2-nitro-p-phenylenediamine

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as below

Principles of method if other than guideline:

The LLNA test for 2-nitro-p-phenylenediamine was conducted on groups of CBA mice

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALSSource: No dataAge at study initiation: 7-12 weeksENVIRONMENTAL CONDITIONS: No data

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

25 µl

No. of animals per dose:

No data

Details on study design:

The LLNA was conducted on groups of CBA mice (7-12 weeks of age) were exposed topically on the dorsum of both ears to 25µl of the test material or to an equal volume of relevant vehicle only. Treatment was performed daily for 3 consecutive days. Five days after initiation of exposure all mice were injected via the tail vein with 250µl of PBS containing 20µCi of tritiatied thymidine. The mice were sacrificed 5 hours later, and draining the auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by β-scintillation counting and was reported in disintegrations /minute. An SI was calculated for each chemical group as the ratio of disintegrations/minute of the treated group to the disintegrations/minute of the concurrent vehicle control group. A substance was classified skin sensitizer , if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3) The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value

Positive control substance(s):

not specified

Parameter:

other: Migrated information from in vivo LLNA study

Remarks on result:

other: Reading: other: EC3 = 0.4. Dose level: No data available.. Clinical observations: Strong sensitization was observed..

Parameter:

SI

Remarks on result:

other: EC3 = 0.4The relative potency index of 2NPPD was estimated to be 0.4.

Interpretation of results:

sensitising

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Conclusions:

The LLNA was conducted on groups of CBA mice (7-12 weeks of age) were exposed topically on the dorsum of both ears to 25µl of the test material or to an equal volume of relevant vehicle only. The relative potency index (EC3) of 2NPPD was estimated to be 0.4.Based on the relative potency index it is classified as a strong sensitizer

Executive summary:

The LLNA was conducted on groups of CBA mice (7-12 weeks of age) were exposed topically on the dorsum of both ears to 25µl of the test material or to an equal volume of relevant vehicle only. Treatment was performed daily for 3 consecutive days. Five days after initiation of exposure all mice were injected via the tail vein with 250µl of PBS containing 20µCi of tritiatied thymidine. The mice were sacrificed 5 hours later, and draining the auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by β-scintillation counting and was reported in disintegrations /minute. An SI was calculated for each chemical group as the ratio of disintegrations/minute of the treated group to the disintegrations/minute of the concurrent vehicle control group. A substance was classified skin sensitizer , if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3)

 

The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value

 

 The relative potency index of 2NPPD was estimated to be 0.4.

Based on the relative potency index it is classified as a strong sensitizer

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin sensitization

In the supporting study (Contact Dermatitis. 1992 Feb; 26(2):101-7.)skin sensitisation potential of 2-nitro-p-phenylenediamine was tested in humans.A multicenter study was performed in 9 Italian centers by members of the GIRDCA' to evaluate the frequency and source of contact sensitization in a group of 302 hairdressers with dermatitis.Occupational habits and use of preventive measures were specifically investigated both in these 302 hairdressers. The results showed the presence of an occupationally relevant sensitization in 60.9% of the 302 hairdressers

 Positive reactions to 2 NPPD occurred in 24 reactions (7.9%) 2NPPD appears to be a sensitizer compared to other hair dyes tested

The LLNA test ( Gerberick, et al, 2005) was conducted on groups of CBA mice (7-12 weeks of age) were exposed topically on the dorsum of both ears to 25µl of the test material or to an equal volume of relevant vehicle only. Treatment was performed daily for 3 consecutive days. Five days after initiation of exposure all mice were injected via the tail vein with 250µl of PBS containing 20µCi of tritiatied thymidine. The mice were sacrificed 5 hours later, and draining the auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by β-scintillation counting and was reported in disintegrations /minute. An SI was calculated for each chemical group as the ratio of disintegrations/minute of the treated group to the disintegrations/minute of the concurrent vehicle control group. A substance was classified skin sensitizer , if at one or more than one concentrations, it induced a three-fold or greater increase in local lymph node proliferative activity when treated with the concurrent vehicle treated controls (SI ≥3).The approach to estimation of the relative skin sensitization potential is based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value.The relative potency index of 2NPPD was estimated to be 0.4, based on which it is classified as a strong sensitizer

