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Description of key information

Acute oral toxicity: 

Acute oral toxicity dose (LD50) of 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) was predicted based on OECD QSAR toolbox, the value was estimated to be 2160 mg/kg bw and different studies available for the structurally similar read across substances 4-hydroxyphenethyl ammonium chloride (CAS no: 60-19-5), the LD50 was considered to be >2000 mg/kg bw; and 4-ethylphenol (CAS no: 123-07-9), the LD50 was considered to be >2000 mg/kg bw. All these studies concluded that the LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 4-(2-Aminoethyl)phenol cannot be classified for acute oral toxicity.

Acute Inhalation toxicity: 

Acute Inhalation toxicity dose (LC50) for 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) was predicted based on OECD QSAR toolbox, the value was estimated to be 169 mg/L (169000 mg/m3) and different study available for the structurally similar read across substance 2-phenylethyl phenylacetate (CAS No.102-20-5), the LC50 value was considered to be >5 mg/L (>5000 mg/m3). Both these studies concluded that the LC50 value is >5 mg/L air. Thus, comparing this value with the criteria of CLP regulation, 4-(2-Aminoethyl) phenol cannot be classified for acute Inhalation toxicity.

Acute Dermal toxicity: 

Acute Dermal toxicity dose (LD50) for 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) was predicted based on OECD QSAR toolbox, the value was estimated to be 3044 mg/kg bw and different studies available for the structurally similar read across substances 4-methoxybenzyl alcohol (105-13-5), the LD50 was considered to be 3000 mg/kg bw; and 2-phenylethyl phenylacetate (CAS No. 102-20-5), the LD50 was considered to be >2000mg/kg bw. All these studies concluded that the LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 4-(2-Aminoethyl) phenol cannot be classified for acute dermal toxicity.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records
Reference
Endpoint:
acute toxicity: oral
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 predicted using OECD QSAR toolbox version 3.4 and the supporting QMRF report has been attached
Qualifier:
according to guideline
Guideline:
other: estimated data
Principles of method if other than guideline:
Prediction is done using QSAR Toolbox version 3.4
GLP compliance:
not specified
Test type:
other: not specified
Limit test:
no
Specific details on test material used for the study:
Name: 4-(2-Aminoethyl)phenol
SMILES:NCCc1ccc(O)cc1
InChI:1S/C8H11NO/c9-6-5-7-1-3-8(10)4-2-7/h1-4,10H,5-6,9H2
Mol. formula: C8H11NO
Molecular Weight: 137.1809 g/mole
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
not specified
Route of administration:
oral: gavage
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
not specified
Doses:
2160 mg/kg bw
No. of animals per sex per dose:
10
Control animals:
not specified
Details on study design:
not specified
Statistics:
not specified
Preliminary study:
not specified
Sex:
male/female
Dose descriptor:
LD50
Effect level:
2 160 mg/kg bw
Based on:
test mat.
Remarks on result:
other: 50% mortality was observed
Mortality:
not specified
Clinical signs:
other: not specified
Gross pathology:
not specified
Other findings:
not specified

The prediction was based on dataset comprised from the following descriptors: LD50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Primary amines by OECD HPV Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Aliphatic Amines AND Phenols (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Michael addition AND Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals AND Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Alkyl phenols by DNA binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Weak binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols by Protein binding by OASIS v1.4

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as No alert found by DNA binding by OASIS v.1.4

