Phosphoric acid, mono- and di-C11-14 (linear and branched) alkyl esters

Endpoint summary

Description of key information

Acute oral toxicity: LD50 rat, males and females > 2000 mg/kg bw, OECD Guideline 420, GLP   Acute dermal toxicity No acute dermal toxicity studies are available for Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters. Relevant, reliable and adequate data are available for the closely related substances Aluminium dicetyl phosphate (= Aluminium dihexadecyl phosphate) and Dihexadecyl phosphate. Dermal LD50 rat and rabbit, males and females > 2000 mg/kg bw      Acute inhalative toxicity According to REACH regulation, Annex VII, 8.5.2, an acute inhalation toxicity study is not required. Inhalation is no relevant route of exposure and testing by inhalation is not appropriate. Exposure of humans via inhalation is unlikely taking into account the possibility of exposure to aerosols, particles or droplets of an inhalable size.    

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

Study period:

Between 21 August 2012 and 12 September 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Version / remarks:

adopted 17 December 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Female Wistar (RccHan™:WIST) strain rats were supplied by Harlan Laboratories UK Ltd., Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non-pregnant. After an acclimatisation period of at least five days the animals were selected at random and given a number unique within the study by indelible ink marking on the tail and a number written on a cage card. At the start of the study the animals were eight to twelve weeks of age. The bodyweight variation did not exceed ±20% of the bodyweight of the initially dosed animal.
The animals were housed in groups of up to four in suspended solid floor polypropylene cages furnished with woodflakes. With the exception of an overnight fast immediately before dosing and for approximately three to four hours after dosing, free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.
The temperature and relative humidity were set to achieve limits of 19 to 25°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.
The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg bw

Experimental Preparation
For the purpose of the study the test item was freshly prepared, as required, as solution in arachis oil BP. Arachis oil BP was used because the test item did not dissolve/suspend 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. 
No analysis was conducted to determine the homogeneity, concentration or stability of the test item formulation. This is an exception with regard to GLP and has been reflected in the GLP compliance statement.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 female at 2000 mg/kg bw

Control animals:

no

Details on study design:

All animals were dosed once only by gavage using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to its fasted bodyweight at the time of dosing.
Clinical observations were made ½, 1, 2, and 4 hours after dosing and subsequently once daily for fourteen days. Morbidity and mortality checks were made twice daily.
Individual bodyweights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
At the end of the observation period the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Individual mortality data are given in Table 1
There were no deaths.

Clinical signs:

other: Individual clinical observations are given in Table 1 No signs of systemic toxicity were noted.

Gross pathology:

Individual necropsy findings are given in Table 3.
No abnormalities were noted at necropsy.

Evaluation of Data

The test item will be classified according to Annex 3 of the OECD Guidelines for Testing of Chemicals No. 420 "Acute Oral Toxicity - Fixed Dose Method" (adopted 17 December 2001).

Evaluation of data included identification of the number of animals that died during the study (or that were killed for humane reasons), and determination of the nature, severity, onset and duration of the toxic effects. If possible, the signs of evident toxicity were described. Evident toxicity refers to the toxic effects of sufficient severity that administration of the next higher dose level could result in development of severe signs of toxicity and probable mortality. Effects on bodyweights and abnormalities noted at necropsy were also identified.

Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD₅₀) of the test item was made.

The results were also evaluated according to Regulation (EC) No 1272/2008, relating to the Classification, Labelling and Packaging of Dangerous Substances.

Table 1              Individual Clinical Observations and Mortality Data

Dose Level mg/kg bw	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	1-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-1 Female	0	0	0	0	0	0	0	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
	2-3 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 2              Individual Bodyweights and Bodyweight Changes

Dose Level mg/kg bw	Animal Number and Sex	Bodyweight (g) at Day			Bodyweight Gain (g) During Week
		0	7	14	1	2
2000	1-0 Female	152	183	202	31	19
	2-0 Female	156	186	201	30	15
	2-1 Female	165	193	210	28	17
	2-2 Female	152	175	196	23	21
	2-3 Female	156	181	187	25	6

Table 3              Individual Necropsy Findings

Dose Level mg/kg bw	Animal Number and Sex	Time of Death	Macroscopic Observations
2000	1-0 Female	Killed Day 14	No abnormalities detected
	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
	2-3 Female	Killed Day 14	No abnormalities detected

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: other: CLP, EU GHS (Regulation (EC) No 1272/2008)

Conclusions:

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was estimated to be greater than 2000 mg/kg bodyweight (Globally Harmonised Classification System - Unclassified).
The test item does not meet the criteria for classification according to Regulation (EC) No 1272/2008, relating to the Classification, Labelling and Packaging of Dangerous Substances.

Executive summary:

In an acute oral toxicity study according to OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method), adopted 17 December 2001 and EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure), 5 female fasted, 8 to 12 weeks old Wistar (RccHan™:WIST) ratswere given a single oral dose of Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters (100% a.i.) in arachis oil at a limit dose of 2000  mg/kg bw and observed for 14 days.

There were no deaths. No signs of systemic toxicity were noted. All animals showed expected gains in bodyweight over the observation period. No abnormalities were noted at necropsy.

