1,3-diphenylguanidine

Endpoint summary

Description of key information

One   study   was   available   (OCDE   Guideline   406,   and   GLP)   on   guinea   pigs   (DeJouffrey   1995).   No   cutaneous   reactions   attributable   to   the   sensitization   potential   of   DPG,   at   the   maximal   technically   utilizable   concentration   of   25%   were   observed   in   guinea-pigs.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

This old study on guinea pigs (1995) was available at the time of the Reach registration of this substance.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Centre d'Elevage Lebeau, 78950 Gambais, France
- Age at study initiation: no data
- Weight at study initiation: 356 +/-22g
- Housing: individually
- Diet (e.g. ad libitum): ad libitum (guinea-pigs sustenance reference 106 diet)
- Water (e.g. ad libitum): filtered tap water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/-2°C
- Humidity (%): 30 to 70%
- Air changes (per hr): about 12 cycles/hour filtered, non-recycled air.
- Photoperiod (hrs dark / hrs light): 12h/12h

Route:

intradermal and epicutaneous

Vehicle:

paraffin oil

Concentration / amount:

INTRADERMAL ROUTE (induction): concentration of 1% (w/w) in the vehicle.
CUTANEOUS ROUTE (induction and challenge): concentration of the test substance i.e. 25% (w/w) in the vehicle.

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Concentration / amount:

INTRADERMAL ROUTE (induction): concentration of 1% (w/w) in the vehicle.
CUTANEOUS ROUTE (induction and challenge): concentration of the test substance i.e. 25% (w/w) in the vehicle.

No. of animals per dose:

a control group = 5 females ; a treated group = 10 females

Details on study design:

On the day of each treatment, the test substance was ground using a motor and pestle then was prepared in the vehicle.

INTRADERMAL ROUTE :
On day 1, six intradermal injections were made into a clipped area (4 cm x 2 cm) in the scapular region, using a needle mounted on a 1 ml glass syringe. three injections of 0.1 ml were injected into each side of the animal as follow :
Control group : 1 = adjuvant ; 2 = vehicle; 3= adjuvant + vehicle.
Treated group : 1 = adjuvant ; 2 = vehicle et DPG ; 3= adjuvant + vehicle + DPG

CUTANEOUS ROUTE :
On day 7, the scapular area was clipped. As the test substance diluted is shown to be non-irritant after occlusive cutaneous treatment during preliminary test, the animals were treated with 0.5 ml of sodium laurylsulphate (10%) in vaseline to provoke local irritation. On day 8, a cutaneous application on the 6 injection areas (4 cm x 2 cm) of the scapular region was performed.
Control group : application of 0.5 ml of the vehicle
Treated group : application of 0.5 ml of a non-irritant concentration of the test substance i.e. 25% (w/w) in the vehicle.

CHALLENGE PHASE
At the end of the rest period on day 22, the test substance was applied at the Maximum Non-Irritant Concentration (MNIC), i.e. at a concentration of 25% (w/w) in the vehicle. On day 22, the animals from both groups received an application of 0.5 ml of the M.N.I.C. of the test substance on the posterior right flank, and 0.5 ml of the vehicle on the posterior left flank.

Challenge controls:

none

Positive control substance(s):

yes

Remarks:

DNCB

Positive control results:

The guinea pigs which used in recent studies showed a satisfactory sensitization response in 100% animals using a positive sensitizer.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.5 ml of a 25% solution

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

other: same results at the 2nd reading

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.5 ml of a 25% solution

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

None

Remarks on result:

other: same results at the 2nd reading

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.5 ml of a 25% solution

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

none

Remarks on result:

other: same results at the 2nd reading

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.5 ml of a 25% solution

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

none

Remarks on result:

other: same results at the 2nd reading

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.5 ml of a 0.5% solution

No. with + reactions:

5

Total no. in group:

5

Remarks on result:

other: same results at the 2nd reading

Reading:

1st reading

Hours after challenge:

48

Group:

positive control

Dose level:

0.5 ml of a 0.5% solution

No. with + reactions:

5

Total no. in group:

5

Remarks on result:

other: same results at the 2nd reading

Interpretation of results:

GHS criteria not met

Remarks:

not skin sensitizer

Conclusions:

According to the maximization method established by Magnusson and Kligman, no cutaneous reactions attributable to the sensitization potential of 1,3-DIPHENYLGUANIDINE (DPG), at the maximal technically utilizable concentration of 25% (w/) were observed in guinea-pigs.