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as AN2 OR AN2 >>  Michael-type addition, quinoid structures OR AN2 >>  Michael-type addition, quinoid structures >> Quinoneimines OR AN2 >>  Michael-type addition, quinoid structures >> Quinones and Trihydroxybenzenes OR AN2 >> Carbamoylation after isocyanate formation OR AN2 >> Carbamoylation after isocyanate formation >> N-Hydroxylamines OR AN2 >> Nucleophilic addition reaction with cycloisomerization OR AN2 >> Nucleophilic addition reaction with cycloisomerization >> Hydrazine Derivatives OR AN2 >> Shiff base formation after aldehyde release OR AN2 >> Shiff base formation after aldehyde release >> Specific Acetate Esters OR Non-covalent interaction OR Non-covalent interaction >> DNA intercalation OR Non-covalent interaction >> DNA intercalation >> DNA Intercalators with Carboxamide and Aminoalkylamine Side Chain OR Non-covalent interaction >> DNA intercalation >> Quinones and Trihydroxybenzenes OR Radical OR Radical >> Generation of ROS by glutathione depletion (indirect) OR Radical >> Generation of ROS by glutathione depletion (indirect) >> Haloalkanes Containing Heteroatom OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Hydrazine Derivatives OR Radical >> Radical mechanism via ROS formation (indirect) >> N-Hydroxylamines OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitrophenols, Nitrophenyl Ethers and Nitrobenzoic Acids OR Radical >> Radical mechanism via ROS formation (indirect) >> Quinones and Trihydroxybenzenes OR Radical >> Radical mechanism via ROS formation (indirect) >> Single-Ring Substituted Primary Aromatic Amines OR Radical >> Radical mechanism via ROS formation (indirect) >> Thiols OR Radical >> ROS formation after GSH depletion (indirect) OR Radical >> ROS formation after GSH depletion (indirect) >> Quinoneimines OR SN1 OR SN1 >> Alkylation by carbenium ion formed OR SN1 >> Alkylation by carbenium ion formed >> Diazoalkanes OR SN1 >> Nucleophilic attack after carbenium ion formation OR SN1 >> Nucleophilic attack after carbenium ion formation >> Specific Acetate Esters OR SN1 >> Nucleophilic attack after nitrenium ion formation OR SN1 >> Nucleophilic attack after nitrenium ion formation >> N-Hydroxylamines OR SN1 >> Nucleophilic attack after nitrenium ion formation >> Single-Ring Substituted Primary Aromatic Amines OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitrophenols, Nitrophenyl Ethers and Nitrobenzoic Acids OR SN2 OR SN2 >> Acylation OR SN2 >> Acylation >> N-Hydroxylamines OR SN2 >> Acylation >> Specific Acetate Esters OR SN2 >> Alkylation OR SN2 >> Alkylation >> Alkylphosphates, Alkylthiophosphates and Alkylphosphonates OR SN2 >> Alkylation, direct acting epoxides and related OR SN2 >> Alkylation, direct acting epoxides and related >> Epoxides and Aziridines OR SN2 >> Alkylation, nucleophilic substitution at sp3-carbon atom OR SN2 >> Alkylation, nucleophilic substitution at sp3-carbon atom >> Haloalkanes Containing Heteroatom OR SN2 >> Direct acting epoxides formed after metabolic activation OR SN2 >> Direct acting epoxides formed after metabolic activation >> Quinoline Derivatives OR SN2 >> Direct nucleophilic attack on diazonium cation OR SN2 >> Direct nucleophilic attack on diazonium cation >> Hydrazine Derivatives OR SN2 >> Nucleophilic substitution at sp3 Carbon atom OR SN2 >> Nucleophilic substitution at sp3 Carbon atom >> Haloalkanes Containing Heteroatom OR SN2 >> Nucleophilic substitution at sp3 Carbon atom >> Specific Acetate Esters OR SN2 >> SN2 at an activated carbon atom OR SN2 >> SN2 at an activated carbon atom >> Quinoline Derivatives by DNA binding by OASIS v.1.4

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols by Protein binding by OASIS v1.4

