4-methylpiperazin-1-amine

Endpoint summary

Description of key information

Skin Irritation:

The dermal irritation potential of4-methylpiperazin-1-aminewas estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

4-methylpiperazin-1-amine was estimated to be irritating to the skin of New Zealand White rabbits.

Based on the estimated results,4-methylpiperazin-1-amine can be considered to be irritating to skin and can be classified under the category “Category 2” as per CLP regulation.

Eye Irritation:

The oculr irritation potential of4-methylpiperazin-1-aminewas estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

4-methylpiperazin-1-amine was estimated to be irritating to the eyes of New Zealand White rabbits.

Based on the estimated results,4-methylpiperazin-1-amine can be considered to be irritating to eyes and can be classified under the category “Category 2” as per CLP regulation.

 

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

data is from OECD QSAR toolbox v3.3 and the QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using OECD QSAR toolbox v3.3

GLP compliance:

not specified

Specific details on test material used for the study:

Name of the test chemical: 4-Methylpiperazin-1-amine
Molecular Formula: C5H13N3
Molecular Weight: 115.179 g/mol
InChI: 1S/C5H13N3/c1-7-2-4-8(6)5-3-7/h2-6H2,1H3
Substance Type: Organic
Physical State: Liquid

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

no data available

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5ml

Duration of treatment / exposure:

4 hours

Observation period:

3 days

Number of animals:

2

Details on study design:

no data available

Other effects / acceptance of results:

no data available

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

72 h

Reversibility:

not specified

Remarks on result:

positive indication of irritation

Irritant / corrosive response data:

Irritation was observed

Estimation method: Takes mode value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

(((((((((((((("a" or "b" or "c" )  and "d" )  and ("e" and ( not "f") )  )  and ("g" and ( not "h") )  )  and "i" )  and "j" )  and ("k" and ( not "l") )  )  and "m" )  and ("n" and ( not "o") )  )  and "p" )  and "q" )  and "r" )  and "s" )  and ("t" and "u" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Aliphatic Amines by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Hydrazine Derivatives by DNA binding by OASIS v.1.3 ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SN1 OR SN1 >> Iminium Ion Formation OR SN1 >> Iminium Ion Formation >> Aliphatic tertiary amines by DNA binding by OECD ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Iminium Ion Formation AND SN1 >> Iminium Ion Formation >> Aliphatic tertiary amines by DNA binding by OECD ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Not possible to classify according to these rules by DPRA Lysine peptide depletion

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Low reactive OR Low reactive >> N-substituted aromatic amides OR Low reactive >> Organic disulfides by DPRA Lysine peptide depletion

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Not possible to classify according to these rules by DPRA Cysteine peptide depletion

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Moderate reactive OR Moderate reactive >> Five-membered heterocyclic urea by DPRA Cysteine peptide depletion

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as weeks - months by Biodeg ultimate (Biowin 3) ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 7) ONLY

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Aliphatic Amines by US-EPA New Chemical Categories

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Alkoxysilanes OR Esters (Acute toxicity) OR Neutral Organics OR Nonionic Surfactants OR Not categorized by US-EPA New Chemical Categories

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Discrete chemical by Substance Type ONLY

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Aliphatic Carbon [CH] AND Aliphatic Carbon [-CH2-] AND Aliphatic Carbon [-CH3] AND Amino, aliphatic attach [-N<] AND Hydrazine [>N-N<] by Organic functional groups (US EPA)

