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Description of key information

1-methyl piperazine was test for skin and eye irritation in some old but scientifically valid studies.  Corrosive effects were seen in both the eyes and in the skin after 5 minutes or longer exposure.  1-methyl  piperazine has not been tested for respiratory irritation, its effects on the skin and in the eyes would suggest that it is likely to be irritant to the respiratory tract if inhaled, but we have no specific information to confirm this. A corrositex study was doen to confirm the transport packing group, this can also be translated into GHS classification for users

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
14. Nov 1967 - 23. Nov 1967
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented report which meets basic scientific principles.
Principles of method if other than guideline:
Method: BASF-Test.
Two animals were treated for 1, 5, 15 min using occlusive conditions. An application site of 2.5x2.5 cm was covered with the liquid test substance. After the application time (1, 5, 15 min) the skin was washed with Lutrol (conc.) and Lutrol/water (1:1). The animals were observed for 8 days and skin changes were recorded daily. The report describes findings after 24 hours and at the end of the observation period (8 days). For a final evaluation, the findings after 48 and 72 hours from the raw data were taken into account.
GLP compliance:
not specified
Species:
rabbit
Strain:
Vienna White
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 3.43 and 3.93 kg
Type of coverage:
occlusive
Preparation of test site:
not specified
Vehicle:
unchanged (no vehicle)
Controls:
not specified
Duration of treatment / exposure:
1, 5 and 15 min and 20 h.
Observation period:
8 days
Number of animals:
2
Details on study design:
TEST SITE
- Area of exposure: 2.5x2.5 cm

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with Lutrol (conc.) and Lutrol/water (1:1).
- Time after start of exposure: 1, 5 and 15 min post application

Irritation parameter:
erythema score
Remarks:
1 min exposure
Basis:
mean
Time point:
24/48/72 h
Score:
3
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
edema score
Remarks:
I min exposure
Basis:
mean
Time point:
24/48/72 h
Score:
3
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
erythema score
Basis:
mean
Time point:
24/48/72 h
Score:
> 4
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Remarks on result:
probability of severe irritation
Remarks:
Necrosis
Irritation parameter:
edema score
Basis:
mean
Time point:
24/48/72 h
Score:
> 4
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Remarks on result:
probability of severe irritation
Remarks:
Necrosis
Irritant / corrosive response data:
1 min exposure: heavy redness
5 min exposure: heavy redness and moderate necrosis.
15 min exposure: heavy redness and necrosis.
20 h exposure: heavy necrosis and necrosis.

Mean erythema/necrosis score after 24, 48 and 72 h (animal1/2)

 Exposure time  24 h  48 h  72 h  
 1 min 3/3 3/3 3/3  
 5 min 3/N+ N+/N+ N+/N+  
 15 min N+/N++ N+/N++ N+/N++
 20 h N++/N++ N++/N++ N++/N++

The original BASF grading was converted into the numerical grading according the OECD Draize system.

N+: parchment-like necrosis.

N++: hart, leathery necrosis.

The application of the test substance caused necrosis to the exposed skin.

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
other information
Study period:
The study was performed between 30 November 2011 and 01 December 2011.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.
Qualifier:
according to
Guideline:
OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)
Deviations:
no
Qualifier:
according to
GLP compliance:
yes (incl. certificate)
Species:
other: Chemical Detection System
Strain:
other: Chemical Detection System
Details on test animals and environmental conditions:
Not applicable
Type of coverage:
other: Direct Contact
Preparation of test site:
other: Solubilisation of Biobarrier Matrix
Vehicle:
other: No vehicle used
Controls:
other: Colur Control Vial
Amount / concentration applied:
TEST MATERIAL

- The test Material was applied neat.

- Amount(s) applied (volume or weight with unit):
Approximately 500 µl of the test material was applied to the memebrane disc.

- Concentration (if solution):
The test material was used as supplied.

VEHICLE
No vehicle used
Duration of treatment / exposure:
4 hours or until breakthrough of the test item had occurred.
Observation period:
4 hours or until breakthrough of the test item had occurred.
Number of animals:
Not applicable
Details on study design:
TEST SITE
- Area of exposure:
Approximately 500 µl of the test material was applied to the memebrane disc.

- % coverage:
The test material was applied topically to ensuring uniform covering.

- Type of wrap if used:
Not Applicable.

REMOVAL OF TEST SUBSTANCE
- Washing (if done):
Removal unnecessary in this test system.

- Time after start of exposure:
Not Applicable.

