4-amino-N-(4-aminophenyl)benzenesulphonamide

Endpoint summary

Description of key information

Acute oral toxicity: 

Acute oral toxicity dose (LD50) for 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) was determined by Sustainability Support Services (Europe) AB and the acute oral LD50 was calculated as 7100 (5504-9159) mg/kg bw. It was concluded that LD50 value is greater than 2000 mg/kg bw.Thus, acute toxicity study of 4-amino-N-(4-aminophenyl) benzenesulphonamide, when administered to Sprague-Dawley male and female rats falls into the “Category 5 (>2000)” as per criteria of CLP.

Acute Inhalation toxicity: 

Acute Inhalation toxicity dose (LC50) for 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) was determined by Sustainability Support Services (Europe) AB and the acute inhalation LC50 was calculated as >5.2 mg/L air. It was concluded that LC50 value is greater than 5 mg/L air.Thus, acute toxicity study of 4-amino-N-(4-aminophenyl) benzenesulphonamide, when treated in Wistar male/femaleratsfor 4 hoursfalls into the “Category 5” as per criteria of CLP.

Acute Dermal toxicity: 

Acute Dermal toxicity dose (LD50) for 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) was predicted based on OECD QSAR toolbox 4506 mg/kg bwand differentstudies available on structurally similar read across substance6-aminonaphthalene-2-sulphonic acid (CAS No. 93-00-5)>2000 mg/kg bw and 4,4'-Diamino diphenyl sulfone (80-08-0) >4000 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-amino-N-(4-aminophenyl)benzenesulphonamide can be classified as category V of 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:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Justification for type of information:

Data is from study report.

Qualifier:

according to guideline

Guideline:

other: as metioned below

Principles of method if other than guideline:

Acute oral toxicity test of 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) in Rat.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Specific details on test material used for the study:

Name - 4-amino-N-(4-aminophenyl)benzenesulphonamide
InChI - 1S/C12H13N3O2S/c13-9-1-3-10
(4-2-9)15-11-5-7-12(8-6-11)18(14,16)17/h1-8,15H,13H2,(H2,14,16,17)
Smiles - O=S(=O)(c1ccc(cc1)Nc1ccc(cc1)N)N
Mol. formula: C12H13N3O2S
Molecular Weight - 263.32 g/mole
Purity - 90-95%

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF-breeding: Company WIGA, Sulzfeld
- Weight at study initiation: male animals -222 g, female animals -182 g
- Diet (e.g. ad libitum): The rats received Altromin-R ad libitum
- Water (e.g. ad libitum):ad libitum

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 10000, 6400, 3200 and 1600 mg/kg
- Amount of vehicle (if gavage): The product was administered once in different doses as 16 and 20 % aqueous suspension (w / v) with carboxymethylcellulose through the gavage
MAXIMUM DOSE VOLUME APPLIED: 10000mg/kg

Doses:

10000, 6400, 3200 and 1600 mg/kg

No. of animals per sex per dose:

Total = 20 (Male/Female)

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality was observed at 1, 24 and 48 h as well as after 7 and 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: Animals were observed for symptoms of intoxication, macroscopical examination.

Statistics:

The median lethal dose (LD50) was calculated according to LITCHFIELD and WILCOXON.

Preliminary study:

No data

Sex:

male/female

Dose descriptor:

LD50

Effect level:

7 100 mg/kg bw

Based on:

test mat.

95% CL:

5 504 - 9 159

Remarks on result:

other: 50% mortality observed

Mortality:

At 6400 mg/kg - Female: 1/5 died at 48 hours and 3/5 died at 7 days; Male: 1/5 died at 48 hours.
At 10000 mg/kg - Female: 1/5 died at 24 hours, 4/5 at 48 hours and 5/5 at 7 days period; Male: 2/5 died at 24 hours, 3/5 died at 48 hours and 3/5 died at 7 days period.

Clinical signs:

other: Symptoms of poisoning such as dyspnea, apathy, bitten tails, dark yellow urin, calm behavior, slight tumbling was observed in animals.