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as >NC(S)C-{O,N,CO}  OR 1,2-Oxaza compounds [N-C-O-] OR 2-Aminoalkyl acetamide [NCOCN<] OR 2-Carbonylamino acetate derivative [OC(=O)CNC(=O)] OR Acetylenic Carbon [#C] OR Acid, aliphatic attach [-COOH] OR Alcohol, olefinic attach [-OH] OR Aliphatic Carbon [C] OR Aliphatic Suflur, one aromatic attach [-S-] OR Alpha-diether [C-O-C-O-C] OR Amide, aliphatic attach [-C(=O)N] OR Amino acid, non-alpha carbon type  OR Amino diol derivative [OCC(N)CO] OR Amino, aliphatic attach [-NH-] OR Amino, aliphatic attach [-NH2] OR Amino-carbonyl compound [NCC(=O)-C] OR Amino-ethylcyano [-N-CH-C#N]  OR Aromatic Carbon [C] OR Benzene to CCN  OR Carbonyl, aliphatic attach [-C(=O)-] OR Carbonyl, olefinic attach [-C(=O)-] OR Carbonyl, one aromatic attach [-C(=O)-] OR Chlorine, aromatic attach [-Cl] OR Chlorine, olefinic attach [-Cl] OR Cyano, aliphatic attach [-C#N] OR Hydroxy, aliphatic attach [-OH] OR Hydroxy, phosphorus attach [-OH] OR Miscellaneous sulfide (=S) or oxide (=O) OR Multi alcohol  OR N-oxoalkyl-2-aminocarboxylic acid [CC(=O)NCCOOH] OR N-oxoalkyl-2-thioalkyl-2-aminocarboxylic acid OR Olefinic carbon [=CH- or =C<] OR Oxygen, aliphatic attach [-O-] OR Phosphine oxide [O=P] OR Suflur {v+4} or {v+6} OR Sulfur, aliphatic attach [-S-] OR Sulphonate, aliphatic attach [-SO2-O] OR Tertiary Carbon OR Tetrahydrazo-1,3-diazine deriv.  [SCC(-N-)COH] by Organic functional groups (US EPA)

Domain logical expression index: "p"

Similarity boundary:Target: CN1CCN(N)CC1
Threshold=10%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "q"

Similarity boundary:Target: CN1CCN(N)CC1
Threshold=20%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "r"

Referential boundary: The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "s"

Similarity boundary:Target: CN1CCN(N)CC1
Threshold=80%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "t"

Parametric boundary:The target chemical should have a value of log Kow which is >= -2.15

Domain logical expression index: "u"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.02

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

4-methylpiperazin-1-amine was estimated to be irritating to the skin of New Zealand White rabbits.

Executive summary:

The dermal irritation potential of 4-methylpiperazin-1-amine was estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

4-methylpiperazin-1-amine was estimated to be irritating to the skin of New Zealand White rabbits.

Based on the estimated results,4-methylpiperazin-1-aminecan be considered to be irritating to skin and can be classified under the category “Category 2” as per CLP regulation.

 

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

data is from OECD QSAR toolbox v3.3 and the QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using OECD QSAR toolbox v3.3

GLP compliance:

not specified

Specific details on test material used for the study:

Name of the test chemical: 4-Methylpiperazin-1-amine
Molecular Formula: C5H13N3
Molecular Weight: 115.179 g/mol
InChI: 1S/C5H13N3/c1-7-2-4-8(6)5-3-7/h2-6H2,1H3
Substance Type: Organic
Physical State: Liquid

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

no data available

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.1ml

Duration of treatment / exposure:

single exposure

Observation period (in vivo):

72 hours

Duration of post- treatment incubation (in vitro):

no data available

Number of animals or in vitro replicates:

3

Details on study design:

no data available

Other effects / acceptance of results:

no data available

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

72 h

Reversibility:

not specified

Remarks on result:

positive indication of irritation

Irritant / corrosive response data:

Irritation was observed

Estimation method: Takes mode value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

((((((((("a" or "b" or "c" )  and "d" )  and ("e" and ( not "f") )  )  and "g" )  and ("h" and ( not "i") )  )  and ("j" and ( not "k") )  )  and ("l" and ( not "m") )  )  and ("n" and ( not "o") )  )  and ("p" and "q" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Aliphatic Amines by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Hydrazine Derivatives by DNA binding by OASIS v.1.3 ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SN1 OR SN1 >> Iminium Ion Formation OR SN1 >> Iminium Ion Formation >> Aliphatic tertiary amines by DNA binding by OECD ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Iminium Ion Formation AND SN1 >> Iminium Ion Formation >> Aliphatic tertiary amines by DNA binding by OECD ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Non binder, without OH or NH2 group by Estrogen Receptor Binding

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Non binder, impaired OH or NH2 group OR Non binder, MW>500 OR Non binder, non cyclic structure OR Strong binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OECD ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Basic [0,10) AND No pKa value by Ionization at pH = 9

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Acidic [0,10) OR Acidic [30,40) OR Acidic [80,90) OR Acidic [90,100] OR Basic [20,30) OR Basic [40,50) OR Basic [50,60) OR Basic [60,70) OR Basic [70,80) OR Basic [80,90) OR Basic [90,100] by Ionization at pH = 9

