Trimethylenediamine

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

pre-GLP Trimethylenediamine is structurally very similar to ethylenediamine (difference: chain length / one CH2-group) or ethylenediammonium dichloride (doses of ammonium and chloride not toxicological relevant), respectively. Thus, the test result is justified for read across to assess the toxic potential to reproduction of trimethylenediamine.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Portage, Michigan.
- Age at study initiation: (P) 43 wks;
- Weight at study initiation: (P) Males: 112-141 g; Females: 85-111 g;
- Housing: Two or three males or three or five females were housed per cage prior to mating;
- Diet : ad libitum, Purina Certified Rodent Chow 5002.
- Water :ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 55
- Photoperiod (hrs dark / hrs light): 12 hr light cycle

Route of administration:

oral: feed

Details on exposure:

Fresh diet was prepared biweekly with the percentage of EDA*2HCl in the diet adjusted to maintain a constant dosage level in grams per kilogram
for each sex according to the average animal body weight gain and diet consumption. At monthly intervals two diet samples were analysed.

Details on mating procedure:

The F0 parents were mated afier having received dietary EDA * 2HCl for 100 days. Twenty-six females and 13 males (randomly selected from 25 males) were mated per treated group while 52 females and 26 males (randomly selected from 50 males) were mated for the control group. During mating, two females were placed in a cage with one male; at this time all rats received EDA * 2HCl at the concentration in the diet for the respective female groups. Fifteen days after cohabitation, mating was discontinued and the females were placed in individual shoebox cages fitted with wire rod metal tops.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

At monthly intervals two diet samples were analysed.

Duration of treatment / exposure:

for two generations

Frequency of treatment:

daily

Details on study schedule:

At each dose level 13 male and 26 female rats were mated in both F0 and F1 generation (control group: 26 male and 52 female rats each); continuous treatment starting 100 days prior to cohabitation of F0 rats until weaning of F2 rats.

Remarks:

Doses / Concentrations:
50 mg/kg bw/day
Basis:
actual ingested

Remarks:

Doses / Concentrations:
150 mg/kg bw/day
Basis:
actual ingested

Remarks:

Doses / Concentrations:
500 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

13 male and 26 female. Control group: 26 male and 52 female rats

Control animals:

yes, concurrent no treatment

Parental animals: Observations and examinations:

BODY WEIGHT: Yes, measured weekly
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Food consumption determined on each cage of animals every 2 week. Dosage adjusted to keep a constant dosage level.

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Body weight; food consumption; organ weights;

Dose descriptor:

NOAEL

Effect level:

22.6 mg/kg bw/day

Based on:

test mat.

Remarks:

recalculated to EDA

Sex:

male/female

Basis for effect level:

other: Body weight; food consumption; organ weights; (Reclaculated to EDA base)

Dose descriptor:

NOAEL

Effect level:

27.9 mg/kg bw/day

Based on:

test mat.

Remarks:

calculated from EDA to trimethylenediamine

Sex:

male/female

Basis for effect level:

other: Study result generated with EDA*2HCl as test material was recalculated to EDA base and then - for read across - calculated for trimethylenediamine.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

500 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Body weight; food consumption; organ weights; histopathology: Hepatocellular pleomorphism

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

225.9 mg/kg bw/day

Based on:

test mat.

Remarks:

recalculated to EDA

Sex:

male/female

Basis for effect level:

other: Body weight; food consumption; organ weights; histopathology: Hepatocellular pleomorphism; (Recalculated to EDA base)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

278.6 mg/kg bw/day

Based on:

test mat.

Remarks:

calculated from EDA to trimethylenediamine

Sex:

male/female

Basis for effect level:

other: Study result generated with EDA*2HCl as test material was recalculated to EDA base and then - for read across - calculated for trimethylenediamine.

Reproductive effects observed:

not specified

Significant reduction in parental body weight gain of female rats in the intermediate and high dose group of the F0 generation, in the high dose group of the F1 generation and of male rats in the high dose group of both F0 and F1 generations. No substance-related parental deaths in the F0 or F1 generation. Significant decrease of absolute liver weight in male rats of the high dose F1 generation.

No macroscopic or histopathologic findings except a significant higher incidence of hepatocellular pleomorphism in both sexes of the high dose group of the F1 generation (6/10 male, 10/10 female; control: 0/20 each) and a significant decreased prevalence of kidney tubular mineralization in female rats of the high dose group of the F1 generation (0/10 female; control: 10/20).

In conclusion there was no evidence of fertility impairment or embryotoxic effect at dose levels that show maternal or paternal toxicity.