Gross pathology:

In Died animals - acute stasis hyperemia, acute cardiac dilation, Liver clay gray, a bit bright Kidneys were observed.
In Killed animals - Internal organs were found without any pathological findings after macroscopic examination.

Other findings:

No data

Table - Mortality

Dose mg/kg	Conc. %	Animal number	dies within
			1 Hour	24 Hours	48 Hours	7 Days	14 Days
10000	20	5 M 5 F	0/5 0/5	2/5 1/5	3/5 4/5	3/5 5/5	3/5 5/5
6400		5 M 5 F	0/5 0/5	1/5 0/5	1/5 1/5	1/5 3/5	1/5 3/5
3200		5 M 5 F	0/5 0/5	0/5 0/5	0/5 0/5	0/5 0/5	0/5 0/5
1600	16	5 M 5 F	0/5 0/5	0/5 0/5	0/5 0/5	0/5 0/5	0/5 0/5

 

LD 50: 7100 (5504 - 9159) mg/kg

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

The LD50 was considered to be 7100 mg/kg bw with the confidential limit of 5504 – 9159mg/kg, when Sprague-Dawley male and female rats were treated with 4-amino-N-(4-aminophenyl)benzenesulphonamide via oral gavage route.

Executive summary:

The acute oral toxicity of 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) was tested in Sprague-Dawley male and female rat at the dose concentration of 10000, 6400, 3200 and 1600 mg/kg bw at 16 and 20 % aqueous suspension (W / v) with Carboxymethylcellulose. The test substance (90-95%) was applied through the gavage route. The animals was taken from SPF-breeding:Company WIGA,Sulzfeld of body weight-male animals 222g and female animals-182g. The rats received Altromin-R from the company Altrogge, Lage / Lippe, and water ad libitum. Mortality was observed at 1, 24 and 48 h as well as after 7 and 14 days. Animals were observed for symptoms of intoxication, macroscopical examination.The median lethal dose (LD50) was calculated according to LITCHFIELD and WILCOXON.50% mortality observed at 7100(5504-9159) mg/kg bw. Symptoms of poisoning such as dyspnea, apathy, bitten tails, dark yellow urin, calm behavior, slight tumbling was observed in animals. In Died animals - acute stasis hyperemia, acute cardiac dilation, Liver clay gray, a bit bright Kidneys were observed. In Killed animals - Internal organs were found without any pathological findings after macroscopic examination.Therefore, LD50 was considered to be 7100 mg/kg bw with the confidential limit of 5504 – 9159mg/kg, when Sprague-Dawley male and female rats were treated with 4-amino-N-(4-aminophenyl)benzenesulphonamide via oral gavage route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

7 100 mg/kg bw

Quality of whole database:

Data is Klimisch 2

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

To obtain quantitative animal data in order to assess a possible hazard by inhalation of the product

GLP compliance:

not specified

Test type:

other: Acute Inhalation Toxicity

Limit test:

no

Specific details on test material used for the study:

Name - 4-amino-N-(4-aminophenyl)benzenesulphonamide
InChI - 1S/C12H13N3O2S/c13-9-1-3-10
(4-2-9)15-11-5-7-12(8-6-11)18(14,16)17/h1-8,15H,13H2,(H2,14,16,17)
Smiles - O=S(=O)(c1ccc(cc1)Nc1ccc(cc1)N)N
Mol. formula: C12H13N3O2S
Molecular Weight - 263.32 g/mole
Purity - approx. 98% (dry substance)
Physical state /appearance : crystalline powder/brown
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 8/86
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions:Stability was ensured for 2 years under normal conditions

Species:

rat

Strain:

other: SPF Wistar/Chbb :THOM

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr . K . Thomae GmbH, D-7950 Biberach, FRG
- Age at study initiation: approx . 8- 9 weeks
- Weight at study initiation: male - 277 ± 4 .6 g, female - 191 ± 6.8 g
- Fasting period before study:
- Housing:housed in groups of five in cages type D III of Becker, without bedding
- Diet (e.g. ad libitum): KLIBA rat/mouse laboratory diet A 343 10 mm pellets,ad libitum
- Water (e.g. ad libitum):drinking water ad libitum
ENVIRONMENTAL CONDITIONS
- Temperature (°C): range of 20-24°C
- Humidity (%): range of 30-709%
- Air changes (per hr): central air-conditioning system
- Photoperiod (hrs dark / hrs light): light/dark rhythm of 12 hours.
IN-LIFE DATES: From:Aug 19, 1986 to Sept 2, 1986.

