1,3-phenylenebis((4-hydroxyphenyl)methanone)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because skin contact in production and/or use is not likely

the study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and no systemic effects have been observed in in vivo studies with dermal exposure (e.g. skin irritation, skin sensitisation)

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 August 2017 - 14 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

December 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

December 2002

Qualifier:

according to guideline

Guideline:

other: EC No 440/2008 Part B. Acute Oral Toxicity, Acute Toxic Class Method

Version / remarks:

May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: JMAFF Guidelines, Appendix to Director General Notification, No. 12-Nousan-8147, including the most recent revisions.

Version / remarks:

November 2000

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

- Identification: 1,3-Bis (4-hydroxy benzoyl) benzene
- Appearance: Off white crystalline powder
- Test item storage: At room temperature
- Stable under storage conditions until: 15 May 2018 (expiry date)

Species:

rat

Strain:

Wistar

Remarks:

(Han)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: approximately 8-9 weeks old
- Weight at study initiation: 155 to 177 g
- Fasting period before study: 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.
- Housing: animals were group housed (up to 5 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
- Diet (e.g. ad libitum): Pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany), ad libitum except during designated procedures
- Water (e.g. ad libitum): Municipal tap-water via water bottles, ad libitum
- Acclimation period: at least 5 days before the commencement of dosing

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 24°C
- Humidity (%): 46 - 67%
- Air changes (per hr): Ten or greater air changes per hour with 100% fresh air (no air recirculation)
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark

IN-LIFE DATES: From: 02 September 2017 To: 27 September 2017

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

1% Aqueous carboxymethyl cellulose

Details on oral exposure:

VEHICLE
- Amount of vehicle (if gavage): 10 mL/kg bw
- Justification for choice of vehicle: The vehicle and formulation procedure were selected based on trial preparations performed at Charles River Den Bosch and on test item data supplied by the Sponsor. The vehicle was chosen from (in order of preference): water (Elix), 1% aq. carboxymethyl cellulose, propylene glycol, polyethylene glycol 400 and corn oil. Without heating of the formulations, no homogenous dosing formulations could be obtained using the vehicle as mentioned above. Water did not provide a homogenous formulation at all while the other vehicle provided clear to cloudy solutions. Based on the results, 1% aq. carboxymethyl cellulose was selected as suitable vehicle.

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg bw

DOSAGE PREPARATION: Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements. In order to obtain homogeneity, the test item formulations were heated in a water bath with a maximum temperature of 61.6ºC for a maximum of 48 minutes. The test item formulations were allowed to cool to a temperature of maximally 40ºC. Then the dosing formulations were kept at room temperature until dosing. The dosing formulations were stirred until and during dosing.
No adjustment was made for specific gravity of the vehicle. No correction was made for the purity/composition of the test item.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: 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:

A single dose of test item: 2000 mg/kg bw

No. of animals per sex per dose:

3 per step

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
- Mortality/Morbundity checks: twice daily, in the morning and at the end of the working day.
- Postdose observations: on the day of dosing (at least three times) and once daily thereafter.
- Body weights: weighed individually on Day 1 (predose), 8 and 15. A fasted weight was recorded on the day of dosing.
- Necropsy of survivors performed: yes, by oxygen/carbon dioxide procedure.
- Other examinations performed: clinical signs, body weight, other: internal macroscopic exmination

Statistics:

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

Preliminary study:

None

Key result

Sex:

female

Dose descriptor:

LD50

Remarks:

(oral)

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Sex:

female

Dose descriptor:

LD50

Remarks:

(cut-off)

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

Hunched posture and piloerection were noted for three animals of the first group on Day 1.

Body weight:

The mean 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.
The incidence of slight body weight loss between Days 8 and 15 in one animal of the second group (Day 8: 180 g and Day 15: 179 g) was considered not indicative of toxicity, based on the absence of any corroborative findings in this animal.

Gross pathology:

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

Other findings:

None

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, the oral LD50 value of 1,3-Bis (4-hydroxy benzoyl) benzene in female Wistar 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.