REPRODUCTIVE INDICES
	Dosage (g/kg,lday)
	0.50	0.15	0.05	0
	F0 → F1
Fertility index (%)
Male	92	100	92	92
Female	81	77	73	77
Gestation index (%)	100	100	100	100
Gestation survival index (%)	99.0 ± 3.4	100.0 ± 0.0	97.2 ± 11.8	99.2 ± 5.2
0- to 4-Day survival index (%)	90.0 ± 30.0	100.0 ± 0.0	94.4 ± 23.6	93.2 ± 22.4
4- to 14-day survival indexb (%)	99.4 ± 2.5	100.0 ± 0.0	94.1 ± 24.3	100.0 ± 0.0
4- to 2I-day survival indexb (%)	99.4 ± 2.5	100.0 ± 0.0	94.1 ± 24.3	99.7 ± 2.0
Pups born alive/litter	6.8 ± 3.5	8.6 ± 2.8	6.2 ± 3.9	8.4 ± 3.0
Days from first mating to parturition	28.3 ± 3.8	29.6 ± 2.0	29.8 ± 3.0	28.1 ± 3.0
	F1 → F2
Fertility index (%)
Male	100	92	92	100
Female	92	88	73	88
Gestation index (%)	100	100	100	100
Gestation survival index (%)	98.6 ± 6.7	99.1 ± 3.1	99.4 ± 2.5	99.5 ± 2.0
0- to 4-Day survival index (%)	98.0 ± 4.1	99.3 ± 3.5	98.6 ± 3.3	98.5 ± 4.1
4- to 14-day survival index (%)	100.0 ± 0.0	98.7 ± 6.3	100.0 ± 0.0	99.6 ± 3.0
4- to 21-day survival index (%)	100.0 ± 0.0	98.3 ± 8.3	100.0 ± 0.0	99.6 ± 3.0
Pups born alive/litter	8.5 ± 3.0	8.8 ± 2.2	9.4 ± 2.8	10.0 ± 2.5
Days from first mating to parturition	28.5 ± 3.2	28.8 ± 3.3	27.3 ± 3.6	28.4 ± 3.8

Conclusion: There was no indication of reproductive toxicity in Fischer 344 rats, following exposure to dietary EDA for two generations. A read across approach is justified as trimethylenediamine is structurally very similar to ethylenediamine (difference: chain length / one CH2-group) or ethylenediammonium dichloride (applied doses of ammonium and chloride of no toxicological relevance), respectively. Thus, there is no evidence that trimethylenediamine has reproductive potential.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

278.6 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

No GLP, but a scientifically well documented study.

Additional information

In a two-generation study, male and female Fischer 344 rats were fed diets containing 0, 50, 150 or 500 mg/kg/day of ethylene diammonium dichloride (Yang et al., 1984). At each dose level 13 male and 26 female rats were mated in both F0 and F1 generation. In the high dose group effects noted were decreased body weight gain in both F0 and F1 generations, a higher incidence of hepatocellular pleomorphism in F1 generation, and decreased liver weights in male rats in F1 generation. In the intermediate dose group female rats of F0 generation showed a decreased body weight gain. No evidence of impaired fertility or embryotoxicity was seen at any dose level. NOAEL parental was 50 mg/kg bw/day and NOAEL F1 offspring was 500 mg/kg bw/day for the test item. After read across, these results are equivalent to NOAEL parental of 27.9 mg/kg bw/day and a NOAEL F1 offspring of 278.6 mg/kg bw/day with respect to trimethylenediamine.

Read across is justified to assess the toxic potential to reproduction of trimethylenediamine, as the substance is structurally very similar to ethylenediamine (difference: chain length / one CH2-group) or ethylenediammonium dichloride (doses of ammonium and chloride not toxicological relevant), respectively.

Short description of key information:
There was no evidence of reproductive toxicity at levels of 500 mg/kg/day in rats in a two generation study with ethylenediammonium dichloride. After read across, this result is equivalent to 278.6 mg/kg bw/day trimethylenediamine (NOAEL offspring F1).

Justification for selection of Effect on fertility via oral route:
A reliable read across study.

Effects on developmental toxicity

Description of key information

Although significant growth retardation was observed in fetuses from dams receiving 1000 mg/kg/day ethylenediammonium dichloride, levels which resulted in maternal toxicity, there was no evidence of a teratogenic effect. Thus, triethylenediamine is also assumed not to be teratogenic. 

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

139.3 mg/kg bw/day

Quality of whole database:

No GLP, but a scientifically well documented studies.

Additional information

In a teratology study, female Fischer 344 rats (20/group) were fed 0, 50, 250 or 1000 mg/kg/day of ethylenediammonium dichloride (EDA-2HCl) in the diet on days 6-15 of gestation (DePass et al., 1987). Two control groups were used and standard endpoints for teratogenicity were evaluated. Maternal effects, such as decreased weight gain and feed consumption, were noted in the intermediate and high dose groups. Based on the study results, a maternal NOAEL of 26.9 mg/kg bw/day and a maternal LOAEL of 139.6 mg/kg bw/day were calculated for triethylenediamine after read across. In the high dose group there was an increased number of resorptions/litter, decreased mean fetal weight and length, higher incidence of shortened mandible, edematous eye bulge, shortened or missing sternebrae, delayed ossification and missing, or shortened innominate arteries. Based on the study results, for fetotoxicity, a NOAEL of 139.3 mg/kg bw/day and a LOAEL of 557.2 mg/kg bw/day were calculated for triethylenediamine after read across.

