Sodium bis[4-hydroxy-3-[(2-hydroxy-1-naphthyl)azo]-N-(3-methoxypropyl)benzenesulphonamidato(2-)]cobaltate(1-)

Endpoint summary

Description of key information

The test item did not show sensitising properties in a LLNA in mice.

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:

key study

Study period:

2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Standard guideline study under GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Netherlands B.V. Postbus 6174 NL - 5960 AD Horst / The Netherlands
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 18,8 - 21,4 g
- Housing: individual
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum):ad libitum
- Acclimation period: yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 + 3°
- Humidity (%):
- Air changes (per hr): 30-86
- Photoperiod (hrs light): 6.00 a.m. - 6.00 p.m.

Vehicle:

methyl ethyl ketone

Concentration:

6.25, 12.5, and 25 % (w/v)

No. of animals per dose:

4

Details on study design:

In addition to the sensitising reactions the following observations and data were recorded during the test and observation period:
Mortality / Viability once daily (week day) from experimental start to necropsy.
Body weights prior to the first application and prior to treatment with 3HTdR.
Clinical signs (local / systemic) at 1 – 2 hours after each application. Especially the treatment sites were observed carefully.

Positive control substance(s):

not specified

Statistics:

The mean values and standard deviations were calculated in the body weight tables.
A statistical analysis was conducted for assessment of the dose-response relationship, and the EC3 value was calculated according to the equation
EC3 = (a-c) [(3-d)/(b-d)] + c
where EC3 is the estimated concentration of the test item required to produce a 3-fold increase in draining lymph node cell proliferative activity; (a, b) and (c, d) are respectively the co-ordinates of the two pair of data lying immediately above and below the S.I. value of 3 on the local lymph node assay dose response plot.

Parameter:

SI

Remarks on result:

other: see table below

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see table below

Test item Concentration	Group	DPM		Calculation		Result
			DPM-BG	Lymph nodes (LN)	DPM/LN	SI
	BG I	0	-	-	-	-
	BG II	9	-	-	-	-
	CG 1	4661,5	4657,0	8	582,1
6,25	TG 2	4412,5	4408,0	8	551,0	1,0
12,5	TG 3	4500,4	4495,9	8	562,0	1,0
25	TG 4	4978,6	4974,1	8	621,8	1,1

 

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item was found to be not a skin sensitiser in an in vivo Local Lymph Node Assay in mice under the described conditions.

Executive summary:

In the study the test item dissolved in methyl ethyl ketone was assessed for its possible contact allergenic potential.

For this purpose a local lymph node assay in female CBA-mice was performed using test item concentrations of 6.25, 12.5, and 25 %. The animals did not show any clinical signs during the course of the study and no cases of mortality were observed.

After the second application reddening of the ears could not be determined since the ear skin of the animals was dyed by the test item. In this study Stimulation Indices (S.I.) of 1.0, 1.0, and 1.1 were determined with the test item at concentrations of 6.25, 12.5, and 25 % (w/v) in methyl ethyl ketone, respectively.

The test item was not a skin sensitiser in this assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

No classification

No adverse effects were detected.