Executive summary:

This Acute Toxicity study evaluated the potential toxicity of 1,3-Bis (4-hydroxy benzoyl) benzene, when given by oral gavage at a single dose of 2000 mg/kg bw to femùale Wistar rats, and the potential reversibility of any findings. The study was carried out in accordance with the OECD No.423 guideline (Acute Oral Toxicity, Acute Toxic Class Method), EC Directive No 440/2008 (part B: "Acute Oral Toxicity, Acute Toxic Class Method"), OPPTS 870.1100 EPA guideline (Acute Oral Toxicity) and JMAFF Guidelines and in compliance with GLP.

The test substance was administered by oral gavage to two consecutive groups of three female Wistar 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 and piloerection were noted for three animals of the first group on Day 1. The mean 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. The incidence of slight body weight loss between Days 8 and 15 after dosing in one animal of the second group was considered not indicative of toxicity, based on the absence of any corroborative findings in this animal. No abnormalities were found at macroscopic post mortem examination of the animals.

Under the test conditions, the oral LD50 value of 1,3-Bis (4-hydroxy benzoyl) benzene in female Wistar rats was established to exceed 2000 mg/kg body weight and, 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, 1,3-Bis (4-hydroxy benzoyl) benzene 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).

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 January 2018 - 30 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The results obtained from the available in silico/in chemico/in vitro studies are not adequate for classification and risk assessment.

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

July 2010

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EC No 640/2012, Part B: Skin sensitization: "Local Lymph Node Assay"

Version / remarks:

July 2012

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

March 2003

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Specific details on test material used for the study:

- Appearance: Off white crystalline powder
- Test item storage: At room temperature
- Stable under storage conditions until: 15 May 2018 (expiry date)

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Details on test animals and environmental conditions:

- Source: Janvier, Le Genest-Saint-Isle, France
- Age at study initiation: Young adult animals (approx. 10 weeks old)
- Weight at study initiation: 19.2 - 22.9 g
- Housing: Animals were group housed (up to 5 animals together) in labeled Makrolon cages containing sterilized sawdust as bedding material.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS (daily mean)
- Temperature (°C): 22 - 23
- Humidity (%): 41 - 43
- Air changes (per hr): 10 or greater
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 10 January 2018 - 5 February 2018

Vehicle:

dimethylformamide

Concentration:

0, 10, 25, 60% (w/w) (main study)
25, 60% (w/w) (pre-test)

No. of animals per dose:

5 (main study)
2 (pre-test)

Details on study design:

RANGE FINDING TESTS:
Two test item concentrations were tested: a 25% and 60% concentration. The highest concentration was the maximum concentration as required in the test guidelines.
The test system, procedures and techniques were identical to those used in the main study except that the assessment of lymph node proliferation and necropsy were not performed. Two young adult animals per concentration were selected. Each animal was treated with one concentration on three consecutive days. Animals were group housed in labeled Makrolon cages (MII type, height 14 cm). Ear thickness measurements were conducted using a digital thickness gauge (prior to dosing on days 1 and 3, and on day 6.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay
- Criteria used to consider a positive response: DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group using the individual SI values. The individual SI is the ratio of the DPM/animal compared to DPM/vehicle control group mean. If the results indicate a SI ≥ 3, the test substance may be regarded as a skin sensitizer, based on the test guideline and recommendations done by ICCVAM.

ANIMAL ASSIGNMENT
Three groups of five animals were treated with one test substance concentration per group. One group of five animals was treated with vehicle.

TREATMENT PREPARATION AND ADMINISTRATION:
Test substance preparation: Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements. The dosing formulations were prepared daily and dosed within 4 hours after adding the vehicle to the test item and were kept at room temperature until dosing. The dosing formulations were stirred until and during dosing. No adjustment was made for specific gravity of the vehicle and no correction was made for the purity/composition of the test item, since the test method requires a logical concentration range rather than specific dose levels.

Rationale for vehicle: The vehicle was chosen from the vehicles specified in the test guideline. The vehicle was selected on the basis of maximizing the solubility based on trial preparations performed at Charles River Den Bosch and on information provided by the Sponsor.