 

Oral LD₅₀females > 2000 mg/kg bw

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The key study is GLP compliant and of high quality (Klimisch score = 1) and no adverse effects also for other routes at highest dose/conc. tested

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Three relevant, reliable (Klimisch score = 2; reliable with restrictions due to read-across) and adequate read-across studies with similar results are available and and no adverse effects also for other routes at highest dose/conc. tested

Additional information

Acute oral toxicity

In an acute oral toxicity study according to OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method), adopted 17 December 2001 and EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure), 5 female fasted, 8 to 12 weeks old Wistar (RccHan™:WIST) rats were given a single oral dose of Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters (100% a.i.) in arachis oil at a limit dose of 2000 mg/kg bw and observed for 14 days.

There were no deaths. No signs of systemic toxicity were noted. All animals showed expected gains in bodyweight over the observation period. No abnormalities were noted at necropsy.

Oral LD50 females > 2000 mg/kg bw

Acute dermal toxicity

No acute dermal toxicity studies are available for Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters. Relevant, reliable and adequate data are available for the closely related substances Aluminium dicetyl phosphate (= Aluminium dihexadecyl phosphate) and Dihexadecyl phosphate. A read across approach is considered appropriate as the registered UVCB substance contains mono- (75%) and dialkylesters (25%) of Phosphoric acid with predominantly C13 and to a smaller extent C12 branched aliphatic alcohols.

The acute dermal toxicity of Aluminium dicetyl phosphate was tested in rats. Additionally, two studies assessing the acute dermal toxicity of Dihexadecyl phosphate are available: one in rats and one in rabbits.

In an acute dermal toxicity study performed comparable to a limit test (OECD guideline 402), 10 female and 10 male young adult rats were dermally exposed to Dihexadecyl phosphate for 24 hours to 10 % of body surface area at a dose of 2000 mg/kg bw. Animals then were observed for 14 days.

Dermal LD50 rat, males and females > 2000 mg/kg bw

No mortality occurred in this limit test. No clinical signs of toxicity were observed throughout the observation period. The skin at the application site showed no changes. No test substance related gross pathological changes were found in any animals.

In an acute dermal toxicity study performed comparable to a limit test (OECD guideline 402), 10 female and 10 male young adult rabbits were dermally exposed to Dihexadecyl phosphate for 24 hours to 10 % of body surface area at a dose of 2000 mg/kg bw. Animals then were observed for 14 days.

Dermal LD50 rabbit, males and females > 2000 mg/kg bw

No mortality occurred in this limit test. No substance related clinical signs of toxicity were observed throughout the observation period. The skin at the application site showed no changes. No test substance related gross pathological changes were found in any animals.

In an acute dermal toxicity study according to OECD guideline 402 performed as limit test, groups of young adult Crl:CDR(SD) BR rats (5 male, 5 female) were dermally exposed to Aluminium dicetyl phosphate moistened with distilled water for 24 hours to 10% of body surface area at a dose of 2000 mg/kg bw. Animals then were observed for 14 days.

Dermal LD50 rat, males and females > 2000 mg/kg bw

No mortality occurred in this limit test. No clinical signs of toxicity were observed throughout the observation period. The skin at the application site showed no changes. No test substance related gross pathological changes were found in any animals.

Acute inhalative toxicity

According to REACH regulation, Annex VII, 8.5.2, an acute inhalation toxicity study is not required. Inhalation is no relevant route of exposure and testing by inhalation is not appropriate. Exposure of humans via inhalation is unlikely taking into account the possibility of exposure to aerosols, particles or droplets of an inhalable size.

Based on the available information, the acute toxicity of Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters is low for oral and dermal routes of administration. There are no data gaps in acute toxicity. Even though there is no information on acute inhalative toxicity, there is no reason to believe that the acute toxicity is higher for this route of exposure. Even though there is no information on acute toxicity in humans, there is no reason to believe that the low acute toxicity observed in experimental animals would not be relevant for human health.

Justification for selection of acute toxicity – oral endpoint
OECD & EC guideline study, no deviations, GLP

Justification for selection of acute toxicity – inhalation endpoint
Inhalation is no relevant route of exposure and testing by inhalation is not appropriate. Exposure of humans via inhalation is unlikely taking into account the possibility of exposure to aerosols, particles or droplets of an inhalable size.

Justification for selection of acute toxicity – dermal endpoint
No single key study has been selected since in all three weight-of-evidence studies no adverse effects were observed up to the limit dose.

Justification for classification or non-classification

Acute oral toxicity

Based on relevant, reliable and adequate data Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters has not to be classified and labelled according to the CLP Regulation (EC) No 1272/2008 and Directive 67/548/EEC with respect to acute oral toxicity.

 

Acute dermal toxicity

Based on relevant, reliable and adequate data of read-across studies with chemically related substances Phosphoric acid, mono- and di- C11-14 (linear and branched) alkyl esters has not to be classified and labelled according to the CLP Regulation (EC) No 1272/2008 and Directive 67/548/EEC with respect to acute dermal toxicity.