Registration Dossier

Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
16 Aug 2011 to 12 Sep 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report date:
2011

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
Deviations:
yes
Remarks:
The study integrity was not adversely affected by the deviations.
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
N-tert-butylglycyl chloride hydrochloride (1:1)
EC Number:
618-771-2
Cas Number:
915725-52-9
Molecular formula:
C6H13Cl2NO
IUPAC Name:
N-tert-butylglycyl chloride hydrochloride (1:1)
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Purity Not indicated by the sponsor; treated as 100% pure Test substance storage In refrigerator (2-8°C) in the dark Stability under storage conditions Stable Expiry date 21 July 2012

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Cell source:
other: MatTek Corporation, Ashland MA, U.S.A
Source strain:
not specified
Justification for test system used:
Recommended test system in international guidelines (OECD and EC).
Details on test system:
EpiDerm Skin Model (EPI-200, Lot no.: 15600 kit U). The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm²) were cultured on polycarbonate membranes of 10 mm cell culture inserts.
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
Skin tissue was moistened with 25 µl of Milli-Q water and 25 mg of N-t-butylglycine acid chloride HCl
Duration of treatment / exposure:
3 minutes and 1 hour
Number of replicates:
3

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3-minute application viability (percentage of control) -negative control
Value:
ca. 100
Vehicle controls validity:
not specified
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3-minute application viability (percentage of control) -N-t-butylglycine acid chloride HCl
Value:
ca. 86
Vehicle controls validity:
not specified
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
positive indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3-minute application viability (percentage of control) -Positive Conrol
Value:
ca. 17
Vehicle controls validity:
not specified
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
positive indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
1-hour application viability (percentage of control) - Negative Control
Value:
ca. 100
Vehicle controls validity:
not specified
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
1-hour application viability (percentage of control) - N-t-butylglycine acid chloride HCl
Value:
ca. 12
Vehicle controls validity:
not specified
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
positive indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
1-hour application viability (percentage of control) -positive control
Value:
ca. 12
Vehicle controls validity:
not specified
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
positive indication of irritation
Other effects / acceptance of results:
The in vitro skin corrosion test is considered acceptable if it meets the following criteria: a) The absolute mean OD540 of the two tissues of the negative control should reasonably be within the laboratory historical control data range. b) The mean relative tissue viability following 3-minute exposure to the positive control should be <= 30%. c) The maximum inter-tissue variability (in viability) is 30% between two tissues treated identically. d) The maximum difference in percentage between the mean viability of two tissues and one of the two tissues is 15%

Applicant's summary and conclusion

Interpretation of results:
Category 1 (corrosive) based on GHS criteria
Conclusions:
Finally, it is concluded that this test is valid and that N-t-butylglycine acid chloride HCl is corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.
Executive summary:

In vitro skin corrosion test with N-t-butylglycine acid chloride HCl using a human skin model.

This report describes the ability of N-t-butylglycine acid chloride HCl to induce skin corrosion on a human three dimensional epidermal model (EpiDerm (EPI-200)). The possible corrosive potential of  N-t-butylglycine acid chloride HCl was tested through topical application for 3 minutes and 1 hour.

The study procedures described in this report were based on the most recent OECD and EC guidelines.

Batch # 11560006 of N-t-butylglycine acid chloride HCl was a beige powder. Skin tissue was moistened with 25 µl of Milli-Q water and 25 mg of N-t-butylglycine acid chloride HCl was applied directly on top of the skin tissue

The positive control had a mean relative tissue viability of 17% after 3 minutes exposure. The absolute mean OD540 (optical density at 540 nm) of the negative control tissues was within the laboratory historical control data range for the 3-minute exposure time. For the 1-hour exposure time the absolute mean OD540 of the negative control tissues was just below the laboratory historical control data range. The maximum inter-tissue variability in viability between two tissues treated identically was less than 21% and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues was less than 12%, indicating that the test system functioned properly.

Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with N-t-butylglycine acid chloride HCl compared to the negative control tissues was 86% and 12%, respectively. Because the mean relative tissue viability for N-t-butylglycine acid chloride HCl was below 15% after the 1-hour treatment it is considered to be corrosive.

Finally, it is concluded that this test is valid and that N-t-butylglycine acid chloride HCl is corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.