Induction - Days 1, 2 and 3; Excision of nodes - Day 6; Tissue processing for radioacitivity - Day 6; Radioactivity measurements - Day 7; Performed according to test guidelines.


Observations:
Mortality/Viability: Twice daily.
Body weights: On day 1 (pre-dose) and day 6 (prior to necropsy).
Clinical signs: Once daily on days 1-6 (on days 1-3 between 3 and 4 hours after dosing).
Irritation: Once daily on days 1-6 (on days 1 - 3 within 1 hour after dosing) according to a numerical scoring system (according to guideline). Furthermore, a description of all other (local) effects was recorded according to guidelines.

Necropsy: No necropsy was performed, since all animals survived until the end of the observation period.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Not performed.

Positive control results:

The six-month reliability check with Alpha-hexylcinnamaldehyde indicates that the Local Lymph Node Assay as performed at Charles River Den Bosch is an appropriate model for testing for contact hypersensitivity.

Key result

Parameter:

SI

Value:

0.8

Variability:

0.0 (standard error of the mean)

Test group / Remarks:

10%

Remarks on result:

other: Since there was no indication that the test item elicits a SI ≥ 3 when tested up to 60%, the substance was not considered to be a skin sensitizer

Key result

Parameter:

SI

Value:

0.8

Variability:

0.1 (standard error of the mean)

Test group / Remarks:

25%

Remarks on result:

other: Since there was no indication that the test item elicits a SI ≥ 3 when tested up to 60%, the substance was not considered to be a skin sensitizer

Key result

Parameter:

SI

Value:

0.8

Variability:

0.1 (standard error of the mean)

Test group / Remarks:

60%

Remarks on result:

other: Since there was no indication that the test item elicits a SI ≥ 3 when tested up to 60%, the substance was not considered to be a skin sensitizer

Cellular proliferation data / Observations:

Mean DPM/animal values for the experimental groups treated with test item concentrations 10, 25 and 60% were 836, 830 and 828 DPM, respectively. The mean DPM/animal value for the vehicle control group was 1055 DPM. The SI values calculated for the test item concentrations 10, 25 and 60% were 0.8, 0.8 and 0.8, respectively.

Results Pre-screen test:

At a 25% and 60% test item concentration, no signs of systemic toxicity were noted and no irritation was observed and therefore the 60% concentration was selected as highest concentration for the main study.

Other results - main study:

Skin Reactions / Irritation

No irritation was observed in any of the animals. White test item remnants were present on the dorsal surface of the ears of all test item treated animals throughout the observation period, which did not hamper scoring of the skin reactions

Macroscopic  Examination of the Lymph Nodes and Surrounding Area

All auricular lymph nodes of the animals of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted for any of the animals.

Systemic Toxicity and bodyweight

No mortality occurred and no clinical signs of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

Interpretation of results:

GHS criteria not met

Conclusions:

In an LLNA skin sensitisation study, performed according to OECD/EC test guidelines and in compliance with GLP principles, 1,3-Bis (4-hydroxy benzoyl) benzene was considered not to be a skin sensitiser, as the SI appeared not to be ≥ 3 when tested up to 60% (w/w).

Executive summary:

An LLNA skin sensitisation study was performed according to OECD/EC test guidelines and GLP principles. Based on the results of a pre-screen test, the test concentrations were selected at 10%, 25% and 60% w/w. No irritation was observed in any of the animals. All auricular lymph nodes were considered normal in size. No macroscopic abnormalities of the surrounding area were noted for any of the animals. No mortality occurred and no clinical signs of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period. Mean DPM/animal values for the experimental groups treated with test item concentrations 10, 25 and 60% were 836, 830 and 828 DPM, respectively. The mean DPM/animal value for the vehicle control group was 1055 DPM. The SI values calculated for the test item concentrations 10, 25 and 60% were 0.8, 0.8 and 0.8, respectively. As the SI appeared not to be ≥ 3 when tested up to 60% w/w, 1,3 -Bis (4-hydroxy benzoyl) benzene was not considered to be a skin sensitiser.