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

6.1 µm

Geometric standard deviation (GSD):

2

Remark on MMAD/GSD:

No data

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:glass-steel construction
- Exposure chamber volume: volume V~ 551
- Method of holding animals in test chamber:The animals were restrained in tubes and their snouts projected into the inhalation chamber.
- Source and rate of air: A dust aerosol was generated by means of a vibration dust
partitioning equipment
- Method of conditioning air:The supply air was conditioned via a central air-conditioning
system in such a way that there was a temperature of 19 - 25°C in the exposure apparatus.
- System of generating particulates/aerosols: Vacuum compressed air pump (Millipore) XX 60 220 5 0
- Method of particle size determination: Andersen Stack Sampler Mark II I

TEST ATMOSPHERE
- Brief description of analytical method used: The preweighed filter was placed into the filtration equipment. By means of a vacuum compressed air pump a volume of the dust aerosol was drawn through the filter. The dust concentration in mg/1 was calculated from the difference between the preweight of the filter and the weight of the filter after sampling, with reference to the sample volume of the inhalation atmosphere .

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Remarks on duration:

No data

Concentrations:

5.2 mg/L

No. of animals per sex per dose:

Total = 10

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The body weight of the animals was checked before the beginning of the test, after 7 days and at the end of the observation period. Clinical findings were recorded several times during exposure and at least once on each workday in the observation period . A check for dead animals was made daily.
- Necropsy of survivors performed: yes
- Other examinations performed: Animals were observed for clinical signs, body weight,organ weights, histopathology examinations.

Statistics:

The statistical evaluation of the concentration/effect relationship was carried out on the basis of the binomial test (Wittig, H . : Mathematische Statistik 1974, pp . 32 -35) in accordance with tables of the BASF Computer Center.

Preliminary study:

No data

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.2 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: No mortality was observed

Mortality:

No mortality was observed at 5.2 mg/L air.

Clinical signs:

other: During and after exposure, animals were accelerated to irregular breathing; and as of day 1 of the observation period, no abnormalities were detected in the animals of the test group.

Body weight:

The body weight gain of male and female rats was observed.

Gross pathology:

No abnormalities detected in male and female rats.

Other findings:

No data

Table – 1. Concentration and lethality

The mean of the concentration in the test group and the lethality rates (number of animals that died / number of animals exposed) are presented in the following table –

Cumulated lethality on day	Test group (concentration ) 1 (5 .2 mg/1 )
	M	F
0	0/5	0/5
1	-	-
2	-	-
7	-	-
14	-	-
Total at end of the study	0/10

 

m = male, f = femal e

- = lethality unchanged

0 = day of exposure

 

Table – 2. Body weight

Mean body weight	Before the study		After 7 days		After 14 days
	Male	Female	Male	Female	Male	Female
Test group 1 weight in gm number of animals	277   5	191   5	296   5	198   5	321   5	208   5
Historical (air) control Weight in gm	248	177	285	196	317	210

 

The body weight gain of male and female rats in the test group 1, compared with a historical control collective, was not affected by the substance over the total observation period. 

 

Table – 3. Results of analytical measurements - Concentration measurements

Test group 1

Sample No	Analyt . concentration mg/L
1	4.63
2	5.12
3	4.82
4	5.34
5	5.59
6	5.40
7	4.86
8	5.55
Mean	5.2
Standard deviation of the mean	± 0.36
Nominal concentration	47. 5

 

Table – 4. The particle size analysis of the test group led to the following results:

Stage	EACD 50% (µm)	mg	Percentage distribution	Cumulative distribution in %
Pre-impactor	26.6	42.1
Cascade impactor
0	29.5	0.06	1.6	98.4
1	18.2	0.09	2.3	96.1
3	8.5	0.99	25.6	70.5
4	5.5	1.25	32.4	38.1
5	2.8	1.07	27.7	10.4
7	1.2	0.35	9.1	1.3
Backup filter	< 1.2	0.05	1.3
Σ = 3.86			100	-

 

	mass (mg)
Pre-impactor Cascade impactor wall losses	42. 1 3. 86 30. 4

 

The MMAD 50% = 6 .1 um

(Geometrical standard deviation = 2 .0) was calculated from the results of the particle size analysis.

