Ethylene dimethacrylate

Endpoint summary

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well conducted study, carried out by Nippon Bioresearch Inc.Hashima Laboratory (Japan).

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

yes

Remarks:

, An old version of OECD 422 (not containing functional observation battery test) had been  conducted.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan
- Age at study initiation: 10 weeks
- Weight at study initiation: male 341~380 g; the female was 232~256 g.
- Housing: suspended, stainless steel cage; 5/cage until breeding, then divided into separate rearing cages.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 day quarantine; 7 day acclimation

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ~ 24 ℃
- Humidity (%): 40 to 70%
- Photoperiod (hrs dark / hrs light): 12 hour light / 12 hour dark

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: dissolved in water


VEHICLE
- Justification for use and choice of vehicle (if other than water): water
- Concentration in vehicle: 5 mL/kg

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Males, 49 days; Females, from 14 days before mating to day 3 of lactation

Frequency of treatment:

Once daily

Remarks:

Doses / Concentrations:
0 (vehicle), 30, 100, 300, 1000 mg/kg/day
Basis:

No. of animals per sex per dose:

12

Control animals:

yes

Details on study design:

Post-exposure period: Male, 50 days; Females, day 4 of lactation
- Dose selection rationale: based on range-finding
- Rationale for animal assignment (if not random): random

Positive control:

not applicable

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations checked : general condition and mortality; estrus and abnormal labor conditions in females

BODY WEIGHT: Yes
- Time schedule for examinations: twice per week in males; before mating, twice a week during the mating period, 0, 7 ,14 and 21 days duirng pregnancy, during the feeding period was measured 0 and 4 days in females

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): one week prior to mating, then twice a week; additionally, in females, days 2,9,16 and 21 of pregnancy, four days over the feeding period.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day after treatment
- Anaesthetic used for blood collection: Yes; sodium pentobarbital
- Animals fasted: No data
- How many animals: No data
- Parameters checked in table [No.1] were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day after treatment
- Animals fasted: No data
- How many animals: No data
- Parameters checked in table [No.2] were examined.

URINALYSIS: No


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

Terminal kill: Males, day 50; Females, day 4 of lactation
GROSS PATHOLOGY: Yes; Thymus, liver, kidney, testis and epididymis weight in males and ovary in females was measured after removal, adrenal gland, brain, heart and spleen and 10% neutral buffered formalin solution (However, testicular and epididymal fluid Buan) was fixed. Post-mortem examination of feamles who did not give birth to Day 25 of pregnancy. Number of corpora lutea and the number of implantation scars in females.

HISTOPATHOLOGY: Yes; Paraffin-embedded specimens were prepared. Control group and 1000 mg / kg group of heart, liver, spleen, thymus, kidney, testis and epididymis in males ovary in females, adrenal and brain for the Preparation HE staining of tissue was examined histologically. In males, 1000 mg / kg in the kidney was considered to indicate a difference in the number of abnormal animals in the test group compared with the control group; 30, 100 and 300 mg / kg group were similarly examined. In females, 1000 mg / kg differences in the brain was considered to indicate an abnormal number of animals in the test group than the control group and changes in adrenal cases and 30, 100, 300 mg / kg group were similarly examined.

Other examinations:

Fetal examinations
(1) number of preterm birth and sex, number of stillborn children, the presence of abnormalities observed and the number of newborn.
(2) general condition and mortality
(3) measurement of body weight
(4) autopsy

Statistics:

Newborn screening as a unit has an average of one litter.
Weight (the parent animals, babies), food consumption, number of estrus, days mating, pregnancy [Day delivery (feeding 0) - date confirmed mating, the number of implantation scars, the number of birth control mobilize (number of babies stillborn baby + ), the number of newborn, number of children born dead, birth rate [(number of birth control mobilize / number of implantation scars) × 100], rate of production of child [(number of infant feeding 0 days / number of implantation scars) × 100], corpus number, implantation rates [(number of implantation scars / number of corpora lutea) × 100], fertility [(number of infant feeding 0 day / mobilize all of birth control) × 100], feeding baby number four day, feeding 4 day survival rate [(number of infant feeding 4 days / 0 Number of infant feeding day) × 100], unusual occurrence rate [(number of children with abnormal/ number of newborns) × 100], sex ratio (male / female), organ weights ( including the relative weight), results of blood tests, blood biochemistry test results for the mean and standard deviation were calculated for each group.
Significant difference test, Bartlett's test and the homoscedasticity of Law, analysis of variance, Dunnett method. Kruskal-Wallis test.
Copulation rate [(number of established animal mating / number of live animals) × 100], fertility [(number of female fertility / Establishment of animal mating) × 100], the birth rate [(number of female newborns / number of female fertility) × 100] is, χ ^ 2 using the test.
Cochran • Armitage was carried out using a test of dose-response trend test.