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Inclusion rules not met by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Esters of organic sulfonic or sulfuric esters OR Ketones by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Hydrazine AND Piperazine AND Saturated heterocyclic amine AND Saturated heterocyclic fragment by Organic Functional groups

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Urea derivatives by Organic Functional groups

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as No alert found by Respiratory sensitisation

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Pro-Schiff base formation OR Pro-Schiff base formation >> Pro-cross linking Schiff base OR Pro-Schiff base formation >> Pro-cross linking Schiff base >> Hexamine by Respiratory sensitisation

Domain logical expression index: "p"

Parametric boundary:The target chemical should have a value of log Kow which is >= -2.15

Domain logical expression index: "q"

Parametric boundary:The target chemical should have a value of log Kow which is <= -0.348

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

4-methylpiperazin-1-amine was estimated to be irritating to the eyes of New Zealand White rabbits.

Executive summary:

The ocular irritation potential of 4-methylpiperazin-1-amine was estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

4-methylpiperazin-1-amine was estimated to be irritating to the eyes of New Zealand White rabbits.

Based on the estimated results,4-methylpiperazin-1-amine can be considered to be irritating to eyes and can be classified under the category “Category 2” as per CLP regulation.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation:

In different studies, 4-methylpiperazin-1-amine has been investigated for potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits along with predicted data for target chemical and its structurally similar read across substances, 1-methylpiperazine [CAS: 109-01-3] and Methyldiethanolamine [CAS: 105-59-9].The predicted data using the OECD QSAR toolbox has also been compared with the experimental data.

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the dermal irritation potential was estimated for 4-methylpiperazin-1-amine. 4 -methylpiperazin-1-amine was estimated to be irritating to the skin of New Zealand White rabbits.

Skin irritation effects were also estimated by four different models i.e, Battery, Leadscope, SciQSAR and CASE Ultra used within Danish QSAR database for 4-Methylpiperazin-1-amine.Based on estimation, severe skin irritation effects were known when 4-Methylpiperazin-1-aminewas exposed to rabbit skin.Hence,4-Methylpiperazin-1-amine can be considered to be irritating to skin.

Both the estimated studies are in agreement with each other indicating the possibility of 4-Methylpiperazin-1-amine being irritating to skin.

These results are further supported by the experimental study summarized in American Industrial Hygiene Association Journal, 1962, 23:2, 95-107; for the structurally similar read across substance, 1-methylpiperazine [CAS: 109-01-3]. Primary skin irritation on rabbits was recorded in a 10-grade ordinal series and was based upon the severest reaction that develops on the clipped abdominal skin of each of five albino rabbits within 24 hours of the uncovered application of 0.01 ml of undiluted sample or of solutions in water, propylene glycol, or acetone. Grade 1 indicates no irritation and Grade 2 the least visible capillary injection from the undiluted chemical. Grade 6 indicates necrosis when undiluted and Grade 10 indicates necrosis from a 0.01% solution. Primary Irritation score after 24 hours for 1 -methyl piperazine was Grade 6.

Based on this grade, 1-methylpiperazine can be considered moderately irritating to rabbit skin.

These results are also supported by the experimental study summarized in The MAK Collection for Occupational Health and Safety, Volume 9, pg 292–294, 2012; for the structurally similar read across substance, Methyldiethanolamine [CAS: 105-59-9]. 0.01 ml (10 mg) of the undiluted substance was applied to the shaved skin of 5 albino rabbits under non occlusive conditions for 24 hours. The test site was observed for signs of irritation. Slight irritation was observed after 24 hours exposure to Methyldiethanolamine.

Hence, Methyldiethanolamine can be considered irritating to skin.

Based on the available data for the target as well as read across chemicals and applying the weight of evidence approach, 4-Methylpiperazin-1-amine can be considered irritating to skin.Comparing the above annotations with the criteria of CLP regulation, test chemical can be classified under the category “Category 2”.

Eye Irritation:                                                       

In different studies, 4-methylpiperazin-1-amine has been investigated for potential for ocular irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits along with predicted data for target chemical and its structurally similar read across substances, 2,2'-Dichloro-N-methyldiethylamine (Nitrogen Mustard) [CAS: 51-75-2], 1-methylpiperazine [CAS: 109-01-3] and Methyldiethanolamine [CAS: 105-59-9].The predicted data using the OECD QSAR toolbox has also been compared with the experimental data.