Executive summary:

The potential of the 1,3-DIPHENYLGUANIDINE (DPG), to induce delayed contact hypersensitivity following intradermal injection and cutaneous application was evaluated in guinea-pigs according to the maximization method of Magnusson and Kligman. The study was conducted in compliance with the Principles of Good Laboratory Practice Regulations.

Fifteen guinea-pigs were allocated to two groups : a control group of 5 females, and a treated group of 10 females. The sensitization potential of DPG was evaluated after a 10 -day induction period during which time the animals were treated with paraffin oil (control group) or DPG (treated group). On day 1, in presence of frenud's complete adjuvant, 0.1 ml of the tst substance at a concentration of 1% (w/w) in the vehicle was administered by intraadermal route. On day 8, 0.5 ml of DPG at a concentration of 25% (w/w) in the vehicle was appplied by cutaneous route during 48 hours by means of an occlusive dressing. After a period of 12 days without treatment, a challenge cutaneous application of 0.5 ml of the vehicle (left flank) and 0.5 ml of DPG at a concentration of 25% (w/w) in the vehicle (right flank) were administered to all animals.

DPG and the vehicle were prepared on a dry gauze pad then were applied to the skin and held in place for 24 hours by means of an occlusive dressing. Cutaneous reactions on the challenge application sites were then evaluated 24 and 48 hours after removal of the dressing. After the final scoring period, the animals were killed. Due to the absence of cutaneous reactions, no skin samples were taken from the challenge application sites from all the animals.

No clinical signs and no deaths were noted during this study. After 24 and 48 hours following removal of the dressing of the cutaneous challenge application of the test substance, no cutaneous reactions were recorded. The guinea-pigs showed a satisfactory sensitization response in 100% animals using a positive sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Animal study

The potential of the DPG, to induce delayed contact hypersensitivity following intradermal injection and cutaneous application was evaluated in guinea-pigs according to the maximization method of Magnusson and Kligman (CIT 1995). The study was conducted in compliance with the Principles of Good Laboratory Practice Regulations.

Fifteen guinea-pigs were allocated to two groups : a control group of 5 females, and a treated group of 10 females. The sensitization potential of DPG was evaluated after a 10 -day induction period during which time the animals were treated with paraffin oil (control group) or DPG (treated group). On day 1, in presence of frenud's complete adjuvant, 0.1 ml of the test substance at a concentration of 1% (w/w) in the vehicle was administered by intra-dermal route. On day 8, 0.5 ml of DPG at a concentration of 25% (w/w) in the vehicle was applied by cutaneous route during 48 hours by means of an occlusive dressing. After a period of 12 days without treatment, a challenge cutaneous application of 0.5 ml of the vehicle (left flank) and 0.5 ml of DPG at a concentration of 25% (w/w) in the vehicle (right flank) were administered to all animals.

DPG and the vehicle were prepared on a dry gauze pad then were applied to the skin and held in place for 24 hours by means of an occlusive dressing. Cutaneous reactions on the challenge application sites were then evaluated 24 and 48 hours after removal of the dressing. After the final scoring period, the animals were killed. Due to the absence of cutaneous reactions, no skin samples were taken from the challenge application sites from all the animals.

No clinical signs and no deaths were noted during this study. After 24 and 48 hours following removal of the dressing of the cutaneous challenge application of the test substance, no cutaneous reactions were recorded. The guinea-pigs showed a satisfactory sensitization response in 100% animals using a positive sensitizer.

 

Human studies

Human cases have shown   that   contact   dermatitis   patients,   for   whom   a   rubber   intolerance   was   often   present,   occasionally   reacted   positively   to   DPG   in   the   patch   test.   Taken   into   account   the   negative   Guinea   pig   maximisation   assay,   it   can   be   infer   that   the   positive   reactions   observed   in   human   patients   with   contact   dermatitis   reflected   cross-reactions   rather   than   a   direct   sensitising   effect   of   1,3-diphenyl   guanidine. 

In   persons   suffering   from   a   contact   dermatitis   positive  DPG patch   tests   have   occasionally   been   described   (see   the   following   table).   The   following   main   contact   possibilities   were   named:   shoes   (Blank   &   Miller,   1952;   de   Vries,   1964;   Hjorth   &   Fregert,   1972;   Song   et   al.,   1979;   Lynde   et   al.,   1982;   Bajaj   et   al.,   1988),   articles   of   clothing   (Bandmann,   1956;   van   Dijk,   1968;   Song   et   al.,   1979),   rubberized   protective   clothing   (Fegeler,   1963;   Götz   &   Istvanovic,   1963;   Höfer   &   Hänemann,   1967;   Ross   &   Obst,   1969)   and   other   rubber   articles,   e.g. gloves or   the   rubber   parts   of   milking   machines   (Nater,   1975;   Song   et   al.,   1979). 