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group >> Carboxylic Acid Amides OR Acylation >> Acylation involving an activated (glucuronidated) ester group OR Acylation >> Acylation involving an activated (glucuronidated) ester group >> Arenecarboxylic Acid Esters OR Acylation >> Direct acylation involving a leaving group OR Acylation >> Direct acylation involving a leaving group >> Carbamates  OR Acylation >> Direct acylation involving a leaving group >> Carboxylic Acid Amides OR Acylation >> Ester aminolysis OR Acylation >> Ester aminolysis >> Amides OR Acylation >> Ester aminolysis or thiolysis OR Acylation >> Ester aminolysis or thiolysis >> Carbamates  OR Acylation >> Ring opening acylation OR Acylation >> Ring opening acylation >> beta-Lactams  OR AN2 >> Michael addition to activated double bonds OR AN2 >> Michael addition to activated double bonds >> alpha,beta-Unsaturated Carbonyls and Related Compounds OR AN2 >> Michael addition to activated double bonds in heterocyclic ring systems OR AN2 >> Michael addition to activated double bonds in heterocyclic ring systems >> Pyrazolone and Pyrazolidine Derivatives OR AN2 >> Michael addition to alpha, beta-unsaturated acids and esters OR AN2 >> Michael addition to alpha, beta-unsaturated acids and esters >> alpha,beta-Unsaturated Carboxylic Acids and Esters OR AN2 >> Michael-type addition to quinoid structures  >> Carboxylic Acid Amides OR AN2 >> Michael-type addition to quinoid structures  >> Hydroxylated Phenols OR AN2 >> Schiff base formation with carbonyl compounds (AN2) OR AN2 >> Schiff base formation with carbonyl compounds (AN2) >> Pyrazolone and Pyrazolidine Derivatives OR Michael addition OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group >> alpha,beta-Carbonyl compounds with polarized double bonds  OR No alert found OR Nucleophilic addition OR Nucleophilic addition >> Addition to carbon-hetero double bonds OR Nucleophilic addition >> Addition to carbon-hetero double bonds >> Ketones OR Radical reactions OR Radical reactions >> ROS Generation OR Radical reactions >> ROS Generation >> Sterically Hindered Piperidine Derivatives OR Schiff base formation OR Schiff base formation >> Direct acting Schiff base formers OR Schiff base formation >> Direct acting Schiff base formers >> 1,2-Dicarbonyls and 1,3-Dicarbonyls  OR Schiff base formation >> Schiff base formation with carbonyl compounds OR Schiff base formation >> Schiff base formation with carbonyl compounds >> Aromatic carbonyl compounds OR Schiff base formation >> Schiff base on pyrazolones and pyrazolidinones OR Schiff base formation >> Schiff base on pyrazolones and pyrazolidinones >> Pyrazolones and Pyrazolidinones OR SN2 OR SN2 >> Interchange reaction with sulphur containing compounds OR SN2 >> Interchange reaction with sulphur containing compounds >> Thiols and disulfide compounds  OR SN2 >> Nucleophilic substitution on benzilyc carbon atom OR SN2 >> Nucleophilic substitution on benzilyc carbon atom >> alpha-Activated benzyls  OR SN2 >> SN2 Reaction at a sp3 carbon atom OR SN2 >> SN2 Reaction at a sp3 carbon atom >> Activated alkyl esters and thioesters  by Protein binding by OASIS v1.4

Domain logical expression index: "j"

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

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR SN2 OR SN2 >> SN2 reaction at sp3 carbon atom OR SN2 >> SN2 reaction at sp3 carbon atom >> Allyl acetates and related chemicals OR SNAr OR SNAr >> Nucleophilic aromatic substitution OR SNAr >> Nucleophilic aromatic substitution >> Activated halo-benzenes by Protein binding by OECD

Domain logical expression index: "l"

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

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Alkali Earth OR Halogens by Groups of elements

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Group 14 - Carbon C AND Group 15 - Nitrogen N AND Group 16 - Oxygen O by Chemical elements

Domain logical expression index: "p"

Referential boundary: The target chemical should be classified as Group 16 - Sulfur S by Chemical elements

Domain logical expression index: "q"

Similarity boundary:Target: NCCc1ccc(O)cc1
Threshold=50%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "r"

Similarity boundary:Target: NCCc1ccc(O)cc1
Threshold=80%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "s"

Parametric boundary:The target chemical should have a value of log Kow which is >= 0.769

Domain logical expression index: "t"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.55

Interpretation of results:
other: Not classified
Conclusions:
LD50 was estimated to be 2160 mg/kg bw, when 10 male and female Sprague-Dawley rats were treated with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) via oral gavage route.
Executive summary:

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 4-(2-Aminoethyl)phenol (CAS no: 51-67-2). The LD50 was estimated to be 2160 mg/kg bw, when 10 male and female Sprague-Dawley rats were treated with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) via oral gavage route.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
2 160 mg/kg bw
Quality of whole database:
Data is Klimisch 2 and from QSAR toolbox 3.4.

