N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine

Endpoint summary

Description of key information

Available in vivo animal data includes a negative Bühler, and a positive LLNA. However, the relevance of the results from the LLNA study can be questioned, as this study is shown to provide false-positive results with (irritating) surfactants. Recent MoA evaluation has show that the substance causes the migration of Langerhans cells, but that this is irritant pathway mediated rather than sensitising parthway mediated. Profiling of the chemical indicates no binding to protein.

So far also the use and handling of this material has not lead to reports of concern regarding possible sensitising properties.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From October 23,1995 to January 03, 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Justification for non-LLNA method:

The Buehler test was conducted before the requirement for LLNA testing came into force.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: D. Hall, Newchurch, Staffordshire, England.
- Age at study initiation: Approx. 6-7 weeks
- Weight at study initiation: 270 to 315 g
- Housing: In groups of five in suspended metal cages with wire mesh floors
- Diet: A vitamin C enriched guinea-pig diet FD2, ad libitum.
- Water (e.g. ad libitum): Hay was given weekly.
- Acclimation period: 6 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Approx. 21
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

a) for induction: 1% v/v (0.33% test substance) in distilled water
b) for challenge: 0.5% v/v (0.15% test substance) in distilled water

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

a) for induction: 1% v/v (0.33% test substance) in distilled water
b) for challenge: 0.5% v/v (0.15% test substance) in distilled water

No. of animals per dose:

20 per group

Details on study design:

RANGE FINDING TESTS: The topical irritancy of a range of dilutions of the test substance was investigated. Based on the results of this study, 1% v/v concentration was chosen for induction and 0.5% v/v concentration was chosen for challenge. The former concentration was the concentration that produced some irritation but did not give rise to adverse effects, while the latter was the maximum concentration not giving rise to irritating effects.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 h
- Test groups: 20 test animals
- Control group: 10 negative control animals
- Site: Left shoulder region, 20 x 20 mm
- Frequency of applications: Days 1, 8 and 15
- Duration: 2 weeks
- Concentrations: 1% v/v

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 2 weeks after final induction
- Exposure period: 6 h
- Test groups: 20 test animals
- Control group: 10 negative control animals
- Site: Right flank, 50 x 50 mm
- Concentrations: 0.5% v/v
- Evaluation (hr after challenge): 24 and 48 h after the removal of the patches

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.15%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Erythema, edema and dryness and sloughing of the epidermis

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.15%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Erythema, edema and dryness and sloughing of the epidermis.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.15%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Erythema, edema and dryness and sloughing of the epidermis

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.15%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Erythema, edema and dryness and sloughing of the epidermis.

Key result

Reading:

other: Both readings: 24 and 48 h

Hours after challenge:

48

Group:

negative control

Dose level:

0%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

Erythema, edema and dryness and sloughing of the epidermis

Remarks on result:

other: see Remark

Remarks:

Reading: other: Both readings: 24 and 48 h. . Hours after challenge: 48.0. Group: negative control. Dose level: 0%. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: Erythema, edema and dryness and sloughing of the epidermis.

Reading:

other: Overall result

Group:

positive control

Dose level:

25%

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

GHS criteria not met

Conclusions:

Under the study conditions, the test substance was not considered to be sensitising to the skin of guinea-pigs.

Reference 2

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

5 February 2002 - 11 March 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

(draft, Nov 2000)

Deviations:

yes

Remarks:

during the preliminary test, the vehicle used was a mixture acetone/olive oil in the proportion 1/4 (v/v) instead of 4/1 (v/v).

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

Species, strain and sex: CBA/J mouse, nulliparous and non-pregnant females
Age/weight: approximately 9 weeks old
Mean body weight ± standard deviation of 19.9 ± 1.2 g.
Number: 6 females for the preliminary test, 28 females for the main test.
Breeder: Janvier, Le Genest-Saint-Isle, France.
Acclimation: at least 5 days before the beginning of the study.
Allocation to groups: animals were assigned to the treatment groups by hand procedure.
Identification: individually by a number on the tail

The conditions in the animal room were set as follows:
⋅ temperature: 22 ± 2°C
⋅ relative humidity: 30 to 70%
⋅ light/dark cycle: 12 h/12 h
⋅ ventilation: approximately 12 cycles/hour of filtered, non-recycled air.
The temperature and relative humidity are under continuous control and recording.
The animals were housed individually in disposable crystal polystyrene cages (22.00 cm x 8.50 cm x 8.00 cm). Each cage contained autoclaved sawdust (SICSA, Alfortville, France). Sawdust is analysed by the supplier for composition and contaminant levels.

