Reaction mass of (2,4,6-trioxo-1,3,5-triazine-1,3,5(2H,4H,6H)-triyl)tri-2,1-ethanediyl triacrylate and 2-Propenoic acid, 1,1'-[[dihydro-5-(2-hydroxyethyl)-2,4,6-trioxo-1,3,5-triazine-1,3(2H,4H)-diyl]di-2,1-ethanediyl] ester

Repeated dose toxicity: dermal

Administrative data

Endpoint:

chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to GLP, following NTP standard protocol

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

not specified

Principles of method if other than guideline:

NA

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-ethyl-2-[[(1-oxoallyl)oxy]methyl]-1,3-propanediyl diacrylate

EC Number:

239-701-3

EC Name:

2-ethyl-2-[[(1-oxoallyl)oxy]methyl]-1,3-propanediyl diacrylate

Cas Number:

15625-89-5

Molecular formula:

C15H20O6

IUPAC Name:

2,2-bis(prop-2-enoyloxymethyl)butyl prop-2-enoate

Test material form:

solid - liquid: suspension

Details on test material:

- Name of test material (as cited in study report): trimethylolpropane triacrylate
- Physical state: slightly yellow, viscous liquid
- Analytical purity: > 78%
- Impurities (identity and concentrations): three of four impurities were tentatively identified as thylolpropane diacrylate, trimethylolpropane triacrylate-trimethylol-propane monoacrylate adduct, and trimethylolpropane triacrylate-trimethylol-propane diacrylate adduct
- Periodic reanalysis was performed at least every 6 months, no degeneration was detected
- Lot/batch No.: 08409HI (Aldrich Chemical Company, Milwaukee, WI)
- Stability under test conditions: stability was confirmed for up to 35 days at room temperature (sealed amber glass containers) and for up to 3h in simulated animal room conditions (not sealed)
- Storage condition of test material: room temperature protected from light in amber glass containers sealed with Teflon-lined lids.

Test animals

Species:

other: Mice and rats

Strain:

other:

Sex:

male/female

Administration / exposure

Type of coverage:

other: Dermal

Vehicle:

acetone

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dose formulations were analyzed approximately every 3 months. All formulations analyzed (35 for rats, 37 for mice) were within 10% of the target concentration. Samples taken from the animal room were generally high due to evaporation of acetone during dosing.

Duration of treatment / exposure:

104 to 105 weeks (rats); 105 to 106 weeks (mice) interim evaluations performed after 2, 13, 52 weeks

Frequency of treatment:

5 times per week

Doses / concentrations

Remarks:

Doses / Concentrations:
0.3, 1.0, 3.0mg/kg
Basis:

No. of animals per sex per dose:

65

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: In the 2-week and 3-month dermal toxicity studies (NTP, 2005), the skin was the only target organ identified for trimethylolpropane triacrylate. Therefore, the dose levels for the trimethylolpropane triacrylate 2-year studies were selected based on the severity of the skin lesions. Doses were selected to avoid significant skin irritation, and to preclude adverse effects on survival and growth of animals. Based upon the histologic data from the 3-month studies, 3 mg/kg was considered the likely maximum tolerated dose and an acceptable high dose for the 2-year toxicity and carcinogenicity studies. Thus, the doses selected for both rats and mice were 0, 0.3, 1.0, and 3.0 mg trimethylolpropane triacrylate /kg body weight in acetone.

Positive control:

None included in the study design

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: every 4 weeks

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: at 2, 13, and 52 weeks, skin from the site of application was collected from interim evaluation animals (5 per sex and dose), fixed in formalin, and examined microscopically.

BODY WEIGHT: Yes
- Time schedule for examinations: weekly for the first 13 weeks, every 4 weeks thereafter

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: No

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes. The following organs were fixed in 10% formalin, embedded in paraffin and stained with hematoxylin and eosin:
In addition to gross lesions and tissue masses, the following tissues were examined: adrenal gland, bone, brain, clitoral gland, esophagus, eyes, gallbladder (mice), Harderian gland, heart and aorta, large intestine (cecum, colon, rectum), small intestine (duodenum, jejunum, ileum), kidney, liver, lung and mainstem bronchi,lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin (site of application and control site), spleen, stomach (forestomach and glandular), testis with epididymis and seminal vesicle, thymus, thyroid gland, trachea, urinary bladder, and uterus.

Other examinations:

No

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

See below

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Details on results:

No differences in body weights or survival of dosed animals compared to the vehicle controls. There were no clinical findings of toxicity related to TMPTA administration.

TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis.

In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice.

Effect levels

Key result

Dose descriptor:

LOAEL

Effect level:

0.3 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

Local effects

Sex:

male/female

Basis for effect level:

other: The LOAEL was identified for female rats. (NOAEL of 0.3 mg/kg bw/d could be identified for male rats and male/female mice)

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The chronic toxicity of TMPTA dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. Local effects on skin was observed at 0.3 mg/kg/d in rats , whereas 0.3 mg/kg/d in mice was found as a NOAEL.

Executive summary:

The chronic toxicity of TMPTA dermally applied to mice and rats was examined in an NTP study (2012). Groups of 65 male and 65 female mice and rats received dermal applications of 0, 0.3, 1.0, or 3.0 mg TMPTA/kg body weight in acetone, 5 days per week for 105 to 106 weeks (core study). At 2 weeks, 13 weeks, and 12 months, five animals per sex per dose group were randomly selected for histological examination of skin tissue. Survival and mean body weights of all dosed groups were similar to those of the vehicle control groups. There were no clinical findings of toxicity related to TMPTA administration.

TMPTA increased the incidences of epidermal hyperplasia, characteristic of tumor promotion, at the site of application in a dose-dependent manner in rats and mice at all the time points examined. Dose dependent, significant increases in the incidences of hyperkeratosis at the site of application were observed in male and female rats. Both hyperplasia and hyperkeratosis are characteristics of chronic irritant contact dermatitis. These results are consistent with the dermal irritant effect of TMPTA reported. Skin irritation is an inflammatory response affecting all stages of carcinogenesis. In conclusion, dermal application of TMPTA for 2 years resulted in increased incidences of nonneoplastic lesions in the skin (site of application) of male and female rats and mice. No systemic toxicity was observed in rats and mice.

In conclusion, local effects on skin was observed at 0.3 mg/kg/d in rats (LOAEL) , whereas 0.3 mg/kg/d in mice was found as a NOAEL.