Acute toxicity: via inhalation route

Link to relevant study records
Reference
Endpoint:
acute toxicity: inhalation
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 predicted using OECD QSAR toolbox version 3.4 and the supporting QMRF report has been attached
Qualifier:
according to guideline
Guideline:
other: estimated data
Principles of method if other than guideline:
Prediction is done using QSAR Toolbox version 3.4
GLP compliance:
not specified
Test type:
other: not specified
Limit test:
no
Specific details on test material used for the study:
Name: 4-(2-Aminoethyl)phenol
SMILES:NCCc1ccc(O)cc1
InChI:1S/C8H11NO/c9-6-5-7-1-3-8(10)4-2-7/h1-4,10H,5-6,9H2
Mol. formula: C8H11NO
Molecular Weight: 137.1809 g/mole
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
not specified
Route of administration:
inhalation
Type of inhalation exposure:
nose/head only
Vehicle:
not specified
Remark on MMAD/GSD:
not specified
Details on inhalation exposure:
not specified
Analytical verification of test atmosphere concentrations:
not specified
Duration of exposure:
4 h
Remarks on duration:
not specified
Concentrations:
169 mg/L (169000 mg/m3)
No. of animals per sex per dose:
10
Control animals:
not specified
Details on study design:
not specified
Statistics:
not specified
Preliminary study:
not specified
Sex:
male/female
Dose descriptor:
LC50
Effect level:
169 mg/L air
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: 50% mortality was observed
Mortality:
not specified
Clinical signs:
other: not specified
Body weight:
not specified
Gross pathology:
not specified
Other findings:
not specified

The prediction was based on dataset comprised from the following descriptors: LC50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Primary amines by OECD HPV Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Aliphatic Amines AND Phenols (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Michael addition AND Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals AND Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Alkyl phenols by DNA binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Weak binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols by Protein binding by OASIS v1.4

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as No alert found by DNA binding by OASIS v.1.4

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as AN2 OR AN2 >> Carbamoylation after isocyanate formation OR AN2 >> Carbamoylation after isocyanate formation >> N-Hydroxylamines OR Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> N-Hydroxylamines OR Radical >> Radical mechanism via ROS formation (indirect) >> Single-Ring Substituted Primary Aromatic Amines OR SN1 OR SN1 >> Nucleophilic attack after nitrenium ion formation OR SN1 >> Nucleophilic attack after nitrenium ion formation >> N-Hydroxylamines OR SN1 >> Nucleophilic attack after nitrenium ion formation >> Single-Ring Substituted Primary Aromatic Amines OR SN2 OR SN2 >> Acylation OR SN2 >> Acylation >> N-Hydroxylamines by DNA binding by OASIS v.1.4

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as No superfragment by Superfragments ONLY

Domain logical expression index: "i"

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

Domain logical expression index: "j"

Similarity boundary:Target: NCCc1ccc(O)cc1
Threshold=20%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "l"

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

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Aliphatic Amine, secondary OR Aliphatic Amine, tertiary by Organic Functional groups

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "p"

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

Domain logical expression index: "q"

Referential boundary: The target chemical should be classified as Phenols by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "r"

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: "s"

Parametric boundary:The target chemical should have a value of log Kow which is >= 0.338

Domain logical expression index: "t"

Parametric boundary:The target chemical should have a value of log Kow which is <= 2.8

Interpretation of results:
other: Not classified
Conclusions:
LC50 was estimated to be 169 mg/L (169000 mg/m3), when 10 male and female Wistar rats were exposed with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) via inhalation route to nose/head only exposure for 4 h.
Executive summary:

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute inhalation toxicity was estimated for 4-(2-Aminoethyl)phenol (CAS no: 51-67-2). The LC50 was estimated to be 169 mg/L (169000 mg/m3), when 10 male and female Wistar rats were exposed with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) via inhalation route to nose/head only exposure for 4 h.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LC50
Value:
169 000 mg/m³ air
Quality of whole database:
Data is Klimisch 2 and from QSAR toolbox 3.4.