A respirable dust fraction that might reach the alveoli of 70.5 % was obtained from the results of the particle size analysis.

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

The acute inhalation toxicity study in Wistar male/female rat by using 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) for exposure of 4 hr was considered to be >5.2 mg/L air.

Executive summary:

The acute inhalation toxicity study was conducted based on the OECD Guidelines, method 403 on 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) in Wistar male/female rat at the concentration of 5.2 mg/L air. 5 male and 5 female rats were used for the test group.Head-nose inhalation system INA 20 (glass-steel construction, BASF Aktiengesellschaft, volume V  ̴ 55 1) the animals were restrained in tubes and their snouts projected into the inhalation chamber.A dust aerosol was generated by means of a vibration dust partitioning equipment. The supply air was conditioned via a central air-conditioning system in such a way that there was a temperature of 19 - 25°C in the exposure apparatus.The inhalation mixture was offered to the animals for inhalation for 4 hours.8y means of an exhaust air system the pressure ratios in the inhalation system were adjusted in such a way that the amount of exhaust air was about 10% lower (excess pressure). The nominal concentration was calculated from the amount of substance consumed and the air flow. 30 minutes after the beginning of the test at the earliest, one sample was taken from the test group for the particle size analysis. After the exposure period the animals were observed for 14 days. The body weight of the animals was checked before the beginning of the test, after 7 days and at the end of the observation period. Clinical findings were recorded several times during exposure and at least once on each workday in the observation period. A check for dead animals was made daily.Animals were observed for clinical signs, body weight, organ weights, histopathology examinations. The statistical evaluation of the concentration/effect relationship was carried out on the basis of the binomial test (Wittig, H. : Mathematische Statistik 1974, pp . 32 -35) in accordance with tables of the BASF Computer Center. No mortality was observed at 5.2 mg/L air. During and after exposure, animals were accelerated to irregular breathing; and as of day 1 of the observation period, no abnormalities were detected in the animals of the test group. The body weight gain of male and female rats was observed.No abnormalities detected in male and female rats. Therefore, LC50 was considered to be>5.2 mg/L air,when Wistar male/female rat was treated with 4-amino-N-(4-aminophenyl)benzenesulphonamide by inhalation for 4 hours.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 200 mg/m³ air

Quality of whole database:

Data is Klimisch 2

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

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-Amino-N-(4-aminophenyl)benzenesulphonamide
InChI:1S/C12H13N3O2S/c13-9-1-3-10(4-2-9)15-11-5-7-12(8-6-11)18(14,16)17/h1-8,15H,13H2,(H2,14,16,17)
SMILES:O=S(=O)(c1ccc(cc1)Nc1ccc(cc1)N)N
Molecular Weight: 263.32 g/mole
Molecular Formula:C12H13N3O2S

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:

not specified

Details on dermal exposure:

not specified

Duration of exposure:

24 hours

Doses:

4506 mg/kg

No. of animals per sex per dose:

not specified

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:

4 506 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 ("k" and ( not "l") )  )  and ("m" and "n" )  )

Domain logical expression index: "a"

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

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Primary aromatic amine by DNA binding by OECD

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Strong binder, NH2 group by Estrogen Receptor Binding

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group AND Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group >> Arenesulfonamides AND AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Anilines AND AN2 >> Nucleophilic addition at polarized N-functional double bond AND AN2 >> Nucleophilic addition at polarized N-functional double bond >> Arenesulfonamides by Protein binding by OASIS v1.4