Positive control results:

In the positive control group given HCA at the concentration of 25%, a moderate increase in cellularity and a stimulation index exceeding the threshold value of 3 (SI = 9.07) was noted. The study was therefore considered valid.

Key result

Parameter:

SI

Value:

>= 1.29 - <= 9.07

No cutaneous reactions and no noteworthy increase in ear thickness were observed in the animals of the treated groups

Study results

Groups	1	2	3	4	5	6	7
Conc.% in AOO	0	0.01	0.025	0.05	0.1	0.25	HCA 25%
Viability %	92.73	93.33	97.20	88.24	95.59	94.81	84.09
amount of cells (x10^6 cells)	2.55	3.50	5.20	6.75	9.75	7.30	7.40
Cellularity index		1.37	2.04	2.65	3.82	2.86	2.9
Number of nodes	8	8	8	8	8	8	8
Disintegrations per min per group (dpm)	804.17	1040.87	1149.88	1060.55	1803.44	9203.35	7294.67
Stimulation Index (SI)		1.29	1.43	1.32	2.24	11.44	9.07
Increase earthickness	0.00	-0.96	1.98	1.00	2.94	1.94

Viability = 100 x viable cells / (viable cells + dead cells)

Cellularity index = amount of cells in the treated group/amount of cells in the vehicle group

Stimulation Index = dpm of treated group / dpm of control group

EC3 value = theoretical concentration resulting in a SI value of 3

Results of the preliminary test (ear thickness measurements)

During the preliminary test, slight to severe irritation, as shown by a 12 to 154.17% increase in the ear thickness, was noted at all tested concentrations. The highest concentration retained for the main test was therefore 0.25%.

Animal	Concen-tration %	Ear D1	Thickness D1	Erythema D2	Thickness D2	Erythema D2	%(*)
Female 71	50	RE	0.24	0	0.61	2/Su	154.2
Female 71	25	LE	0.26	0	0.49	1/Su	88.46
Female 72	50	RE	0.27	0	0.56	3/A/Su	107.4
Female 72	25	LE	0.28	0	0.53	2/Su	89.29
Female 73	10	RE	0.26	0	0.34	1	30.77
Female 73	5	LE	0.25	0	0.3	1	20
Female 74	10	RE	0.25	0	0.32	1	28
Female 74	5	LE	0.25	0	0.3	1	20

RE = Right ear

LE = Left ear

D = Day

A = Crusts

Su = Residual test item

0 = No erythema

1 = Very slight erythema (barely perceptible)

2 = Well-defined erythema

3 = Moderate to severe erythema

(*) = Percentage of ear thickness increase compared to day 1

			D1		D2		D3		D4		%(*)
Animal	Concen-tration %	Ear	Thickness	Ery-thema	Thickness	Ery-thema	Thick-ness	Ery-thema	Thick-ness	Ery-thema
Female 75	50	RE	0.25	0	0.26	0	0.30	0	0.38	0	52.00
Female 75	25	LE	0.25	0	0.25	0	0.25	0	0.28	0	12.00
Female 76	50	RE	0.26	0	0.25	0	0.30	0	0.37	0	42.31
Female 76	25	LE	0.25	0	0.25	0	0.26	0	0.29	0	16.00

RE = Right ear

LE = Left ear

D = Day

0 = No erythema

(*) = Percentage of ear thickness increase compared to day 1

Interpretation of results:

study cannot be used for classification

Conclusions:

Induces cell proliferation in auricular lymph nodes in mice after dermal application on the ear at highest non-irritating concentration under the conditions of this study.

Executive summary:

The substance was tested according to the draft OECD Guideline 429, in compliance with GLP, to assess possible induction of cell proliferation in auricular lymph nodes in mice after dermal application on the ear. Concentrations in preliminary assay were 50, 25, 10 and 5%. At these concentrations, a slight to severe increase in ear thickness was noted after a single application (+ 20% up to 130%), showing the severely irritant potential of the test item at these concentrations. At the concentrations of 1 and 0.5%, a slight to moderate increase in ear thickness was observed on day 4 (+14% up to 47%). The main test was performed at the following concentrations: 0.25, 0.1, 0.05, 0.025 and 0.01% using 4 animals per dose group, and included treatment with reference substance: alpha-hexyl cinnamaldehyde (HCA) 25%. No mortality and no clinical signs were observed during the study. No cutaneous reactions and no noteworthy increase in ear thickness were observed in the animals of the treated groups. A dose-related increase in the stimulation index was noted and the threshold positive value of 3 was exceeded at the maximum concentration of 0.25% (SI=11.44) only. In the absence of local irritation, the positive lymphoproliferative response observed at 0.25% was attributed to delayed contact hypersensitivity (Klein, 2002).