A   tire   production   employee,   whose   allergic   rhinitis   symptoms   occurred   only   at   the   workplace,   had   a   positive   patch   test   reaction   with   1%   1,3-diphenylguanidine   (Camarasa   &   Alomar,   1978). 

Garcia-Perez   et   al.(1984)   found   that   Spanish   agricultural   workers   with   a   contact   dermatitis   had   a   significantly   higher   sensitization   to   1,3-diphenylguanidine   than   a   contact   dermatitis   control   group   working   in   another   profession   (11.76%   versus   5.32%).   The   authors   attributed   this   to   possible   cross-reactions   with   pesticides,   as   some   of   these   substances   (e.g.   Cyprex)   are   guanidine   derivatives   and   others   (e.g.   the   cyanamides)   possess   a   similar   chemical   structure. 

The   available   data   are   summarised   in   the   following   table. 

 

Results   of   Patch   Tests   Performed   with   1,3-diphenylguanidine 

Subjects   (n)	Positive(n)	+ve   reaction   (%)	Concentration   (%)	Reference
35	2	6	1	Adams,   1972
524	6	0.01	1+2.1	Agrup,   1969
1	1	-	1	Aguirre   et   al.,   1994
229	18	8	0.5	Baer   et   al.,   1973
105	3	3	3	Bajaj   et   al.,   1988
5	1	20	1	Bandmann,   1956
24	0	0	1	Blank   &   Miller,   1952
74	2	3	n.   g.   *	Bonnevie   &   Marcussen,   1944
1	1	-	n.   g.	Bruze,   1994
1	1	-	1	Calan,   1978
686	13	2.3	n.   g.	Conde-Salazar   et   al.,   1993
5	0	0	0.25	Curtis,   1945
59	0		1	Dahl,   1975
9	1	11	n.   g	de   Vries,   1964
34	4	12	n.   g.	Garcia-Perez   et   al.,   1984
244	13	5	n.   g.	Garcia-Perez   et   al.,   1984
17	6	35	1	Götz   &   Istvanovic,   1963
1	1	-	n.   g.	Helander   &   Mäkelä,   1983
63	15	24	n.   g	Herrmann   &   Schulz,   1960
10	3	30	n.   g.	Höfer   &   Hönemann,   1967
316	14	4.4	1	Holness   and   Nethercott,   1997
20	7	35	n.   g.	Jung,   1977
5	1	20	1	Kanerva   et   al.,   1994
11	0	0	1	Kanerva   et   al.,   1996
31	2	7	1	Kantoh   et   al.,   1985
46	4	8.7	1	Kiec-Swierczynska,   1995
50	2	4	n.   g.	Kilpikari,   1982
15	0	0	1	Knudsen   et   al.,   1993
30	1	3.3	1	Koch   et   al.,   1996
1	0	-	1	Koch,   1996
61	2	3	1	Lisi   &   Simonetti,   1985
61	3	5	1	Lisi   &   Simonetti,   1985
119	3	3	1	Lynde   et   al.,   1982
1377	5	0.4	n.   g.	Meneghini   et   al.,   1963
49	2	4	70	Monsanto,   1982
6	2	33	1	Nater,   1975
n.   g.	n.   g.	3****	n.   g.	Orlov   et   al.,   1973
5	4	80	n.   g.	Piskin   et   al.,   2006
844	44	5	1	Rajan   &   Khoo,   1980
1600	25	1.6	1	Reifferscheid,   1979
2	0	-	n.   g.	Roed-Petersen   &   Menne,   1976
15	1	7	1+2	Ross   &   Obst,   1969
744	74***	9.9	1	Rudzki   &   Kleniewska,   1970
47	6	l3	n.   g.	Rudzki   &   Kohutnicki,   1971
1	1	-	n.   g.	Ruocco   &   Florio,   1986
50	6	12	1	Saha   et   al.;   1993
502	7	1.4	2	Suskind,   1984
4	3	75	n.   g	Takeda   et   al.,   1964
32	0	0	1	te   Lintum   &   Nater,   1973
1	0	-	1	Tuyp   &   Mitchell,   1983
3	1	33	2	van   Dijk,   1968
106	-**	-	1	Wilson,   1969

*   n.   g.   =   not   given 

**   no   evaluation   possible   due   to   a   number   of   irritating   reactions 

***   possible   irritating   reactions   could   not   be   ruled   out 

****   scarification   of   skin 

 

 

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the animal data, no classification for skin sensitisation is required for 1.3-diphenylguanidine.