Phosphoric acid, bis(1,1-dimethylethyl) ester

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

2012-07-23 to 2012-12-04

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read-across with Di-tert-butyl potassium phosphate. Study conducted in compliance with international standard guidelines under GLP conditions. The study report was well documented with all mandatory information included.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2012

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: 12 NohSan N° 8147, JMAFF 2002

Deviations:

no

Principles of method if other than guideline:

Not applicable.

GLP compliance:

yes (incl. QA statement)

Remarks:

(2012-09-07)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

33494-80-3

Cas Number:

33494-80-3

IUPAC Name:

33494-80-3

Constituent 2

Reference substance name:

Di-tert-butyl potassium phosphate (DTBPOK)

IUPAC Name:

Di-tert-butyl potassium phosphate (DTBPOK)

Test material form:

solid: crystalline

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Oxon, UK
- Age at study initiation: eight to twelve weeks
- Weight at study initiation: The bodyweights fell within an interval of ±20% of the mean initial bodyweight of the first treated group (from 159g to 173 g)
- Fasting period before study: Yes
- Housing: in groups of three in suspended solid-floor polypropylene cages furnished with woodflakes
- Diet (e.g. ad libitum): 2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK
- Water (e.g. ad libitum): free access to mains drinking
- Acclimation period: at least five days

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

IN-LIFE DATES: From: 20 September 2012 To: 18 October 2012

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
For the 2000 mg/kg dose level:
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg
- Justification for choice of vehicle: No data
- Lot/batch no. (if required): No data
- Purity: No data

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: Based on results of available data

Doses:

2000 mg/kg bw.

No. of animals per sex per dose:

3 per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
+ Observations: The first day: 0.5h, 1h, 2h, 4h and then once daily
+ Weighing: day 0, 7 and 14

- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross necropsy

Statistics:

No statistics were performed.

Results and discussion

Preliminary study:

Not applicable.

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks:

DTBPOK

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 372 mg/kg bw

Based on:

act. ingr.

Remarks:

di-tert-butyl phosphate

Mortality:

There were no deaths.

Clinical signs:

other: No signs of systemic toxicity were noted.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

No data.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the test conditions of this study, the acute oral median lethal dose (LD50) of Di-tert-butyl potassium phosphate in rat was estimated to be greater than 2000 mg/kg bw. The acute oral median lethal dose (LD50) of Di-tert-butyl phosphate in rat was calculated to be greater than 2372 mg/kg bw.

Executive summary:

The acute oral toxicity study was assessed on the potassium salt analogue of the target substance, di-tert-butyl potassium phosphate, in a study according to acute toxicity class method procedure (OECD Guideline 423; EC test method B1.tris, EPA OPPTS 870.1100 and Japanese MAFF, 2000) and in accordance with GLP.

No abnormalities were detected in the two groups tested at 2000 mg/kg bw.

Under the test conditions of this study, the acute oral median lethal dose (LD50) of Di-tert-butyl potassium phosphate in rat was estimated to be greater than 2000 mg/kg bw. The acute oral median lethal dose (LD50) of Di-tert-butyl phosphate in rat was calculated to be greater than 2372 mg/kg bw. Based on these data, no classification is required for both Di-tert-butyl potassium phosphate and Di-tert-butyl phosphate according to EU criteria.