p-phenylene diisocyanate

Endpoint summary

Description of key information

The Oral LD50 value of is 5000 mg/kg body weight.

The dermal LD50 value of PPDI was established to exceed 2000 mg/kg body weight.

LC50 could not be established due to the large, non-respirable particulate formed at high concentrations

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

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)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Source: In-Vivo Biosciences
Kodigehalli Village
Magadi Road, Bangalore, Code-29
Karnataka State

Age. 9 to 11 weeks

After physical examination for good health and suitability for experiment, the animals were acclimatized six days for G1-FTS and eight days for G1-STS before treatment. Animals were observed once daily during acclimatization period. Females were nulliparous and non-pregnant.

Rats were housed under standard laboratory conditions, air conditioned with adequate fresh air supply (13.7 air changes/hour). Environment: with temperature 20 to 23°C, relative humidity 64 to 66%, with 12 hours light and 12 hours dark cycle. The maximum and minimum temperature and relative humidity in the experimental room were recorded once daily. The relative humidity in the experimental room was calculated from dry and wet bulb temperature recordings.

Rat & Mice pellet feed, manufactured by Krishna Valley Agro Tech LLP, MIDC Kupwad block, Sangli, Maharashtra, was provided to animals.

Deep bore-well water passed through activated charcoal filter and exposed to UV rays in Aquaguard on-line water filter-cum-purifier manufactured by Eureka Forbes Ltd, Mumbai 400 001, India, was provided to animals in polycarbonate bottles with stainless steel sipper tubes.

Route of administration:

oral: gavage

Vehicle:

other: 0.5% w/v NaCMC with 0.1% v/v Tween 80 in MIlli-Q water

Details on oral exposure:

The prepared test item dose formulation was administered at the dose volume of 10 mL/kg bodyweight to attain the dose of 2000 mg/kg body weight (G1 – First and second treatment steps) as a single oral gavage to overnight fasted rats (16 to 18 hours). Each animal was administered orally by gavage using disposable plastic syringe attached with metal feeding cannula. Food was offered about 3 to 4 hours after dosing. Water was not withheld.

Doses:

As per the public available data (MSDS) provided by the sponsor, the acute oral toxicity LD50 of PPDI for rats is 2160 mg/kg. Hence, the study was initiated with the starting dose of 2000 mg/kg body weight (G1-FTS). The test was started as per Annex 2d of the OECD 423 test guideline.

No. of animals per sex per dose:

First treatment group: three
Second treatment group: three

Control animals:

no

Details on study design:

At each step, the animals were observed five times on test day 1 (day of administration) i.e. at 30 minutes and four times at hourly intervals and once daily during days 2 to 15 post administration.
Observations included changes in skin and fur, eyes and mucous membranes, and also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern. Attention was directed to the observations of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma and all observed clinical signs were recorded.
The body weights were recorded on test day 1 (pre-administration), day 8 (7 days post administration) and day 15 (14 days post administration).The rats surviving to the end of the observation period were euthanised by
using isoflurane anaesthesia and subjected to detailed necropsy. Gross pathological findings were recorded and reported. Microscopic examination was not carried out as no gross pathological changes were observed.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

5 000 mg/kg bw

Based on:

test mat.

Mortality:

No pre-terminal deaths.

Clinical signs:

other: No clinical signs.

Gross pathology:

No abnormalities detected.

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of the present study, the test item, P-phenylene diisocyanate, The LD50 is 5000 mg/kg body weight or Unclassified as per LD50 cut-off value.

Executive summary:

The acute oral toxicity study with P-phenylene diisocyanate in Wistar rats was conducted to assess the toxicological profile of the test item. The dose formulation was prepared by using 0.5% w/v Sodium carboxy methyl cellulose (medium viscosity) with 0.1% v/v Tween in Milli-Q water and administered as a single oral gavage to overnight fasted (16 to 18 hours) three female rats (G1-FTS) at the dose of 2000 mg/kg body weight. There were no clinical signs of toxicity and pre-terminal deaths. Based on the scheme - Annex

2d of the guideline OECD 423, three additional female rats were tested at the same dose of 2000 mg/kg body weight (G1-STS). There were no clinical signs of toxicity and pre-terminal deaths. Based on the scheme - Annex 2d of the guideline OECD 423, the dose was stopped The rats were observed for mortality and clinical signs for 14 days post

treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Necropsy was performed for all the rats at termination. All survived rats gained weight during experimental period. There were no gross pathological changes at necropsy. Based on the results of the present study, the test item, P-phenylene diisocyanate, The LD50 is 5000 mg/kg body weight or Unclassified as per LD50 cut-off value.

