Phosphoric acid, isononyl ester

Endpoint summary

Description of key information

The oral LD50 of the substance in the rat was approximately 2500 mg/kg. Acute dermal and acute inhalation studies were not conducted due to the corrisivity of the substance.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

The study was performed between 30 June 2011 and 26 July 2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results. Reliability downgraded from Klimisch 1 to 2 since study being used for read-across.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese MAFF, 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Female Wistar (RccHan:WIST) strain rats were supplied by Harlan Laboratories UK Ltd., Oxon, UK.
- Age at study initiation: Eight to twelve weeks of age
- Weight at study initiation: 158 - 183 g
- Fasting period before study: Overnight fast immediately before dosing and for approximately three to four hours after dosing
- Housing: The animals were housed in groups of three in suspended solid floor polypropylene cages furnished with woodflakes.
- Diet (e.g. ad libitum): Food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK) was allowed throughout the study.
- Water (e.g. ad libitum): Free access to mains drinking water was allowed throughout the study.
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Set to achieve limits of 19 to 25°C
- Humidity (%): Set to achieve limits of 30 to 70%
- Air changes (per hr): At least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 30 mg/ml or 200 mg/ml


MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

DOSAGE PREPARATION: The test item was freshly prepared, as required, as a solution at the appropriate concentration in distilled water.
The test item was formulated within two hours of being applied to the test system. It is assumed that the formulation was stable for this duration.


CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: Using available information on the toxicity of the test item, 300 mg/kg was chosen as the starting dose.

Doses:

300 mg/kg and 2000 mg/kg

No. of animals per sex per dose:

3 females at 300 mg/kg.
6 females at 2000 mg/kg

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 hours after dosing and subsequently once daily for up to fourteen days.
Individual bodyweights were recorded prior to dosing and seven and fourteen days after treatment or at death.

- Necropsy of survivors performed: yes; At the end of the observation period the surviving animals were killed by cervical dislocation. All animals were subjected to gross pathological examination. This consisted of an external examination and opening of the abdominal and thoracic cavities for examination of major organs. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Sex:

female

Dose descriptor:

LD50

Effect level:

2 500 mg/kg bw

Based on:

test mat.

Mortality:

Individual mortality data are given in Table 1.
One animal treated at a dose level of 2000 mg/kg was found dead two days after dosing.

Clinical signs:

other: Individual clinical observations are given in Table 2 and Table 3. Signs of systemic toxicity noted in one animal treated at a dose level of 2000 mg/kg were increased salivation, red/brown staining around the snout and noisy respiration. There were no ot

Gross pathology:

Individual necropsy findings are given in Table 6 and Table 7.
Abnormalities noted at necropsy of the animal that died during the study were patchy pallor of the liver, dark spleen, dark kidneys and haemorrhage of the gastric mucosa. No other abnormalities were noted at necropsy of animals that were killed at the end of the study.

Table 1: Mortality Data

Dose Level mg/kg	Sex	Number of Animals Treated	Deaths During Day of Dosing (Hours)				Deaths During Period After Dosing (Days)								Deaths
			½	1	2	4	1	2	3	4	5	6	7	8-14
300	Female	3	0	0	0	0	0	0	0	0	0	0	0	0	0/3
2000	Female	3	0	0	0	0	0	0	0	0	0	0	0	0	0/3
	Female	3	0	0	0	0	0	1	0	0	0	0	0	0	1/3

Table 2: Individual Clinical Observations - 300 mg/kg

Dose Level mg/kg	Animal Number and Sex	Effects Noted After Dosing (Hours)				Effects Noted During Period After Dosing (Days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
300	1-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-1 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0= No signs of systemic toxicity

Table 3: Individual Clinical Observations - 2000 mg/kg

Dose Level mg/kg	Animal Number and Sex	Effects Noted After Dosing (Hours)				Effects Noted During Period After Dosing (Days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	2-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-1 Female	SSs	SSs	S	Rn	Rn	Rn	Rn	0	0	0	0	0	0	0	0	0	0	0
	2-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-1 Female	0	0	0	0	0	X
	3-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0= No signs of systemic toxicity           

Rn = Noisy respiration

S = Increased salivation

Ss = Red/brown staining around the snout

X = Animal dead

Table 4: Individual Bodyweights and Weekly Bodyweight Changes - 300 mg/kg

Dose Level mg/kg	Animal Number and Sex	Bodyweight (g) at Day			Bodyweight Gain (g) During Week
		0	7	14	1	2
300	1-0 Female	177	203	210	26	7
	1-1 Female	158	173	180	15	7
	1-2 Female	183	210	220	27	10