SCORING SYSTEM:
Breakthrough. The indication of breakthrough of the test item was detected as a change, either in colour or in physical appearance, in the CDS compared to the negative control.
The United Nations Packing Group Classification (I/II/III/Non-Corrosive) was determined on the basis of the average time that was required for the test item to produce a change in the CDS (breakthrough time). The following classification tables (provided by In Vitro International with the approval of the US DOT (exemption DOT-E 10904)) were used:
Table 1 Category 1 Test Items
Corrosivity Packing Group Mean Breakthrough Time (minutes)
Corrosive I 0 – 3
Corrosive II >3 – 60
Corrosive III >60 – 240
Non-Corrosive Not applicable >240
Table 2 Category 2 Test Items
Corrosivity Packing Group Mean Breakthrough Time (minutes)
Corrosive I 0 – 3
Corrosive II >3 – 30
Corrosive III >30 – 60
Non-Corrosive Not applicable >60
Irritation / corrosion parameter:
other:
Remarks on result:
other:
Remarks:
Basis: other: Time required for Test Item to Produce a Colour Change. Time point: 240 Minutes. Reversibility: other: Not applicable. Remarks: See mean breakthrough time below.. (migrated information)
Irritant / corrosive response data:
Mean Breakthrough time of the four test item replicates: 48 minutes 41 seconds
Other effects:
No

RESULTS

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 1.

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)

00:50:30

00:52:00

00:52:10

00:55:04

Breakthrough Time (hr:min:sec)

00:50:30

00:48:00

00:47:10

00:49:04

Mean Breakthrough time of the four test item replicates:48 minutes 41 seconds

CORROSITEX CLASSIFICATION:                       CORROSIVE PACKING GROUP II 

 Positive/Negative Controls Quality Criteria

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

Positive Control

Sulphuric Acid

95 – 98%

52 seconds

Negative Control

Citric Acid

10%

>60 minutes


hr=    hour(s)

min =  minute(s)

sec =  second(s)

Interpretation of results:
Category 1B (corrosive) based on GHS criteria
Remarks:
Migrated information
Conclusions:
The test item was considered to be CORROSIVE and can be assigned the UN Packing Group Criteria II.
Executive summary:

Introduction.

The test item was assessed for its corrosivity potential using the CORROSITEX assay. The method was designed to be compatible with the following:

OECD Guidelines for the Testing of Chemicals No. 435 “In VitroMembrane Barrier Test Method for Skin Corrosion” (adopted 19 July 2006)

Method.

The assay consisted of:

a qualification screen with the Chemical Detection System

a categorisation screen to identify test items as having either a high or low acid/alkaline reserve

a definitive CORROSITEX assay

Results. 

Sample qualified                  :          YES

Sample category                  :          1

Mean Breakthrough time     :          48 minutes 41 seconds

Conclusion.

The test item was considered to be CORROSIVE and can be assigned the UN Packing Group Criteria II.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (corrosive)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08. Nov 1967 - 16. Nov 1967
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented report which meets basic scientific principles.
Principles of method if other than guideline:
Method: BASF-Test. 50 µL of the test substance were applied to the conjunctival sac of one eye in 2 animals. The animals were observed after 10 min, 1 and 24 h on the day of treatment and on day 3 and 8 afterwards. The eyes were not washed out after 24 hours as specified in OECD Guideline 405.
GLP compliance:
not specified
Species:
rabbit
Strain:
Vienna White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 2.63 and 2.68 kg
Vehicle:
unchanged (no vehicle)
Controls:
other: The adjacent eye served as saline control.
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µl
Duration of treatment / exposure:
single application
Observation period (in vivo):
8 days
Number of animals or in vitro replicates:
2
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
24 h
Score:
3
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
24 h
Score:
2
Max. score:
3
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
24 h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
24 h
Score:
3
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
fully reversible
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
24 h
Score:
0
Max. score:
4
Reversibility:
fully reversible
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
48 h
Score:
3
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
48 h
Score:
2
Max. score:
4
Reversibility:
fully reversible
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
48 h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: within 8 days
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
48 h
Score:
3
Max. score:
4
Reversibility:
not fully reversible within: 8 days
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
48 h
Score:
0
Max. score:
4
Reversibility:
fully reversible
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
48 h
Score:
0
Max. score:
4
Reversibility:
fully reversible
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
72 h
Remarks on result:
not measured/tested
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
72 h
Remarks on result:
not measured/tested
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
72 h
Remarks on result:
not measured/tested
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
72 h
Remarks on result:
not measured/tested
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
72 h
Remarks on result:
not measured/tested
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
72 h
Remarks on result:
not measured/tested
Irritation parameter:
iris score
Basis:
animal #1
Time point:
24/48/72 h
Remarks on result:
not measured/tested
Irritation parameter:
iris score
Basis:
animal #2
Time point:
24/48/72 h
Remarks on result:
not measured/tested

Findings: animal1/animal2

 Time corneal opacity  erythema chemosis      
 1 h 3/3 0/0 0/0       
 24 h 3/3 2/0  2/0      
 48 h 3/3 2/0 2/0         
 72 h -/- -/-  -/-      
 8 d 3/3 2/0 0/2        

The original BASF grading was converted into the numerical grading according the OECD Draize system.

