Reaction mass of 4-tert-butylphenol and 1,3- phenylenedimethanamine and 2-({[3-(aminomethyl) benzyl]amino}methyl)-4-tert-butylphenol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction

Remarks:

other: 90 d repeated dose toxicity study

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Follows GLP and OECD 408

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3100 (90-Day Oral Toxicity in Rodents)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: F344/DUCrl

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (Kingston, New York)
- Age at study initiation: Approximately 7 weeks
- Housing: After assignment, animals were housed two per cage in stainless steel cages. Cages had solid floors with corncob bedding and shredded aspen for enrichment. Cages contained a feed crock and a pressure activated lixit valve-type watering system. The following environmental conditions were maintained in the animal room.
- Diet: Animals were provided LabDiet ad libitum.
- Water: ad libitum
- Acclimation period: Upon arrival, the animals were housed two to three per cage in stainless steel cages.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C with a range of 20°C-26°C
- Humidity (%): 50% with a range of 30-70%
- Air changes (per hr): 10-15 times/hour (average)
- Photoperiod (hrs dark / hrs light): 12-hour light/dark (on at 6:00 a.m. and off at 6:00 p.m.)

IN-LIFE DATES: From: November 5,2014 To: February 3 and 4,2015

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DOSE SOLUTION PREPARATION
All dosing solutions were prepared by mixing the test material in propylene glycol (PG) at concentrations of 1.67, 5, or 16.7 mg/ml, and administered at a dose volume of 6 ml/kg body weight to achieve the targeted dose levels.

VEHICLE
- Justification for use and choice of vehicle (if other than water): Mannich base PTBP-MXDA was determined to be soluble in PG at a concentration of 250 mg/ml
- Concentration in vehicle: 1.67, 5, or 16.7 mg/ml
- Lot/batch no. (if required): MKBS5987V.

Details on mating procedure:

animals were not mated

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

90 or 91 days

Frequency of treatment:

once daily seven days/week

Details on study schedule:

animals were not mated

Remarks:

Doses / Concentrations:
0, 10, 30, 100 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: A cage-side examination was conducted at least once a day, approximately at the same time each day (usually in the morning).


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical observations (DCO) were conducted on all animals pre-exposure and once per week throughout the study. The DCO was conducted on all animals, at approximately the same time each day according to an established format.

BODY WEIGHT: Yes
- Time schedule for examinations: All rats were weighed pre-exposure, twice during the first week, and weekly thereafter during the dosing period. Body weight gains were calculated relative to day 1.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OTHER: more details in section "repeated dose toxicity"

Oestrous cyclicity (parental animals):

not examined

Sperm parameters (parental animals):

not examined

Litter observations:

n.a.

Postmortem examinations (offspring):

n.a.

Reproductive indices:

n.a.

Offspring viability indices:

n.a.

Clinical signs:

no effects observed

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Other effects:

not examined

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

ORGAN WEIGHTS (PARENTAL ANIMALS)
Males given 100 mg/kg/day had higher mean relative testes and epididymides weights, that were statistically significant and interpreted to be reflective of the lower body weights of males at this dose level.
Females given 100 mg/kg/day had treatment-related statistically significant lower mean absolute and relative uterus weights, which corresponded to the histopathologic observation of very slight or slight diffuse atrophy of the uterus in 9/10 females at this dose level. Females given 100 mg/kg/day had lower absolute ovaries weights that were statistically significant and interpreted to be reflective of the lower body weights of females at this dose level.

GROSS PATHOLOGY (PARENTAL ANIMALS)
There were no treatment-related gross pathologic observations. All gross pathologic observations were considered to be spontaneous alterations, unassociated with oral gavage administration of Mannich base PTBP-MXDA.

HISTOPATHOLOGY (PARENTAL ANIMALS)
Nine females given 100 mg/kg/day had treatment-related very slight or slight diffuse atrophy of the cervix, uterus, and vagina. The atrophy of the uterus was characterized by diffuse decreased thickness of the endometrial mucosa, endometrial stroma, and tunica muscularis, and corresponded to the lower mean absolute and relative uterine weights at this dose level. The atrophy of the cervix and vagina was characterized by diffuse decreased thickness of the mucosa and fibromuscular wall of these tissues.

More details are given in section "repeated dose toxicity"

Dose descriptor:

NOAEL

Remarks:

fertility parameters

Effect level:

30 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: see 'Remark'

Clinical signs:

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Reproductive effects observed:

not specified

Conclusions:

In this 90 d repeated dose toxicity study the follwing effects on reproductive organs were noted:
Females given 100 mg/kg/day had treatment-related statistically significant lower mean absolute and relative uterus weights, which corresponded to the histopathologic observation of very slight or slight diffuse atrophy of the uterus in 9/10 females at this dose level. 9/10 females given 100 mg/kg/day had treatment-related very slight or slight diffuse atrophy of the cervix, uterus, and vagina.
The NOAEL for fertility parameters is 30 mg/kg bw/d.