The test item, P-phenylene diisocyanate is classified as follows:

• The test item is classified “Category 5” or Unclassified as per Globally Harmonized Classification system of Annex 2d of the Guideline, OECD 423.
• The test item does not meet the criteria for classification as “Category 4” (300 mg/kg < Acute Toxicity Estimates ≤ 2000 mg/kg) as per Regulation (EC) No 1272/2008 of the European Parliament and of the council of 16 December 2008 on classification, labeling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006, as there was no mortality observed at 2000 mg/kg body weight.

• The test item is classified as “Category 5” (the oral LD50 range of 2000 to 5000 mg/kg) as per OECD: Harmonised Integrated Classification system (OECD, 2001), as there was no mortality observed at 2000 mg/kg body weight.
• The test item is classified as “Category 5 or unclassified” (oral LD50 in the range of 2000 to 5000 mg/kg) as per Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Seventh Revised Edition, United Nations (2017). ST/SG/AC.10/30/Rev.7, as there was no mortality observed at 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because exposure of humans via inhalation is not likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

335 mg/m³ air

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:

11 Jun 2018 to 09 Jul 2018.

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:

OECD Guideline 402. Acute Dermal Toxicity, 2017.

Deviations:

yes

Remarks:

See "Any other information" for details

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Specific details on test material used for the study:

No further details specified in the study report.

Species:

rat

Strain:

Wistar

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: 3 females (nulliparous and non-pregnant).
Age at the Initiation of Dosing: Young adult animals (approximately 11 weeks old) were selected.
Weight at the Initiation of Dosing: 183 to 194 g.

Justification for Test System and Number of Animals
The Wistar Han rat was chosen as the animal model for this study as recognized by international guidelines as a recommended test system. The test method and number of animals were based on the test guidelines.
The study plan was reviewed and agreed by the Animal Welfare Body of Charles River Laboratories Den Bosch B.V. within the framework of Appendix 1 of project license AVD2360020172866 approved by the Central Authority for Scientific Procedures on Animals (CCD) as required by the Dutch Act on Animal Experimentation (December 2014).

Animal Identification
At study assignment, each animal was identified using a 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, animals were group housed (up to 5 animals of the same sex together) in polycarbonate cages (Makrolon MIV type; height 18 cm.) and following assignment to the study, animals were individually housed in polycarbonate cages (Makrolon MIII 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 to 22°C with an actual daily mean relative humidity of 32 to 70%. 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.

Type of coverage:

occlusive

Vehicle:

peanut oil

Details on dermal exposure:

A single dose of test item was administered to the appropriate animals by dermal application on Day 1. One day before dosing, an area of approximately 5x7 cm on the back of the animals was clipped. The test item was applied in an area of approximately 10% of the total body surface, i.e. approximately 18 cm² for females. The test item was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D), successively covered with Coban elastic bandage. A piece of Micropore tape was additionally used for fixation of the bandages in females only. The application period was 24 hours, after which the dressing was removed and the skin cleaned of residual test item using water.
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 will be used for each dose.
The dosing formulations were stirred continuously during dose administration.

Duration of exposure:

24 hours

Doses:

Single dose 2000 mg/kg

No. of animals per sex per dose:

Rnage finding study: 1 animal
Main study: 2 animals

Control animals:

not required

Details on study design:

In-life Procedures, Observations, and Measurements
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), particular attention being paid to the animals during and for the first hour after dosing.

Body Weights
Animals were weighed individually on Day 1 (predose), 8 and 15.