Acute toxicity: via dermal route

Link to relevant study records
Reference
Endpoint:
acute toxicity: dermal
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 predicted using OECD QSAR toolbox version 3.4 and the supporting QMRF report has been attached
Qualifier:
according to guideline
Guideline:
other: estimated data
Principles of method if other than guideline:
Prediction is done using QSAR Toolbox version 3.4
GLP compliance:
not specified
Test type:
other: not specified
Limit test:
no
Specific details on test material used for the study:
Name: 4-(2-Aminoethyl)phenol
SMILES:NCCc1ccc(O)cc1
InChI:1S/C8H11NO/c9-6-5-7-1-3-8(10)4-2-7/h1-4,10H,5-6,9H2
Mol. formula: C8H11NO
Molecular Weight: 137.1809 g/mole
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals or test system and environmental conditions:
not specified
Type of coverage:
occlusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
not specified
Duration of exposure:
24 hours
Doses:
3044 mg/kg bw
No. of animals per sex per dose:
10
Control animals:
not specified
Details on study design:
not specified
Statistics:
not specified
Preliminary study:
not specified
Sex:
male/female
Dose descriptor:
LD50
Effect level:
3 044 mg/kg bw
Based on:
test mat.
Remarks on result:
other: 50% mortality was observed
Mortality:
not specified
Clinical signs:
other: not specified
Gross pathology:
not specified
Other findings:
not specified

The prediction was based on dataset comprised from the following descriptors: LD50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Primary amines by OECD HPV Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Aliphatic Amines AND Phenols (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Michael addition AND Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals AND Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Alkyl phenols by DNA binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Weak binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols by Protein binding by OASIS v1.4

Domain logical expression index: "f"

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

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR SN2 OR SN2 >> Epoxides and Related Chemicals OR SN2 >> Epoxides and Related Chemicals >> Epoxides OR SN2 >> SN2 reaction at sp3 carbon atom OR SN2 >> SN2 reaction at sp3 carbon atom >> Alkyl halides by Protein binding by OECD

Domain logical expression index: "h"

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

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Alkali Earth OR Halogens OR Metalloids by Groups of elements

Domain logical expression index: "k"

Similarity boundary:Target: NCCc1ccc(O)cc1
Threshold=10%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as (!Undefined)Group All Lipid Solubility < 0.01 g/kg AND (!Undefined)Group CN Lipid Solubility < 0.4 g/kg by Skin irritation/corrosion Exclusion rules by BfR

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as (!Undefined)Group C Surface Tension > 62 mN/m OR (N/A) OR Group All Melting Point > 200 C OR Group C Melting Point > 55 C OR Group C Vapour Pressure < 0.0001 Pa OR Group CN Melting Point > 180 C OR Group CN Vapour Pressure < 0.001 Pa by Skin irritation/corrosion Exclusion rules by BfR

Domain logical expression index: "n"

Similarity boundary:Target: NCCc1ccc(O)cc1
Threshold=20%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "o"

Similarity boundary:Target: NCCc1ccc(O)cc1
Threshold=50%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "p"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "q"

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

Domain logical expression index: "r"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "s"

Referential boundary: The target chemical should be classified as Aliphatic Amine, tertiary by Organic Functional groups

Domain logical expression index: "t"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "u"

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

Domain logical expression index: "v"

Referential boundary: The target chemical should be classified as Aliphatic Amine, primary AND Aryl AND Phenol AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "w"