Trimethylenediamine is structurally very similar to ethylenediamine (difference: chain length / one CH2-group) or ethylenediammonium dichloride (doses of ammonium and chloride not toxicological relevant), respectively. Thus, the test result is justified for read across to assess the teratogenic potential / developmental toxicity of trimethylenediamine.

An oral gavage study (DePass et al, 1987) was conducted at 1000 mg/kg/day ethylenediammonium dichloride (applied on gestation days 6 through 15) in ten Fischer 344 rats to determine whether reduced body weight were directly due to ethylenediammonium dichloride (No fetal examinations were performed, since the study was only preliminary). Reduction of body weight gain and diet consumption, decreased number of live fetuses/litter and increased number of resorptions/litter was noted. A dose level for maternal toxicity of 557.2 mg/kg bw/day triethylenediamine was calculated based on the study results and read across.

In a conventional and pair feeding study (DePass et al, 1987), rats were administered a dietary dose of ethylenediamine dihydrochloride on gestation day 6- 15. A pair-fed control group received the same amount of feed as the dosed group. Male and female fetal weights and crown-rump lengths were significantly less than the negative control group and the pair-fed control group. In addition, the length of the innominate artery in male and female pups was shorter than for the pair-fed control and negative control groups. However, both the EDA-2HCl and the pair-fed control group had two fetuses from different litters with missing innominate artery. Missing innominate artery has been observed in the offspring of rats placed on diets deficient in folic acid (pteroylglutamic acid) and vitamin A. The authors concluded the shortened innominate artery from pups fed EDA-2HCl is not a teratologic effect since it would result in no functional deficit and may not be an irreversible change. It may be part of an overall growth retardation effect of EDA-2HCl along with reduced fetal weight. For triethylenediamine, a maternal LOAEL of 557.2 mg/kg bw/day and with respect to fetotoxicity a LOAEL also of 557.2 mg/kg bw/day were calculated based on the study results and read across.

In a further gavage study (Prince et al, 1993), New Zealand White rabbits were administered ethylenediamine dihydrochloride by gavage on gestation day 6-19. Doses were 0, 10, 40 or 80 mg/kg calculated as ethylene diamine. Number of resorptions, dead or alive fetuses, fetus weights and examination of live fetuses for external, skeletal or visceral effects was made. No characteristic clinical signs of toxicity were observed. No effect on maternal food intake, body weight or weight gain, liver or kidney weight. No adverse effects on prenatal viability, litter size, fetal weight or fetal morphology were observed. A maternal NOAEL and a developmental toxicity NOAEL of greater than 98.7 mg/kg bw/day triethylenediamine was calculated based on the study results and read across.

Conclusion based on the studies used for read across:

Although significant growth retardation was observed in fetuses from dams receiving 1000 mg/kg/day ethylenediammonium dichloride, levels which resulted in maternal toxicity, there was no evidence of a teratogenic effect. Thus, triethylenediamine is also assumed not to be teratogenic.

Trimethylenediamine as such was intraperitoneally administered (multiple doses of 66 mg/kg bw at days 8, 9, 10, 11, 12, 13 or 14 of gestation) to pregnant female mice during the time of maximal fetal ornithine decarboxylase activity at days 10-14 of gestation (Manen et al, 1983), resulting in an inhibition of fetal ornithine decarboxylase activity (measured 2 hours after treatment), and a proportional decrease in fetal weight (measured on day 18 of gestation). The treatment on gestation day 11, 13 or 14 resulted in statistically significant retardation of supraoccipital bone development and treatment on gestation day 12 caused significant increase in the incidence of malformed ribs (fused, forked, or kinked; 22 % vs. 0 %). There were no significant differences in total number of ribs. No significant incidences of gross or visceral malformations were observed. The treatment was neither fetocidal nor maternally lethal.

This study was treated as disregarded study as the route of application (i.p.) is not relevant for risk assessment.

Justification for selection of Effect on developmental toxicity: via oral route:
3 key read across studies were used in order to get to a reliable conclusion regarding the developmental toxicity potential of trimethylenediamine.

Justification for classification or non-classification

There was no evidence of reproductive toxicity at levels of 278.6 mg/kg/day in rats in a two generation study.

Based on the available data, trimethylenediamine is not liable for classification and labelling for toxicity to reproduction according to Regulation (EC) No 1271/2008 (CLP) or Directive 67/548/EC (DSD) criteria.