However, further evaluation of the LLNA study during the last couple of years, made it clear that this assay is not suitable for corrosive substances or surfactants. These are now known to induce false positive results. Dodecyldipropylenetriamine is a very corrosive surfactant, and therefore the results of this study should not be interpreted as indicative for possible skin sensitising potential.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The following information that is relevant for the assessment of possible sensitising properties is available onN-(3-Aminopropyl)-N-dodecylpropane-1,3-diamine (‘triamine substance’):

 

Buehler test

A study was conducted to determine the sensitizing potential of the triamine substance in a Buehler test according to EU Method B.6, in compliance with GLP. Twenty test and 10 control animals were used. The animals were first exposed to three topical induction doses (on Days 1, 8, and 15) of 0.5 mL of the 1% v/v test substance (0.3% a.i.) saturated in 20 x 20 mm patch of surgical gauze (3 layers thick). The patch was sealed to the skin under a 5 cm strip of “Blenderm” covered by elastic adhesive bandage (“Elastoplast”) wound around the trunk and sealed with “Sleek”. Contact was maintained for approximately 6 h for each induction exposure and the reactions were noted 24 h after dressing removal. Control animals were treated similarly to test animals with the exception of test substance omission from the induction applications. Two weeks after the final induction the control and test animals were exposed to challenge doses of 0.5 mL of the 0.5% v/v test substance (0.15% a.i.) test substance for 6 h under similar occlusive conditions followed by evaluation after 24 and 48 h. Dermal reactions were scored on a numerical system for oedema and erythema. Evaluations were performed blind. The animals were observed daily for clinical signs of toxicity and the bodyweights were recorded on Day 1 (first day of topical application) and on the last day of observations for the challenge. Localised dermal reactions were observed in 3/10 control animals at the 24 h observation and 1/10 control animals at the 48 h observation, consisting of varying dermal responses of erythema, oedema and dryness and sloughing of the epidermis. 5/20 test animals at the 24 h observation and 4/20 test animals at the 48 h observation exhibited very slight erythema with or without very slight oedema and dryness and sloughing of the epidermis. Two other test animals exhibited dryness and sloughing of the epidermis only, at the 48 h observation. Hence, it was concluded that none of the test animals showed a positive response. Under the study conditions, the test substance was not considered to be sensitising (Allan, 1996).

 

Local Lymph Node Assay (LLNA)

The triamine substance was tested according to the draft OECD Guideline 429, in compliance with GLP, to assess possible induction of cell proliferation in auricular lymph nodes in mice after dermal application on the ear. Concentrations in preliminary assay were 50, 25, 10 and 5%. At these concentrations, a slight to severe increase in ear thickness was noted after a single application (+ 20% up to 130%), showing the severely irritant potential of the test item at these concentrations. At the concentrations of 1 and 0.5%, a slight to moderate increase in ear thickness was observed on day 4 (+14% up to 47%). The main test was performed at the following concentrations: 0.25, 0.1, 0.05, 0.025 and 0.01% using 4 animals per dose group, and included treatment with reference substance: alpha-hexyl cinnamaldehyde (HCA) 25%. No mortality and no clinical signs were observed during the study. No cutaneous reactions and no noteworthy increase in ear thickness were observed in the animals of the treated groups. A dose-related increase in the stimulation index was noted and the threshold positive value of 3 was exceeded at the maximum concentration of 0.25% (SI=11.44) only. In the absence of local irritation, the positive lymphoproliferative response observed at 0.25% was attributed to delayed contact hypersensitivity (Klein, 2002).

 

In view of the likely false positive LLNA results from the LLNA conflicting with the profiling and QSAR information and results from in vivo guinea pig study, a more mechanistic study on the effects of N-(3-aminopropyl)-N-dodecylpropane-1,3-diaminein the skin was undertaken. This study explores the possible route of maturation of the Langerhans cells in the skin using a tissue-engineered full-thickness reconstructed human skin model with integrated Langerhans Cells (RhS-LC) (Kosten et al; Toxicology and Applied Pharmacology, 2015). The results clearly show that this substance is capable of inducing LC migration from the epidermis to the dermis of RhS-LC by irritant (CCL5) mediated rather than sensitizer (CXCL12) mediated.

