 animals.
Age at the Initiation of Dosing: Young adult animals (approximately 8 and 12 weeks old) were selected.
Weight at the Initiation of Dosing: 138 to 213 g.

At study assignment, each animal was identified using an ear mark and tail mark with indelible ink.

Environmental Acclimation
The animals were allowed to acclimate to the Test Facility toxicology accommodation for at least 5 days before the commencement of dosing.

Selection, Assignment, Replacement, and Disposition of Animals
Animals were assigned to the study at the discretion of the coordinating biotechnician according to body weights, with all animals within ± 20% of the sex mean. Animals in poor health or at extremes of body weight range were not assigned to the study.
Before the initiation of dosing, a health inspection was performed and any assigned animal considered unsuitable for use in the study were replaced by alternate animals obtained from the same shipment and maintained under the same environmental conditions.
The disposition of all animals was documented in the study records.

Husbandry
Housing
On arrival and following assignment to the study, animals were group housed (up to 3 animals of the same sex and same dosing group together) in polycarbonate cages (Makrolon MIV type; height 18 cm.) containing sterilized sawdust as bedding material (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne GmbH + CO. KG, Rosenberg, Germany) equipped with water bottles. The room in which the animals were kept was documented in the study records.
Animals were separated during designated procedures/activities. Each cage was clearly labeled.

Environmental Conditions
Target temperatures of 18 to 24°C with a relative target humidity of 40 to 70% were maintained. The actual daily mean temperature during the study period was 21°C with an actual daily mean relative humidity of 37 to 59% (see deviations in Appendix 3). A 12 hour light/12 hour dark cycle was maintained. Ten or greater air changes per hour with 100% fresh air (no air recirculation) were maintained in the animal rooms.

Food
Pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany) was provided ad libitum throughout the study, except during designated procedures.
The feed was analyzed by the supplier for nutritional components and environmental contaminants. Results of the analysis were provided by the supplier and are on file at the Test Facility.
It is considered that there were no known contaminants in the feed that would interfere with the objectives of the study.

Water
Municipal tap-water was freely available to each animal via water bottles.
Periodic analysis of the water was performed, and results of these analyses are on file at the Test Facility.
It is considered that there were no known contaminants in the water that would interfere with the objectives of the study.

Animal Enrichment
For psychological/environmental enrichment, animals were provided with paper (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom), except when interrupted by study procedures/activities.

Veterinary Care
Veterinary care was available throughout the course of the study; however, no examinations or treatments were required.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Remarks:

mw 400

Details on oral exposure:

Rationale for Vehicle
Trial preparations were performed at the Test Facility to select the suitable vehicle and to establish a suitable formulation procedure. Trial preparation formulations were not used for dosing and were discarded after the assessment is complete. These trial preparations have a non-GLP status and were carried out in the quality assured environment of the Test Facility.

Preparation of Test Item
Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements.
The dosing formulations were kept at room temperature until dosing. The dosing formulations were stirred until and during dosing.
Adjustment was made for specific gravity of the vehicle. No correction was made for the purity/composition of the test item.
Any residual volumes were discarded.

Administration of Test item
A single dose of test item was administered to the appropriate animals by oral gavage on Day 1, using a syringe with a plastic gavage cannula attached.
The dose volume for each animal was based on the body weight measurement prior to dosing. A dose volume of 10 mL/kg body weight was used for each dose.
The dosing formulations were stirred continuously during dose administration.
Animals were deprived of food overnight (for a maximum of 20 hours) prior to dosing and until 3-4 hours after administration of the test item. Water was available.

Justification of Route and Dose Levels
The oral route was selected as it is a possible route of human exposure during manufacture, handling or use of the test item.
The dose levels were based on the OECD test guidelines and were selected from the series 5 (lowest dose level), 50, 300 and 2000 (highest dose level) mg/kg body weight. The starting dose level should be the one that is likely to produce mortality in at least some of the animals and was selected based on available toxicity data of the test item.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

three females

Control animals:

no

Details on study design:

Mortality/Moribundity Checks
Throughout the study, animals were observed for general health/mortality and moribundity twice daily, in the morning and at the end of the working day. Animals were not removed from cage during observation, unless necessary for identification or confirmation of possible findings.

Clinical Observations
Postdose Observations
Postdose observations were performed at periodic intervals on the day of dosing (at least three times) and once daily thereafter. The observation period was 14 days.
All the animals were examined for reaction to dosing. The onset, intensity and duration of these signs was recorded (if appropriate). Signs were graded for severity and the maximum grade was predefined at 3 or 4. Grades were coded as slight (grade 1), moderate (grade 2), severe (grade 3) and very severe (grade 4). For certain signs, only its presence (grade 1) or absence (grade 0) was scored.

Body Weights
Animals were weighed individually on Day 1 (predose), 8 and 15. A fasted weight was recorded on the day of dosing.

Terminal Procedures
All animals were sacrificed by oxygen/carbon dioxide procedure at the end of the observation period. All animals assigned to the study were subjected to necropsy and descriptions of all internal macroscopic abnormalities were recorded.

Statistics:

No statistical analysis was performed (The method used is not intended to allow the calculation of a precise LD50 value).

Results and discussion

Preliminary study:

N/A

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LD50 cut-off

Effect level:

>= 5 000 mg/kg bw

Based on:

test mat.

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Hunched posture, uncoordinated movements and/or piloerection were noted for the animals on Day 1.

Gross pathology:

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

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 value of Terephthaldehyde in Wistar Han rats was established to exceed 2000 mg/kg body weight.
According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight.
Based on these results, Terephthaldehyde does not have to be classified and has no obligatory labelling requirement for acute oral toxicity according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).

Executive summary:

The objective of this study was todetermine the potential toxicity of Terephthaldehyde, when given by oral gavage at a single dose to rats of a single sex at one or more defined doses to evaluate the potential reversibility of any findings.

 

The study was carried out in compliance with the guidelines described in:

·        OECD No.423 (2001) "Acute Oral Toxicity, Acute Toxic Class Method"

·        EC No 440/2008, part B: "Acute Oral Toxicity, Acute Toxic Class Method"

·        EPA, OPPTS 870.1100 (2002), "Acute Oral Toxicity"

·        JMAFF Guidelines (2000), including the most recent revisions.

 

Terephthaldehyde was administered by oral gavage to two consecutive groups of three female Wistar Han rats at 2000 mg/kg body weight. Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice (Day 15).

 

No mortality occurred.

Hunched posture, uncoordinated movements and/or piloerection were noted for the animals on Day 1.

The body weight gain shown by the animals over the study period was considered to be similar to that expected for normal untreated animals of the same age and strain.

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

 

The oral LD50value of Terephthaldehyde in Wistar Han rats was established to exceed 2000 mg/kg body weight.

According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight.

Based on these results, Terephthaldehyde does not have to be classified and has no obligatory labelling requirement for acute oral toxicity according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).