Irritation
The skin reactions were assessed approximately 24, 48 and 72 hours after the removal of the dressing and test item. Adjacent areas of untreated skin of each animal served as controls.

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:

All results presented in the tables of the report are calculated using values as per the raw data rounding procedure and may not be exactly reproduced from the individual data presented.
The dermal LD50 value of the test item was ranked within the following ranges: 0-50, 50-200, 200-1000 or 1000-2000 mg/kg b.w. or as exceeding 2000 mg/kg b.w.

Key result

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, shallow respiration, piloerection and/or chromodacryorrhoea of the snout were noted for the animals between Days 1 and 4.

Gross pathology:

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

Other findings:

Irritation
Very slight to well-defined erythema, fissures, scales, scabs and white discoloration were noted for the treated skin area of the animals between Days 2 and 15.

MORTALITY DATA

TEST DAY	1	1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
HOURS AFTER TREATMENT	0	2	4
FEMALES 2000 MG/KG FEMALES 2000 MG/KG	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -	- -

 

CLINICAL SIGNS

TEST DAY		1	1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
HOURS AFTER TREATMENT	MAX GRADE	0	2	4
FEMALES 2000 MG/KG
ANIMAL 1 Skin / fur            General erythema (Treated skin)            Fissures (Treated skin)            Scales (Treated skin) Secretion / excretion            Chromodacryorrhoea (Snout)	(4) (3) (3)   (3)	- - -   -	- - -   1	- - -   -	- - -   -	1 - 1   -	1 - 1   -	1 1 1   -	1 1 1   -	1 1 1   -	1 - 2   -	1 - 1   -	1 - 1   -	1 - 1   -	1 - 1   -	. . .   .	. . .   .	- - 1   -
FEMALES 2000 MG/KG
ANIMAL 2 Posture            Hunched posture Breathing            Shallow respiration Skin / fur            General erythema (Treated skin)            Piloerection            Scales (Treated skin)            Scabs (Treated skin) Various            White (Treated skin)	(1)   (3)   (4) (1) (3) (3)   (1)	-   -   - - - -   -	-   -   - - - -   -	-   -   - - - -   -	1   1   2 1 1 -   1	1   -   2 - 1 -   1	1   -   2 - 1 -   1	-   -   2 - 1 -   1	-   -   2 - 1 -   1	-   -   1 - 1 1   -	-   -   1 - 1 1   -	-   -   1 - 1 1   -	-   -   - - - 1   -	-   -   - - - 1   -	-   -   - - - -   -	-   -   - - - -   -	-   -   - - - -   -	-   -   - - - -   -
ANIMAL 3 Posture            Hunched posture Breathing            Shallow respiration Skin / fur            General erythema (Treated skin)            Piloerection            Scales (Treated skin) Secretion / excretion            Chromodacryorrhoea (Snout) Various            White (Treated skin)	(1)   (3)   (4) (1) (3)   (3)   (1)	-   -   - - -   1   -	-   -   - - -   1   -	-   -   - - -   1   -	1   1   2 1 -   -   1	-   -   1 - -   -   1	-   -   1 - 1   -   1	-   -   1 - 1   -   1	-   -   1 - 1   -   1	-   -   - - 1   -   -	-   -   - - 1   -   -	-   -   - - 1   -   -	-   -   - - 1   -   -	-   -   - - -   -   -	-   -   - - -   -   -	-   -   - - -   -   -	-   -   - - -   -   -	-   -   - - -   -   -

- = Sign not observed

. = No observation recorded

 

BODY WEIGHTS (GRAM)

SEX/DOSE LEVEL	ANIMAL	DAY 1	DAY 8	DAY 15
FEMALES 2000 MG/KG
	1   MEAN ST. DEV. N	194   194 --- 1	203   203 --- 1	212   212 --- 1
FEMALE 2000 MG/KG
	2 3   MEAN ST. DEV. N	183 188   186 4 2	199 195   197 3 2	210 207   209 2 2

 

MACROSCOPIC FINDINGS

ANIMAL	ORGAN	FINDING	DAY OF DEATH
FEMALES 2000 MG/KG
1		No findings noted	Scheduled necropsy Day 15 after treatment
FEMALES 2000 MG/KG
2 3		No findings noted No findings noted	Scheduled necropsy Day 15 after treatment Scheduled necropsy Day 15 after treatment