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the dermal irritation potential was estimated for 4-methylpiperazin-1-amine. 4 -methylpiperazin-1-amine was estimated to be irritating to the skin of New Zealand White rabbits.

This result is supported by the experimental study conducted by Yair Morad et.al (Invest Ophthalmol Vis Sci. 2005; 46:1640–1646) to assess the extent of ocular injury caused by the structurally similar read across substance, 2,2'-Dichloro-N-methyldiethylamine (Nitrogen Mustard) [CAS: 51-75-2] in rabbits. A total of 52 New Zealand Albino rabbits weighing 2.5 to 3.5 kg were used. All animal experiments were conducted in compliance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. One eye in each of 52 rabbits was exposed to 2% nitrogen mustard (NM).Eight eyes (four animals) that were not exposed to NM served as the control. Animals were anesthetized with ketamine HCl (Ketalar, 50mg/kg) injected intramuscularly in combination with the relaxing agent xylazine (0.5 mg/kg). Local anesthetic drops (benoxinate HCl 0.4) were administered. Briefly, NM (mechlorethamine), at a concentration of 2% in saline, was applied to the cornea of one eye of each animal (the experimental eye) for 5 minutes within a trephine. Immediately after application, NM was quickly absorbed from within the trephine with small Weck-cell sponges, followed by washing of the eye with copious amounts of normal saline. In control eyes (four additional animals, eight eyes), saline solution (instead of NM) was applied to the cornea for 5 minutes, also within the trephine. In control experiments, the vehicle (saline) was used as eye drops after exposure to NM. During the experiment and follow-up, intramuscular dipyrone injections (10 mg/kg) were given to animals showing pain or distress. Slit-lamp examinations were performed at 24 hours after exposure, and subsequently at days 4, 7, 10, 14, 17, 21, 25, and 29. In each examination, the following parameters were recorded: Area of corneal epithelial loss (corneal erosion), Degree of corneal opacity, Degree of iris pigmentation, Degree of corneal neo-vascularization (CNV). Exposure to NM causes severe and long-lasting injury to ocular anterior segment structures. Injury to the conjunctiva and cornea in a saline-administered eye 1 day after exposure to 2% NM was noted. Conjunctival and corneal injury, scarring, and neo-vascularization evolved over the entire duration of the experiment (4 weeks) in such eyes. Corneal Neo- vascularization developed to various degrees in all groups after exposure to NM. An increase in Intra Ocular Pressure occurred after exposure to NM, peaking at day 4 in all study groups. Exposure to NM caused iris atrophy and pigmentation together with pupil dilation in all study groups.

On the basis of these observations, we can consider Nitrogen mustard to be irritating to eyes.

These results are further supported by the experimental stud summarized in American Industrial Hygiene Association Journal, 1962, 23:2, 95-107; for the structurally similar read across substance, 1-methylpiperazine [CAS: 109-01-3]. Eye injury in rabbits was recorded in a 10- grade ordinal series and was based upon the degree of corneal necrosis that resulted from instillation of various volumes and concentrations of chemical. Grade 1 indicates at most a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye. Grade 5 indicates a so-called severe burn from 0.005 ml, and Grade 10 indicates a severe burn from 0.5 ml of a 1% solution in water or propylene glycol. Primary Eye Irritation score for 1-methyl piperazine was Grade 8. Based on the grade, 1-methyl piperazine was considered to be severely irritating to eyes.

These results are also supported by the experimental study summarized in The MAK Collection for Occupational Health and Safety, Volume 9, pg 292–294, 2012; for the structurally similar read across substance, Methyldiethanolamine [CAS: 105-59-9]. 50 microliters of the test chemical was instilled into eyes of rabbits and effects were observed for 8 days. Symptoms like redness, swelling and clouding of the cornea as well as conjunctival bleeding were observed in rabbits which were reversible after 8 days. Based on these observations, 2, 2’-(methylimino)bisethanol was severely irritating to rabbit eyes.

Based on the available data for the target as well as read across chemicals and applying the weight of evidence approach, 4-Methylpiperazin-1-amine can be considered irritating to eyes.Comparing the above annotations with the criteria of CLP regulation, test chemical can be classified under the category “Category 2”.

Justification for classification or non-classification

Available studies for 4-methylpiperazin-1-amine indicate that it is likely to cause irritation to skin and eyes.

Hence,4-methylpiperazin-1-amine can be classified under the category “CATEGORY 2” as per CLP regulation.