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Amides AND Anilines (Unhindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Primary aromatic amine by DNA binding by OECD

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as No alert found OR SN1 >> Nitrenium Ion formation >> Aromatic nitro by DNA binding by OECD

Domain logical expression index: "h"

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

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Group 17 - Halogens Cl OR Group 17 - Halogens F,Cl,Br,I,At by Chemical elements

Domain logical expression index: "j"

Similarity boundary:Target: Nc1ccc(NS(=O)(=O)c2ccc(N)cc2)cc1
Threshold=40%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Aniline AND Aryl AND Sulfonamide by Organic Functional groups

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Benzothiazole/ Benzoisothiazole by Organic Functional groups

Domain logical expression index: "m"

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

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.62

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

LD50 was estimated to be 4506 mg/kg bw, when New Zealand White male and female rabbit was treated with 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) for 24 hours by dermal application occlusively.

Executive summary:

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for 4-amino-N-(4-aminophenyl) benzenesulphonamide (16803-97-7). The LD50 was estimated to be 4506 mg/kg bw, when New Zealand White male and female rabbit was treated with 4-amino-N-(4-aminophenyl) benzenesulphonamide for 24 hours by dermal application occlusively.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 506 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from QSAR toolbox 3.4

Additional information

Acute oral toxicity:

In an experimental study conducted by Sustainability Support Services (Europe) AB (study no.XXIII/98, 1974)was designed and conducted to determine the acute oral toxicity profile of 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) in Sprague-Dawley male and female rat at the dose concentration of 10000, 6400, 3200 and 1600 mg/kg bw at 16 and 20 % aqueous suspension (W / v) with Carboxymethylcellulose. The test substance (90-95%) was applied through the gavage route. The animals was taken from SPF-breeding: Company WIGA, Sulzfeld of body weight-male animals 222g and female animals-182g. The rats received Altromin-R from the company Altrogge, Lage / Lippe, and water ad libitum. Mortality was observed at 1, 24 and 48 h as well as after 7 and 14 days. Animals were observed for symptoms of intoxication, macroscopical examination. The median lethal dose (LD50) was calculated according to LITCHFIELD and WILCOXON.50% mortality observed at 7100 (5504-9159) mg/kg bw. Symptoms of poisoning such as dyspnea, apathy, bitten tails, dark yellow urin, calm behavior, slight tumbling was observed in animals. In Died animals - acute stasis hyperemia, acute cardiac dilation, Liver clay gray, a bit bright Kidneys were observed. In Killed animals - Internal organs were found without any pathological findings after macroscopic examination. Therefore, LD50 was considered to be 7100 mg/kg bw with the confidential limit of 5504 – 9159mg/kg, when Sprague-Dawley male and female rats were treated with 4-amino-N-(4-aminophenyl)benzenesulphonamide via oral gavage route. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that 4-amino-N-(4-aminophenyl)benzenesulphonamide falls into the “Category 5” which is relatively nontoxic.

Acute Inhalation toxicity: 

In an experimental study conducted by Sustainability Support Services (Europe) AB (study no.kli-db/172, 1986)was designed and conducted to determine the acute inhalation toxicity profile of 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) based on the OECD Guidelines, method 403 in Wistar male/female rat at the concentration of 5.2 mg/L air. 5 male and 5 female rats were used for the test group. Head-nose inhalation system INA 20 (glass-steel construction, volume V   ̴ 55 1) the animals were restrained in tubes and their snouts projected into the inhalation chamber. A dust aerosol was generated by means of a vibration dust partitioning equipment. The supply air was conditioned via a central air-conditioning system in such a way that there was a temperature of 19 - 25°C in the exposure apparatus. The inhalation mixture was offered to the animals for inhalation for 4 hours. By means of an exhaust air system the pressure ratios in the inhalation system were adjusted in such a way that the amount of exhaust air was about 10% lower (excess pressure). The nominal concentration was calculated from the amount of substance consumed and the air flow. 30 minutes after the beginning of the test at the earliest, one sample was taken from the test group for the particle size analysis. After the exposure period the animals were observed for 14 days. The body weight of the animals was checked before the beginning of the test, after 7 days and at the end of the observation period. Clinical findings were recorded several times during exposure and at least once on each workday in the observation period. A check for dead animals was made daily. Animals were observed for clinical signs, body weight, organ weights, and histopathology examinations. The statistical evaluation of the concentration/effect relationship was carried out on the basis of the binomial test (Wittig, H.: Mathematische Statistik 1974, pp. 32 -35) in accordance with tables of the BASF Computer Center. No mortality was observed at 5.2 mg/L air. During and after exposure, animals were accelerated to irregular breathing; and as of day 1 of the observation period, no abnormalities were detected in the animals of the test group. The body weight gain of male and female rats was observed. No abnormalities detected in male and female rats. Therefore, LC50 was considered to be >5.2 mg/L air, when Wistar male/female rat was treated with 4-amino-N-(4-aminophenyl)benzenesulphonamide by inhalation for 4 hours. Thus, by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that 4-amino-N-(4-aminophenyl)benzenesulphonamide falls into the “Category 5” which is relatively nontoxic.