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

Domain logical expression index: "x"

Parametric boundary:The target chemical should have a value of log Kow which is >= 0.239

Domain logical expression index: "y"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.03

Interpretation of results:
other: Not classified
Conclusions:
LD50 was estimated to be 3044 mg/kg bw, when 10 male and female New Zealand White rabbits were treated with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) for 24 hours by dermal application occlusively.
Executive summary:

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for 4-(2-Aminoethyl)phenol (CAS no: 51-67-2). The LD50 was estimated to be 3044 mg/kg bw, when 10 male and female New Zealand White rabbits were treated with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) for 24 hours by dermal application occlusively.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
Value:
3 044 mg/kg bw
Quality of whole database:
Data is Klimisch 2 and from QSAR toolbox 3.4.

Additional information

Acute oral toxicity:

In different studies, 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats for 4-(2-Aminoethyl)phenol along with the study available on structurally similar read across substances 4-hydroxyphenethylammonium chloride (CAS no: 60-19-5) and 4-ethylphenol (CAS no: 123-07-9). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 4-(2-Aminoethyl)phenol (CAS no: 51-67-2). The LD50 was estimated to be 2160 mg/kg bw, when 10 male and female Sprague-Dawley rats were treated with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) via oral gavage route.

The above study is supported by Til et al.(Food and Chemical Toxicology, Volume 35, Issues 3–4, March–April 1997, Pages 337-348) and World Health Organization (WHO Food Additives Series No. 56, pg. 327-395, 2006), for the structurally similar read across substance 4-hydroxyphenethylammonium chloride (CAS no: 60-19-5). The oral toxicity study was conducted by in 20 male and femaleCpb:WU; Wistar random, SPF-bred rats at the dose concentration of 125 mg/kg, 250 mg/kg, 500 mg/kg , 1000 mg/kg and 2000 mg/kg bw. The given test chemical (purity 99%, obtained from E. Merck AG, Darmstadt, Germany) administered orally as a 25% aqueous dilution at various dose levels to groups of 2 male and 2 female rats.The exact amount of the test substances to be dosed in mg/kg was calculated for each animal and administered by gavage. The rats were observed for mortality and clinical signs for 14 days. The animals that died and the survivors killed after 14 days were examined for pathological changes. No mortality was observed at 2000 mg/kg bw. Most of the animals showed sluggishness and Piloerection. Exophthalmus was seen in the 1000 and 2000 mg/kg groups. Therefore, LD50 was considered to be >2000 mg/kg bw, when male and female Cpb:WU; Wistar random, SPF-bred rats were treated with 4-hydroxyphenethyl ammonium chloride via oral gavage route.

These studies are further supported by Ministry of Health, Labour and Welfare, Ministry of the Environment and National Institute of Technology and Evaluation (J-CHECK Japan Chemicals Collaborative Knowledge database, 2010) for the structurally similar read across substance 4-ethylphenol (CAS no: 123-07-9). The acute oral toxicity study was conducted according to OECD Guideline 401 in 10 male and female Sprague-Dawley (Crj: CD (SD) IGS) rats at the dose concentration of 2000 mg/kg bw. The given test chemical (purity: 98.3%, obtained from Maruzen Petrochemical Co., Ltd., Tokyo) was dissolved in olive oil and administered as a volume of 10 mL/kg via oral gavage route. Animals were observed immediately after administration on the administration day (0 day) until 1 hour after administration, observation was continued, and from 2 hours to 6 hours after administration was observed at about 1 hour intervals. From day 1 to day 14 post-administration, observation was carried out once a day until the autopsy day; and weighing: Animals were observed before administration on the administration day, 1, 3, 5, 7, 10 and 14 days after administration. Necropsy was performed. On the 14th day after administration, the external surface table was observed, then exsanguinated under etheranesthesia and killed, and the organs and tissues of the whole body were macroscopically observed. Animals were observed for clinical signs. No mortality was observed at 2000 mg/kg bw. In the 2000 mg/kg group, staggering walking occurred in about 10 to 20 minutes after administration in 3 males and 2 females, followed by 2 male and 1 female with prone or lying, and breathing Evidence was observed in 2 males and 1 female, respectively. Both of these symptoms recovered in 1 to 2 hours after administration. Thereafter, no abnormality was observed until 14 days after administration on the end date of the observation period. There was no significant difference in the amount and weight gain rate. Necropsy at 14 days after administration showed no abnormality in both sexes of 2000 mg/kg group. Therefore, LD50 was considered to be >2000 mg/kg bw, when 10 male and female Sprague-Dawley (Crj: CD (SD) IGS) rats were treated with 4-ethylphenol (CAS no: 123-07-9) via oral gavage route.