Effect on fertility: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

30 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

 There is no specific dataset on reproductive toxicity for Mannich Base PTBP-MXDA, which does have a GLP guideline 90-d study and a GLP OECD 414 developmental toxicity study.

·        PTBP, a major component of Mannich Base PTBP-MXDA, comprises 46% of the MB PTBP-MXDA composition, and drives the current Repro Cat 2, H361f classification of this substance.

o   PTBP is classified as Repro Cat 2, H361f (Harmonized Classification).

o   Effects include atrophy of vaginal epithelium, very similar to the results from the 90-d study on MB PTBP-MXDA, which demonstrated uterine weight reduction and very slight to slight atrophy histopathologically. 

o   Mannich Base PTBP-MXDA had a NOAEL of 30 mg/kg bw/d for a 90-d study, including for the effect of uterine atrophy.

·        MXDA, a minor component of Mannich Base PTBP-MXDA comprising 28%, is not classified for reproductive toxicity.

·        The reaction product of Mannich Base PTBP-MXDA generally comprises <25% of the substance.

o   Although there are no direct data on reproductive toxicity of this reaction product, because the substance is already classified as Repro Cat 2, H361 due to the high levels of PTBP, and the lack of histopathological effects in the repeat dose 90-d study conducted in rats other than those that are similar to effects caused by high exposure to PTBP itself (vaginal epithelial atrophy) and therefore likely a result of the 46% PTBP in the substance, and given the lack of any specific developmental toxicity from Mannich Base PTBP-MXDA based on the OECD TG 414 Prenatal Toxicity test results, it seems very unlikely that Mannich Base PTBP-MXDA would have any specific reproductive or development toxicity separate from that related to the presence of PTBP.

 

 

Thus, in accordance with REACh Regulation Annex X, Section 8.7.3, column 2, no further testing is proposed to evaluate potential reproductive toxicity of Mannich Base PTBP-MXDA.

Short description of key information:
PTBP, a major component of Mannich Base PTBP-MXDA (46%), is classified as Repro 2 (H361f) (harmonized classification) based on atrophy of vaginal epithelium. Similar results were obtained from the 90 d repeated dose toxicity study on Mannich Base PTBP-MXDA, supporting the PTBP classification of Reprotox Cat 2 H361---classification also applied to Mannich Base PTBP-MXDA.

Effects on developmental toxicity

Description of key information

GLP guideline OECD 414 conducted in rats on Mannich Base PTBP-MXDA administered  via oral gavage: NOEL for embryonic/teratogenic effects = 100 mg/kg/day (maternal NOEL = 30 mg/kg/day).

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

GLP, Guideline study

Additional information

Groups of 24 time-mated female Crl:CD(SD) rats were administered Mannich Base PTBP-MXDA by gavage at dose levels of 0, 10, 30, or 100 mg/kg/day on gestation day (GD) 6-20. In-life parameters evaluated for all groups included clinical observations, body weight, body weight gain, and feed consumption. On GD 21, all surviving rats were euthanized and examined for gross pathologic alterations. Liver, kidneys, and gravid uterine weights were recorded, along with the number of corpora lutea, uterine implantations, resorptions, and live/dead fetuses. All fetuses were weighed, sexed, and examined for external alterations. Approximately one half of the fetuses were examined for visceral and craniofacial alterations while skeletal examinations were conducted on the remaining fetuses.

Administration of Mannich base PTBP-MXDA via gavage at 100 mg/kg/day produced treatment-related maternal toxicity evidenced by decreased body weight gain from GD 6-9 and increased relative liver weights. There were no treatment-related effects on clinical observations, body weight, or feed consumption, and no effect on gross pathologic alterations, kidney weights, gravid uterine weights, number of corpora lutea, uterine implantations, or resorptions. There was no indication of embryo/fetal toxicity or teratogenicity at any dose level tested.

Therefore, under the conditions of this study, the no-observed-effect level (NOEL) for maternal toxicity was 30 mg/kg/day, and the embryo/fetal NOEL was 100 mg/kg/day.

Justification for classification or non-classification

Based on the results of the OECD Guideline 414 study, there is no need to classify Mannich Base PTBP-MXDA for developmental toxicity.

Based on 46% PTBP in Mannich Base PTBP-MXDA composition, and the results from the 90 d repeated dose toxicity study, this substance is classified as Repro Cat 2, H361f (same as PTBP, harmonized classification).