Acute Dermal toxicity:

In different studies, 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) 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 for 4-amino-N-(4-aminophenyl)benzenesulphonamide along with the study available on structurally similar read across substance 6-aminonaphthalene-2-sulphonic acid (CAS No. 93-00-5) and 4,4'-Diamino diphenyl sulfone (80-08-0). 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 (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for 4-amino-N-(4-aminophenyl) benzenesulphonamide (16803-97-7). The LD50 was estimated to be 4506 mg/kg bw, when New Zealand White male and female rabbit was treated with 4-amino-N-(4-aminophenyl) benzenesulphonamide for 24 hours by dermal application occlusively.

This study is supported bySustainability Support Services (Europe) AB (study no.19167, 2017), for the structurally similar read across substance 6-aminonaphthalene-2-sulphonic acid (CAS No. 93-00-5).The study was designed and conducted to determine the acute dermal toxicity profile in Sprague Dawley rats. The test item was applied to shorn skin of 5 male and 5 female animals at 2000 mg/kg body weight. Administration of the test item at 2000 mg/kg did not result in any skin reaction at the site of application during the study period of 14 days. Administration of the test item did not result in any signs of toxicity and mortality during the study period of 14 days. Animals exhibited normal body weight gain through the study period of 14 days. Gross pathological examination did not reveal any abnormalities attributable to the treatment. It was concluded that the acute dermal median lethal dose (LD50) of 6-aminonaphthalene-2-sulphonic acid (CAS No. 93-00-5), when administered to male and female Sprague Dawley rats was found to be >2000 mg/kg body weight. Thus, according to CLP criteria for acute toxicity rating for the chemicals, it infers that 6-aminonaphthalene-2-sulphonic acid (CAS No. 93-00-5) does not classify as an acute dermal toxicant. CLP Classification: “Unclassified”.

The above study is further supported by Charles et al. (Toxicology and Applied Pharmacology Volume 28, Issue 2, May 1974, Pages 313–319) and GESTIS SUBSTANCE Database (2017), for thestructurally similar read across substance4,4'-Diamino diphenyl sulfone (80-08-0). Acute Dermal toxicity study was conducted in rabbits at the concentration of 4000 mg/kg bw. No Mortality observed at 4000 mg/kg. Therefore, LD50 was considered to be >4000 mg/kg bw, when rabbits were treated with 4,4'-Diamino diphenyl sulfone by dermal application to the skin.

Thus, based on the above studies on 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) and it’s read across substances, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 4-amino-N-(4-aminophenyl)benzenesulphonamide can be classified as category V of acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies and prediction on 4-amino-N-(4-aminophenyl)benzenesulphonamide (16803-97-7) and it’s read across substances, it can be concluded that LD50 value is greater than 2000 mg/kg bw for acute oral and dermal toxicity and LC50 value is greater than 5 mg/L air. Thus, comparing this value with the criteria of CLP regulation, 4-amino-N-(4-aminophenyl)benzenesulphonamide can be classified as category V for acute oral, dermal and inhalation toxicity.