 

IRRITATION

SEX/DOSE LEVEL	ANIMAL	24 HOURS		48 HOURS		72 HOURS
		Erythema	Oedema	Erythema	Oedema	Erythema	Oedema
FEMALES 2000 MG/KG
	1	1	0	1	0	1	0
FEMALES 2000 MG/KG
	2 3	2 1	0 0	2 1	0 0	2 1	0 0

 

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal LD50 value of PPDI in Wistar rats was established to exceed 2000 mg/kg body weight.
Based on these results, PPDI does not have to be classified and has no obligatory labelling requirement for acute dermal 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 to determine the potential toxicity of Paraphenylene diisocyanate (PPDI), when given by a single dermal dose.

The study was carried out based on the guidelines described in:

-OECD No. 402 (2017) "Acute Dermal Toxicity"

Initially, PPDI was administered to a single female Wistar rat by a single dermal application at 2000 mg/kg body weight for 24 hours in a range finder study. Based on the results, the main study was performed by dosing two females at 2000 mg/kg. All animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed on the day of death or after terminal sacrifice (Day 15).

 

RESULTS

No mortality occurred.

Very slight to well-defined erythema, fissures, scales, scabs and white discoloration were noted for the treated skin area of the animals between Days 2 and 15.

Hunched posture, shallow respiration, piloerection and/or chromodacryorrhoea of the snout were noted for the animals between Days 1 and 4.

The body weight gain shown by the surviving animals during the observation period was within the range expected for rats used in this type of study.

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

 

CONCLUSION

The dermal LD50 value of PPDI in Wistar rats was established to exceed 2000 mg/kg body weight.

Based on these results, PPDI does not have to be classified and has no obligatory labelling requirement for acute dermal 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).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

Oral toxicity

P-phenylene diisocyanate was administered as a single oral gavage to overnight fasted (16 to 18 hours) three female rats (G1-FTS) at the dose of 2000 mg/kg body weight. There were no clinical signs of toxicity and pre-terminal deaths. Based on the scheme - Annex 2d of the guideline OECD 423, three additional female rats were tested at the same dose of 2000 mg/kg body weight (G1-STS). There were no clinical signs of toxicity and pre-terminal deaths. Based on the scheme - Annex 2d of the guideline OECD 423, the dose was stopped The rats were observed for mortality and clinical signs for 14 days post treatment. Body weights were recorded prior to dosing on day 1 and again on days 8 and 15. Necropsy was performed for all the rats at termination. All survived rats gained weight during experimental period. There were no gross pathological changes at necropsy. Based on the results of the present study, the test item, P-phenylene diisocyanate, The LD50 is 5000 mg/kg body weight or Unclassified as per LD50 cut-off value.

Dermal

Initially, PPDI was administered to a single female Wistar rat by a single dermal application at 2000 mg/ kg body weight for 24 hours in a range finder study. Based on the results, the main study was performed

by dosing two females at 2000 mg/kg. All animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed on the day of death or after terminal sacrifice (Day 15). No mortality occurred. Very slight to well-defined erythema, fissures, scales, scabs and white discoloration were noted for the treated skin area of the animals between Days 2 and 15.

Hunched posture, shallow respiration, piloerection and/or chromodacryorrhoea of the snout were noted for the animals between Days 1 and 4. The body weight gain shown by the surviving animals during the observation period was within the range expected for rats used in this type of study. No abnormalities were found at macroscopic post mortem examination of the animals. The dermal LD50 value of PPDI in Wistar rats was established to exceed 2000 mg/kg body weight.

Inhalation

Due to the large, non-respirable particulate formed at high concentrations, it was apparent that an appropriate estimation of the LC50 could not be established from the data. Under the conditions of

this study, the approximate lethal concentration (ALC) could be determined, and it was considered to be 335 mg/m3 total H-19056.

Justification for classification or non-classification

Based on the acute toxicity data available the substance will be classified for Acute Tox. 2 (inhalation).