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

Detail:[Males]
1) General condition: With the survival animals, no death and no moribund  were found for 30, 100 and 300 mg/kg/day groups. At 1000 mg/kg/day, one  death on day 20 of dosing was seen and abnormality wasn't seen except for  salivation until the previous day.  With the dead animals, no abnormality  was found for 30, 100 and 300 mg/kg/day groups.  At 1000 mg/kg/day,  salivation was seen in about 1 to 30-minutes after dosing from day 3. 2) Body weight: No significant difference from control group was seen in  30, 100, and 300 mg/kg/day groups. At 1000 mg/kg/day, the significant low  value was recorded during day 18 to day 25 of dosing andduring day 32 to  day 50 of dosing.
3) Food consumption: At 30 and 300 mg/kg/day, no significant difference  from control was seen. At 100 mg/kg/day, the significant high values were  seen on day 31. but no dose-related changes were obserbed.At 1000  mg/kg/day, the statistically significant low values were recorded on day  13, 31 and during day 38 to day 45. 
4) Hematological examination: No significant difference from control  group was seen for all groups up to 1000 mg/kg/day dose.
5) Blood chemical examination: At 30 and 300 mg/kg/day,the significant  high value in BUN were seen. As the difference was very small, this was  not considered as the adverse effect of HEMA dosing.  At 100 mg/kg/day, a  higher value of BUN but not statistically signifficant difference from  control was recorded. At 1000 mg/kg/day, the significant high values were  recorded in BUN, K, Cl,I-phosphorous and Triglyceride. 
6) Autopsy: No abnormalitywas found for 30 and 100 mg/kg groups. In the  300 mg/kg group, the albedo spot in the kidney of the unilateral in the 1  animal and, the atrophy of the testiculus of the bilaterality and  softening were observed in the 1 animal. In the 1000 mg/kg group, the  dark-red of the thymus gland in the 1 animal and the hypertrophy of the  kidney of bilaterality in the 1 animal were observed. 
7) Weight oforgans: At 30 mg/kg/day, no significant difference from  control group in absolute and relative weight was seen for all organs. At  100 and 300 mg/kg/day, the significant high value was recorded in the  absolute weight of kidneys. At 1000 mg/kg/day, the statistically  significant high values were recorded in the relative weight of liver and  kidneys.
8) Histopathological examination: At 1000 mg/kg/day in the survival  animals, the dilatation of renal tubule in 3 animals in the kidney and  the dilatation of collecting tubules in 2 animals were obserbed. But, all  these changes were just slight. And the dilatation of renal tubule has a  significant difference but no dose-related changes.  As for the  dilatation of collecting tubules, it has no significant difference but  increase tendency. In the other group, there were hemorrhage of thymus  gland, microgranuloma of the heart, microgranuloma of the liver and  hepatocyte vacuolar degeneration of the centrilobular, renal basophilic  tubules, eosinophilic corpuscle in proximal tubule, cyst, diffusive  mineral deposition and neutrophilic infiltration. But it was judged with  the incidental change, because they were whether it equivalently seems  even in the control group or small number animals. And no abnormality was  observed in spleen, adrenal, testiculus and brain in the control and 1000  mg/kg group. In animal of death of the 1000 mg/kg group, there were  hemorrhage of the thymus gland, edema of the lung, autolysis of adrenal  and lung and thymus gland with the deadanimal of 1000 mg/kg group. As for  those degrees, all were just slight. In the adrenal with the abnormality  in the autopsy, no change which suggested hypertrophy was seen.   
[Females]
1) General condition: With the existence animales, no death and no  moribund were seen for 30, 100 and 300 mg/kg/day groups. At 1000  mg/kg/day, three death on day 6 of dosing, one death on day 12 of dosing  and one death on day 17 of dosing were seen. Salivation, decrease in  locomotor activity, adoption of a prone position, acrimation, soiled fur,  hypothermia, bradypnea were seen at 1000 mg/kg. With the death animals,  no abnormality was found for 30, 100 and300 mg/kg/day groups.  At 1000  mg/kg/day, salivation was seen in about 1 to 30-minutes after dosing from  day 3.
2) Body weight: Before mating period, no significant difference from control  group was seen at 30, 100 and 300 mg/kg/day. At 1000 mg/kg/day, the  significant lower values were recorded on day 4 and 5 of dosing. During  gestation period, no significant difference from control groups was seen  in 30, 300 and 1000 mg/kg/day groups. At 100 mg/kg/day, the significant  high values were recorded on day 21 of gestation,  but no dose-related  changes were observed. During lactation period, no significant difference  from control groups was seen in 300 and 1000 mg/kg/day groups. At 30 and  100 mg/kg/day, the significant high values were recorded on day 4 of  lactation, but no dose-related changes were obserbed.
3) Food consumption:  Before mating period, no significant difference from control group was  seen at 30, 100 and 300 mg/kg/day. At 1000 mg/kg/day, the significant low  value from control group was recorded on day 3, 6 and 13 of dosing. During  gestation period, no significant difference from control groups was seen  in 30 and 300 mg/kg/day groups. At 100 and 1000 mg/kg/day, the  significant high value from control group was recorded on day 16 of  gestation, but no dose-related changes were observed. During lactation  period, no significant difference from control groups was seen.
4) Weight of organs: At 30 mg/kg/day, no significant difference from  control group in absolute and relative weight was seen for all organs. At  100 mg/kg/day,the significant high value was recorded in the absolute  weight of kidneys. At 1000 mg/kg/day, the significant high values were  recorded in the relative and absolute weight of kidneys. 
5) Histopathological examination: Though at 1000 mg/kg/day survival  groups, neutrophilic infiltration (unilateral ) to medulla and papilla  mammae part in the kidney were observed in the 1 animal, the degree was  slight. Though extensive softening of the medulla oblongata in the brain  was observed in the 1 example at 1000 mg/kg group, the degree was slight.   In dead 6 animals of the 1000 mg/kg group, there were the edema in 1  animal in the lung, the atrophy in 1 animal in the thymus gland, the  atrophy in 5 animals and the atrophy of a Malpighian body in 1 animals in  the spleen, the hyperplasia of zona fasciculata in 3 animals and the  autolysis in 1 animal in the the adrenal and the erosion in 1 animal in  the small intestinal mucosa. The degrees of the atrophy in the thymus  gland and the atrophy of a Malpighian body were moderate, but the others  were slight.  All the changes are noted related agonism. No changes which  suggested, though the hypertrophy of the adrenal in 2 animals, dark-red  of the glandular stomach mucosa in 2 animals and dark-red of the  intestinum tenue were observed as abnormal in the autopsy of the 1000  mg/kg group.

