Phosphoric acid, bis(1,1-dimethylethyl) ester, potassium salt (1:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

between 2012-07-23 to 2012-10-31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

In accordance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

2012-09-07

Test material

Test material information

Constituent 1

Reference substance name:

Potassium di-tert-butyl phosphate

EC Number:

619-702-9

Cas Number:

33494-80-3

Molecular formula:

C8H18KO4P

IUPAC Name:

Potassium di-tert-butyl phosphate

Test material form:

solid: crystalline

In vitro test system

Test system:

human skin model

Source species:

human

Details on test system:

SOURCE AND COMPOSITION OF MEMBRANE BARRIER USED
- Was the Corrositex® test kit used: Yes
Lot number CT052112
Expiry date May 2014

WAS THE COMPATIBILITY TEST PERFORMED: Yes

WAS THE TIMESCALE CATEGORY TEST PERFORMED: Yes

METHOD OF DETECTION
- Chemical or electrochemical detection system: Chemical detection system

METHOD OF APPLICATION: A membrane disc was placed on top of the vials. An aliquot of test item occupying 0.5 ml was evenly applied onto the top of the membrane disc.

NUMBER OF REPLICATES: 4

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the mean breakthrough time is less than 60 min as the substances was categorized in Category 2.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml

VEHICLE
No vehicle

NEGATIVE CONTROL
- Concentration (if solution): 10% w/v

Duration of treatment / exposure:

60 min

Number of replicates:

4

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

1 to 4

Value:

> 60

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Qualification Screen

The test item produced an immediate colour change therefore qualified for use in the CORROSITEX assay.

Categorisation Screen

The test item was assigned into Category 2.

Assay

	Test item Breakthrough Time
	Vial 1	Vial 2	Vial 3	Vial 4
Start time (hr:min:sec)	00:00:00	00:04:00	00:05:00	00:06:00
Detection time (hr:min:sec)	Not applicable	Not applicable	Not applicable	Not applicable
Breakthrough time (hr:min:sec)	Not applicable	Not applicable	Not applicable	Not applicable

 

No breakthrough observed after 60 minutes

  

 

The results of the assay were accepted on condition of adherence to the positive and negative control item ranges given in the following table:

	Chemical	Concentration (weight %)	Breakthrough Time (hr:min:sec)
Positive Control	Sulphuric Acid	95 – 98	00 :01 :00
Negative Control	Citric Acid	10	>60 minutes

hr = hour(s)

min = minute(s)

sec = second(s)

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was considered to be non-corrosive.

Executive summary:

This in vitro study was performed to assess the skin corrosion potential of DTBPOK, in a corrositex assay according to the OECD 435 Guideline and GLP.

The qualification screen qualified the test item for the corrositex assay. The test item was assigned to category 2.

The results for the positive and negative control were acceptable.

In all four replicates, the breakthough time was > 60 minuges. Therefore, DTBPOK is considered to be non-corrosive.