Thus, based on the above studies on 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) and it’s read across substances, it can be concluded that LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 4-(2-Aminoethyl)phenol cannot be classified for acute oral toxicity.

Acute Inhalation Toxicity:

In different studies, 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) has been investigated for acute Inhalation toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats for 4-(2-Aminoethyl) phenol along with the study available on structurally similar read across substance 2-phenylethyl phenyl acetate (CAS No.102-20-5). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute inhalation toxicity was estimated for 4-(2-Aminoethyl)phenol (CAS no: 51-67-2). The LC50 was estimated to be 169 mg/L (169000 mg/m3), when 10 male and female Wistar rats were exposed with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) via inhalation route to nose/head only exposure for 4 h.

The above study is supported by Sustainability Support Services (Europe) AB, (Company study No. 20167, 2012), was designed and conducted for the structurally similar read across substance 2-phenylethyl phenylacetate (CAS No.102-20-5). The acute inhalation toxicity study was conducted according to OECD Guideline 403 (Acute Inhalation Toxicity) in 10 (5 males and 5 females) Wistar rats at the concentration of 5 mg/L by inhalation: aerosol via nose only exposure. The aerosol was generated by the used of Nanotek aerosol generator (particle size less than 1 micron). All exposure was conducted in a dynamic nose-only cylindrical chamber built from stainless steel and glass. The chamber had a volume of 8 liters with inner and outer chamber to minimize the fluctuation in concentration and temperature. All the animals uniformly exposed to aerosol drug concentration. For the inhalation purpose the rats were placed in polycarbonate holder tubes positioned   radically around exposure chamber, so that only the snouts and nostrils of the animals were exposed to the aerosol. The chamber was maintained at a slightly negative pressure to prevent leakage of the test atmosphere from the system, as well as its dilution with outside air. The exhaust air was decontaminated by subsequent passage through 1% NaOH solution, silica gel and activated charcoal filters. In limit test, 10 healthy Wistar albino rats of both sex body weight 200±20 gm were selected for study after acclimatization. The test groups of animals were exposed to aerosol at the concentration of 5 mg/L for period of 4 hrs. After exposure all the animals were closely observed for any clinical signs of toxicity at various intervals such as 1 hr, 2 hrs, 4 hrs, and 6 hrs on the day of test compound aerosol exposure and later on twice a day throughout the experimentation period of 14 days. The necropsy was performed on all the animals at termination of experiment. All the albino rats exposed to aerosol at the concentration of 5 mg/L did not show any clinical signs of intoxication. Furthermore, no mortality was observed throughout the period of observation. After 72 hrs, the result obtained from limit test was confirmed in another 10 animal of both sex at similar concentration following same guideline. No mortality at the tested dose level of 5.0 mg/L throughout the period of observation after exposure. The test compound did not elicit any clinical signs of intoxication at the tested aerosol concentration of 5 mg/L observed for the period of 14 days. The body weight of all the animals recorded individually on day 7th and 14th (post treatment) showed normal gain as compared to day 0th. No gross pathological changes were observed. Therefore, LC50 was considered to be >5 mg/L (>5000 mg/m3), when male and female Wistar rats were exposed with 2-phenylethyl phenylacetate (CAS No.102-20-5) via inhalation route by nose only exposure for 4 hours.