Table 5: Individual Bodyweights and Weekly Bodyweight Changes - 2000 mg/kg

Dose Level mg/kg	Animal Number and Sex	Bodyweight (g) at Day			Bodyweight (g) at Death	Bodyweight Gain (g) During Week
		0	7	14		1	2
2000	2-0 Female	177	182	193		5	11
	2-1 Female	171	174	189		3	15
	2-2 Female	169	177	191		8	14
	3-0 Female	162	177	183		15	6
	3-1 Female	158	-	-	150	-	-
	3-2 Female	168	174	180		6	6

Table 6: Individual Necropsy Findings - 300 mg/kg

Dose Level mg/kg	Animal Number and Sex	Time of Death	Macroscopic Observations
300	1-0 Female	Killed Day 14	No abnormalities detected
	1-1 Female	Killed Day 14	No abnormalities detected
	1-2 Female	Killed Day 14	No abnormalities detected

Table 7: Individual Necropsy Findings - 2000 mg/kg

Dose Level mg/kg	Animal Number and Sex	Time of Death	Macroscopic Observations
2000	2-0 Female	Killed Day 14	No abnormalities detected
	2-1 Female	Killed Day 14	No abnormalities detected
	2-2 Female	Killed Day 14	No abnormalities detected
	3-0 Female	Killed Day 14	No abnormalities detected
	3-1 Female	Found Dead Day 2	Liver: patchy pallor Spleen: dark Kidneys: dark Gastric mucosa: haemorrhagic
	3-2 Female	Killed Day 14	No abnormalities detected

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was approximately 2500 mg/kg bodyweight (Globally Harmonised Classification System - Category 5, >2000 - 5000 mg/kg bodyweight).

Executive summary:

Introduction.

The study was performed to assess the acute oral toxicity of the test item following a single oral administration in the Wistar strain rat. The method was designed to be compatible with the following:

- OECD Guidelines for the Testing of Chemicals No. 423 “Acute Oral Toxicity – Acute Toxic Class Method” (adopted 17 December 2001)

- Method B1 tris Acute Toxicity (Oral) of CommissionRegulation (EC) No. 440/2008

Method. 

A group of three fasted females was treated with the test item at a dose level of 300 mg/kg bodyweight. Based on the results from this dose level further groups of fasted females were treated at a dose level 2000 mg/kg bodyweight. Dosing was performed sequentially.

The test item was administered orally as a solution in distilled water. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

Mortality. 

One animal treated at a dose level of 2000 mg/kg was found dead two days after dosing. 

Clinical Observations. 

Signs of systemic toxicity noted in one animal treated at a dose level of 2000 mg/kg were increased salivation, red/brown staining around the snout and noisy respiration. There were no other signs of systemic toxicity noted.

Bodyweight. 

The surviving animals showed expected gains in bodyweight over the study period.

Necropsy. 

Abnormalities noted at necropsy of the animal that died during the study were patchy pallor of the liver, dark spleen, dark kidneys and haemorrhage of the gastric mucosa. No other abnormalities were noted at necropsy of animals that were killed at the end of the study.

Conclusion. 

The acute oral median lethal dose (LD₅₀) of the test item in the female Wistar strain rat was approximately 2500 mg/kg bodyweight (Globally Harmonised Classification System ‑ Category 5, >2000 ‑ 5000 mg/kg bodyweight).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 500 mg/kg bw

Quality of whole database:

Sufficient to meet data requirements. The study is Klimisch 2 (due to read-across only).

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Study waived on the basis of the corrosivity of the substance. In addition it is not volatile so inhalation is not a significant route of exposure.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Study waived on the basis of the corrosivity of the substance.

Additional information

The acute toxicity assessment of isononyl phosphate is based on read-across data from the structurally related substance 2-ethylhexyl phosphate (CAS 12645-31-7).

Acute Oral Toxicity

In a reliable study the acute oral median lethal dose (LD₅₀) of the test item in the female Wistar strain rat was approximately 2500 mg/kg bodyweight.

 

Acute Dermal/Inhalation Toxicity

Acute dermal and acute inhalation studies were not conducted as the substance is classified as corrosive. Effects would be dominated by local tissue damage. The low acute oral toxicity indicates a low systemic toxicity.

Justification for selection of acute toxicity – oral endpoint
Only one study available on the substance.

Justification for classification or non-classification

The substance does not meet the criteria for classification for acute toxicity via the oral route based on the result of an acute oral toxicity study conducted on a related substance, giving a LD₅₀of approximately 2500 mg/kg.The substance is corrosive and therefore no acute dermal or inhalation toxicity studies were conducted.