The 72 h reading is missing.

Mean values over 24 and 48 h (the 72 h reading is missing).

Animal1: Erythema: 2 ; Opacity: 3; Chemosis: 2;

Animal2: Erythema: 0 ; Opacity: 3; Chemosis: 0;

At the end of the observation period after 8 days the eyes were covered with purulence and crust formation was found in the periphery. In one animal after 5 days staphyloma formation was induced. The latter and opacity grade 3 are considered to be irreversible findings.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

1-methyl piperazine showed clear corrosive effects on the skin in rabbits after exposures from 5 minute and above, but only severe irritation after 1 minute exposure. In order to be able to classify 1-methyl piperazine for skin corrosion, exposure for up to 3 minutes and observation after 1 hour are required to indicate if classification as category 1A or 1B is required. In the absence of this information an in vitro Corrositex study was commissioned, this study showed an average membrane breakthrough time of 48 minutes and 41 seconds.

1-methyl piperazine produced irreversible damage to the cornea of rabbits scoring 3 in all rabbits at the end of the 8 day observation period. In the absence of any specific data on irritation to the respiratory tract from inhalation of 1-methyl piperazine it is not proposed to classify for respiratory irritation.

We have no test data for respiratory irritation. Inhalation is not an expected route of exposure but based on its eye and skin corrosion 1-methyl piperazine would be expected to cause irritation to the respiratory tract if inhaled. However in the absence of any specific information it is not considered that a classification is required under EU CLP (GHS) for respiratory irritation.

Justification for selection of skin irritation / corrosion endpoint:

There are two skin irritation studies available one is an in vivo study in rabbits BASFAGXVII/37.3.skin irritation/corrosion, this study is Klimisch 2 as it was pre-GLP and guidelines but is scientifically valid, with the test substance identified as monomethyl piperazine of 99% purity.  Exposure for 5 minutes, 15 minutes and 20 hours all resulted in necrosis at the 24/48 and 72 hour observationsb as there was no 3 minute exposure time of observations recoded before 24 hours, this study while showing clear evidence of skin corrosion cannot distinguish between GHS category 1A or 1B.

There is therefore a second study to clarify the classification it was not considered ethical to perform an animal study instead an in vitro study was done, Acute Toxicity in vitro. Skin corrosion-CORROSITEX N-methyl piperazine.41104632.  This study uses time of penetration of a synthetic membrane to distinguish between UN Packaging groups I, II and III corrosives, which correspond to GHS category 1A, 1B and 1C.  In this study 1-methyl piperazine showed average membrane breakthrough times of 48 minutes and 41 seconds.  The study is Klimisch 1 carried out to GLP and according to the agreed protocol.

Justification for selection of eye irritation endpoint:

There is an eye irritation study in rabbits available.  This study is Klimisch 2 as it is an old study pre-GLP and pre guidelines, the study is however scientifically valid with sufficient details to be acceptable.  In this study severe effects were seen in the eyes of the rabbits with corneal opacity graded at 3 in all rabbits at the end of the eight day observation period.  The severe effects were considered to be irreversible damage.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

1-methyl piperazine showed clear corrosive effects on the skin in rabbits after exposures from 5 minute and above, but only severe irritation after 1 minute exposure. In order to be able to classify 1-methyl piperazine for skin corrosion, exposure for up to 3 minutes and observation after 1 hour are required to indicate if classification as category 1A or 1B is required. In the absence of this information an in vitro Corrositex study was commissioned, this study showed an average membrane breakthrough time of 48 minutes and 41 seconds, using the criteria for this test >3 -60 minutes corresponds to the UN packing group II for skin corrosion. The UN pack packing groups I, II and III under GHS correspond to category 1A, 1B and 1C for skin corrosion. Therefore 1-methyl piperazine is classified as Category 1B for skin corrosion by the EU CLP (GHS) criteria based on a combination of the in vivo and in vitro studies.

1-methyl piperazine produced irreversible damage to the cornea of rabbits and therefore it is classified as Category 1 for eye damage/irritation by the EU CLP (GHS) criteria.

In the absence of any specific data on irritation to the respiratory tract from inhalation of 1-methyl piperazine it is not proposed to classify for respiratory irritation.