Thus, based on the above studies on 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) and it’s read across substance, it can be concluded that LC50 value is >5 mg/L air. Thus, comparing this value with the criteria of CLP regulation, 4-(2-Aminoethyl) phenol cannot be classified for acute Inhalation toxicity.

Acute Dermal toxicity:

In different studies, 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments in rodents, i.e. most commonly in rabbits and rats for 4-(2-Aminoethyl) phenol along with the studies available on the structurally similar read across substances 4-methoxybenzyl alcohol (105-13-5) and 2-phenylethyl phenylacetate (CAS No. 102-20-5). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for 4-(2-Aminoethyl)phenol (CAS no: 51-67-2). The LD50 was estimated to be 3044 mg/kg bw, when 10 male and female New Zealand White rabbits were treated with 4-(2-Aminoethyl)phenol (CAS no: 51-67-2) for 24 hours by dermal application occlusively.

The above study is supported by D. L. J. Opdyke (Food and Cosmetics Toxicology, Volume 12, Issues 7–8, December 1974, Page 825), IFA GESTIS (GESTIS SUBSTANCE Database, 2017), Scognamiglio et al. (Food and Chemical Toxicology 50 (2012) S134–S139) and RTECS (registry of toxic effect of chemical substance data base, 2018), for the structurally similar read across substance 4-methoxybenzyl alcohol (105-13-5). Acute dermal toxicity study was conducted in rabbit at the concentration of 1250, 2500, and 5000 mg/kg bw. Animals were observed for clinical signs.Mortalities included 1 rabbit from the 2500 g/kg group on day 1, and all 4 rabbits from the 5000 mg/kg group by day 6.Clinical signs of toxicity included loss of coordination and muscle tone in 2 animals at 5000 mg/kg and 1 animal at 2500 mg/kg. Slight to moderate erythema and edema was also observed in all animals. Therefore, LD50 was considered to be 3000 mg/kg with 95% confidential limit of 1940-4060 mg/kg bw, when rabbit was treated with 4-methoxybenzyl alcohol by dermal application.

These studies are further supported by Sustainability Support Services (Europe) AB, (Report No. 14_49_096, 2014), for the structurally similar read across substance 2-phenylethyl phenylacetate (CAS No. 102-20-5). Acute Dermal Toxicity Study in Wistar Rats, was performed as per OECD No. 402. Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Rats free from injury and irritation of skin were selected for the study. Approximately, 24 hours prior to dermal application of test item, greater than 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight based on the test item density (1.07513) and latest body weight was applied by single dermal application and observed for 14 days after treatment. On test day 0, calculated volume of test item was applied directly on the intact skin of clipped area of rats; the porous gauze dressing was put on to the intact skin of clipped area. This porous gauze dressing was covered with a non-irritating tape. After the 24-hour application period, the dressings were removed and the skin was gently wiped with distilled water. The skin reactions were assessed. The animals were observed daily for mortality and clinical signs, during the acclimatization period and post dosing till the termination. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1-14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically. No mortality was observed in any animal till the end of the experimental period. At 2000 mg/kg, all the animals were observed normal throughout the experimental period. Mean body weight was observed with gain on day 7 and 14 of male and female animals, as compared to day 0. The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality. Hence The LD50 was considered to be >2000mg/kg bw, when rats were treated with 2-phenylethyl phenylacetate (CAS No. 102-20-5) by dermal application.

Thus, based on the above studies on 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) and it’s read across substance, it can be concluded that LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 4-(2-Aminoethyl) phenol cannot be classified for acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies and prediction on 4-(2-Aminoethyl) phenol (CAS no: 51-67-2) and it’s read across substances, it can be concluded that LD50 value is >2000 mg/kg bw for acute oral and dermal toxicity; and LC50 value is >5 mg/L air for acute inhalation toxicity. Thus, comparing these values with the criteria of CLP regulation, 4-(2-Aminoethyl) phenol cannot be classified for acute oral, dermal and inhalation toxicity.