 

Overall evaluation

Two studies were conducted to determine the skin sensitizing potential of the test substance, a Buehler test and an LLNA. The first study was negative whereas the second yielded a positive response. In order to conclude on these diverging results, the following points can be considered:

The test substance is a surfactant with corrosive properties. A number of papers published in peer reviewed journals (see references below) suggest that irritants and surfactants are more likely to give rise to false positive results in the LLNA, which is therefore not the most appropriate test system for these types of substances.

In general, the more complete a test system is, the more valid its results are for classification. The results of a screening assay may point to a possible hazard, but final evaluation in a full study always overrules screening results. The Buehler protocol involves a complete test system and therefore has a higher weight than an LLNA that lacks the crucial step of the hazard evaluation, i.e. evaluation of the presence of actual sensitisation (i.e. higher response compared to naive animals). Buehler study results could therefore be considered to overrule LLNA results.

Overall, considering its widespread use in concentrations above those that were tested in the LLNA study, the lack of reported sensitized individuals and the negative results from the Buehler test, the substance is not considered to be a human sensitizer.

 

Furthermore,

The MoA for skin reactions of N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine was evaluated by prof. Gibbs at VUMC University Medical Center. The results showed that indeed this substance caused the migration of Langerhans cells, but that this is irritant (CCL5) mediated rather than sensitizer (CXCL12) mediated.

 

Over the decades that this triamine substance is in use, there are no real convincing reports indicating sensitisation problems with this chemical. Also from production and handling in production sites as well from customers, there are no signs of sensitisation that have emerged so far.

 

Reports in public literature involving the observation of possible sensitization from this triamine substance are very rare. In these, the products involved are co-formulation of the triamine with other actives, specifically DDAC. The performed patch testing indicated that the reactions are probably more related to DDAC (showing reactions at lower concentrations) rather than the triamine (showing respectively no reaction, or low reaction, or a positive reaction at relative high concentration of 1%, whereas 0.3% was shown to be a threshold irritating concentration in guinea pigs.). (Dejobert Y, 1997)

 

 

References

·      Kreiling R, Hollnagel HM, Hareng L, Eigler D, Lee MS, Griem P, Dreessen B, Kleber M, Albrecht A, Garcia C, Wendel A. (2008).Comparison of the skin sensitizing potential of unsaturated compounds as assessed by the murine local lymph node assay (LLNA) and the guinea pig maximization test (GPMT). Food Chem. Toxicol. 46:1896-1904.

·      David Basketter, Nicholas Ball, Stuart Cagen, Juan-Carlos Carrillo, Hans Certa, Dorothea Eigler, Christine Garcia, Harald Esch, Cynthia Graham, Carl Haux, Reinhard Kreiling, Annette Mehling. (2009). Application of a weight of evidence approach to assessing discordant sensitisation datasets: Implications for REACH. Regul. Toxicol. Pharmacol. 55:90–96.

·      Garcia C, Ball N, Cagen S, Carrillo JC, Certa H, Eigler D, Esch H, Graham C, Haux C, Kreiling R, Mehling A. (2010). Comparative testing for the identification of skin-sensitizing potentials of nonionic sugar lipid surfactants. Regul. Toxicol. Pharmacol. 58(2):301-307.

·      Nicholas Ball, Stuart Cagen, Juan-Carlos Carrillo, Hans Certa, Dorothea Eigler, Roger Emter, Frank Faulhammer, Christine Garcia, Cynthia Graham, Carl Haux, Susanne N. Kolle, Reinhard Kreiling, Andreas Natsch, Annette Mehling. (2011). Evaluating the sensitization potential of surfactants: Integrating data from the local lymph node assay, guinea pig maximization test, and in vitro methods in a weight-of-evidence approach. Regul. Toxicol. Pharmacol. 60:389–400.

·      Kosten I J, Spiekstra SW, de Gruijl TD, Gibbs S (2015).MUTZ-3 derived Langerhans cells in human skin equivalents show differential migration and phenotypic plasticity after allergen or irritant exposure. Toxicology and Applied Pharmacology, Volume 287, Issue 1, 15 August 2015, Pages 35-42;https://doi.org/10.1016/j.taap.2015.05.017

·      Dejobert, Y, et al., (1997). Contact dermatitis from didecyldimethylammonium chloride and bis-(aminopropyl)-lauryl amine in a detergent-disinfectant used in hospital. Contact Dermatitis 37:(2) 95-96.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results of a Buehler test, the test substance does not warrant classification for skin sensitization according to CLP (EC 1272/2008) criteria.