Dose descriptor:

NOAEL

Effect level:

100 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

clinical biochemistry

organ weights and organ / body weight ratios

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Critical effects observed:

not specified

Conclusions:

An OECD 422 study was conducted with rats by gavage at doses of 0, 30, 100, 300 and 1000 mg/kg. The NOELs for repeat dose toxicity are considered to be less than 30 mg/kg for males, and 30 mg/kg for females.

Executive summary:

2-Hydroxyethyl methacrylate was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0, 30, 100, 300 and 1000 mg/kg/day. One male and 6 females of the 1000 mg/kg group (12 animals of each sex) died during the treatment period. In the males, BUN was elevated or tended to be high at 30 mg/kg or more, and the relative kidney weights were increased at 100 mg/kg or more. Salivation, suppression of body weight gain, decrease in food consumption, iucreased K, C1 and inorganic phosphorous, decreased triglyceride, increased relative liver weights, dilatation of renal tubules and collection tubules in the kidney were seen at 1000 mg/kg. In the females, the relative kidney weights were elevated or tended to be high at 100 mg/kg or more. Salivation, decrease in locomotor activity, adoption of a prone position, lacrimation, soiled fur, hypothermia, bradypnea, suppression in body weight gain, decrease in food consumption, increases of absolute and relative kidney weights, neutrophil cellular infiltration in the papilla and medulla and massive malacia in the medulla oblongata were seen at 1000 mg/kg. The NOELs for repeat dose toxicity are considered to be less than 30 mg/kg for males, and 30 mg/kg for females.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Although read-across has been used the database is regarded as being of high quality because relevant additional information from longer-term studies with metabolites and related chemicals is available which supports the assessment for EGDMA (read across done with a high level of confidence (see chapter toxicokinetics and category document, respectively)).

Additional information

For the evaluation of EGDMA the data of the primary metabolite HEMA are used. In the body, HEMA is the first metabolite resulting from the ester hydrolysis of EGDMA. HEMA was studied in an OECD422 combined repeat dose and reproductive/developmental toxicity screening test (Nihon Bioresearch, 1997). Groups of 12 male and 12 female rats were administered by gavage at dose levels of 0, 30, 100, 300, or 1000 mg/kg/day. Male rats were dosed for 49 days and female rats were dosed from 14 days prior to mating through Day 3 of lactation. In male rats slight effects were observed in kidneys at 300 mg/kg/d dose and above. The NOAEL for repeated dose toxicity was 100 mg/kg/d.