In the supporting study (Journal Of The American College Of Toxicology, 1985), skin sensitisation potential of 2-nitro-p-phenylenediamine was tested using Guinea pig maximisation test.20 guinea pigs received topical applications of 3 percent 2NPPD in an aqueous solution containing 2 percent Natrosol250 HR, 2 percent Tween 80, 0.05 percent sodium sulfite, and 10 percent isopropanol, and adjusted to pH 7.The compounds were applied daily 6 days a week for 3 weeks on a 6 cm²shaved area of the flank. A 2-week rest period was followed by application of the compounds on the opposite, previously untreated flanks of the guinea pigs. Four of 20 guinea pigs were sensitized to 2NPPD; the total reaction intensity for all the animals was 4 (scores added for all animals; possible total of 60).The researchers stated that 2NPPD produced a “weak reaction” . Therefore,2 NPPD can be considered as weakly sensitizing to Guinea pigs.

in the supporting study (Skin Research, Vol. 27, No. 3, June 1985, pp 585-590) skin sensitisation potential of 2-nitro-p-phenylenediamine was tested in guinea pigs. 2 nitro p phenylenediamine was tested for skin sensitization potency in guinea pigs.10, 5, 2, 1, 0.5, 0.2, and 0.1% concentration of each chemical was incorporated in white petrolatum. The test samples were occluded for 48 hours on the flanks of 10 Hartley albino guinea pigs.For induction, a 1% concentration of a test material in white petrolatum (about 50mg) was occluded for 48 hours on the nape. This procedure was repeated three times per week for two weeks. The induction phase was followed by a two-week rest period. At the end of the rest period, challenge concentrations of 1.0 - 0.01% of each test material were occluded on the animal's flanks for 48 hours. Readings were made at 24 and 48 hours after removal of the test material.The 10% and 0.1% concentrations of 2-nitro p phenylenediamine did not produce any irritant reactions.The frequency of sensitization (80% ) to2-nitro-p phenylenediamine was highest at 1% test concentration

Hence 2 nitro p phenylenediamine is a strong skin sensitizer in guinea pigs. In the supporting study (Skin Research, Vol. 27, No. 4, August 1985, pp 823-830)

skin sensitisation potential of 2-nitro-p-phenylenediamine was tested in humans.From 1974 to 1984, 24 hairdressers and 8 barbers were patch tested under the diagnosis of occupational hand dermatitis from hair preparations. 22 patients showed positive reactions to hair preparations and/or to their ingredients, and the other 10 patients showed negative reactions.The causative materials in the former cases, namely in allergic contact dermatitis were as follow; hair dyes in 15 cases, hair grooming preparations in 6 cases, cold permanent wave solutions in 4 cases, rubber gloves in 1 case, and shampoo in 1 case.In the patients with hair dye dermatitis, 2NPPD produced positive reactions in 40% of the patients tested.

A general consumer kicking patch test was also conducted. The results for 2NPPD are as follows: out of 51 patients tested , 24 patients showed positive results i.e 59% positive rate.

From the results we can conclude that 2 NPPD produces sensitizing reactions to human skin. In the supporting study (Danish (Q)SAR Database)

skin sensitisation potential of 2-nitro-p-phenylenediamine was tested in humans and guinea pig. Skin sensetization effects were estimated bythree different models i.e, Battery, CASE Ultra andleadscope used within Danish QSAR database for chemical 2-nitro-p-phenylenediamine.

Based on estimation skin sensetization effect were known when test chemical2-nitro-p-phenylenediamine exposed toGuinea Pig and Human.

On the basis of available information for the target , the test substance can be considered as sensitising to the skin, in accordance with the CLP criteria.

Migrated from Short description of key information:
The substance was found to be sensitising in human by patch test method.

Justification for selection of skin sensitisation endpoint:
In the supporting study (Contact Dermatitis. 1992 Feb; 26(2):101-7.)skin sensitisation potential of 2-nitro-p-phenylenediamine was tested in humans. A multicenter study was performed in 9 Italian centers by members of the GIRDCA' to evaluate the frequency and source of contact sensitization in a group of 302 hairdressers with dermatitis.Occupational habits and use of preventive measures were specifically investigated both in these 302 hairdressers. The results showed the presence of an occupationally relevant sensitization in 60.9% of the 302 hairdressers
 Positive reactions to 2 NPPD occurred in 24 reactions (7.9%) 2NPPD appears to be a sensitizer compared to other hair dyes tested

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The test substance 2 Nitro p phenylenediamine can be consideed as skinsensitizer 1 ,accordance with CLP criteria.