The supporting information from chronic toxicity studies with ethylene glycol and another, structurally closely related glycol dimethacrylate TREGDMA (triethyleneglycol dimethacrylate) provides two important pieces of information: The progression of EG-associated lesions over time does not exceed the additional safety factors applied to shorter term, in this case subacute, studies. Secondly, neither EG nor the methacrylate part of the molecule introduces additional toxicological alerts which are not covered by the key study used in this assessment.

EG (alcohol metabolite)

There are several rodent studies available with orally applied Ethylene glycol (EG). From those, subchronic and chronic feeding studies mainly performed by NTP were selected for this dataset for the reason of sufficient reliability and high relevance of the continuous uptake mode of a metabolite. In general, “the kidney is clearly identified as the most sensitive target organ in rats and mice after intermediate-duration oral exposure” of high doses > 1000 mg/kg/d”.Typical renal effects included oxalate crystal deposition and renal tubular dilation, vacuolation, and degeneration. Oxalate, a metabolite of glycolic acid, forms a precipitate in the presence of calcium, and the deposition of these crystals in the renal tubules are hallmarks of ethylene glycol toxicity. Glycolic acid accumulation and metabolic acidosis do not contribute to renal toxicity, which is solely caused by oxalate crystal accumulation. Males were more sensitive than females, and rats were more sensitive than mice” (ATSDR 2010).After subchronic feeding, the NOAEL in male mice was found to be 3230 mg/kg/d based on liver and kidney effects, while no adverse effects were found in female mice up to 16,000 mg/kg/d (NTP 1993). After subchronic feeding, the NOAEL in male rats was found to be 600-1000 mg/kg/d, while the NOAEL in female rats was found in female rats to be 1000-1500 mg/kg/d; both based on kidney effects (Melnick et al. 1984). After chronic feeding, the NOAEL in male mice was found to be 1500 mg/kg/d based on liver effects, while the NOAEL in female mice was found to be 3,000 mg/kg/d based on blood effects (all NTP 1993).

MAA (methacrylic metabolite)

Inhalation: In an OECD 413, 90-day vapour inhalation study in Sprague Dawley rats, MAA revealed general toxicity at 350 ppm (1253 mg/m3, the highest tested dose) in male animals (BASF, 2008). Local, marginal irritation of the respiratory epithelium in the nasal cavity was observed in two female animals. No changes in sexual organs or sperm mobility and sperm head counts were noted. The NOAEC was 100 ppm (352 mg/m3) for local irritation effects in male and females The NOAEC for systemic effects based upon reduced body weight gain in the presence of reduced feed intake but no other systemic effects was also 100 ppm (352 mg/m3) in male and females.

MMA (donor substance for MAA)

Oral: In an early 2-year chronic drinking water study with 25 male and 25 female rats administered with 6, 60 and 2000 ppm MMA no adverse effect were observed other than elevated kidney weights without corresponding histopathology in female rats at 2000 ppm (Borzelleca et al., 1964). The NOAEC was reported as 2000 ppm (124 and 164 mg/kg bw/d) in male and female rats.

Inhalation:

EU ESR on MMA (2002) concluded:“The combined chronic toxicity/carcinogenicity study of methyl methacrylate in F344 rats (Rohm and Haas, 1979a; the nasal tissues were reevaluated by Lomax, 1992; Lomax et al., 1997) was assessed for the requirements of the regulation 793/93/EEC as a valid study with restrictions. In comparison to the minimal requirements of a 28-day inhalation study (OECD 412), the list of organs to be weighted did not include the liver and the heart. 70 male and 70 female f 344 rats were exposed to vapor concentrations of 0, 25, 100 or 400 ppm methyl methacrylate for two years. Ten male and ten female rats from all groups were sacrificed after 13 and 52 weeks of exposure and all surviving rats were killed during week 104-106. Histological examination was conducted on more than 35 tissues including 3-4 cross-sections of the nasal cavity. Tissues from the trachea and the pharynx/larynx were not preserved for histopathologic examination. Mortality rates of treatment and control groups did not show significant differences. No compound-induced clinical signs were observed. After week 52, mean body weight of high dose females was generally lower than controls gaining intermittently significance. Reduced growth represented the only adverse effect outside the respiratory 'tract. Evaluation of hematology, clinical chemistry and urinalysis data did not reveal any methyl methacrylate associated effect.

At the end of the study, there were weight changes of some organs in mal es or females without any consistent relationship to the treatment. Similarly, no treatment-related macroscopic findings were observed in any of the dose groups. No histomorphological lesions other than nasal lesions were attributable to methyl methacrylate exposure of any exposed group. The examination of nasal cavities from male and female rats exposed to 400 ppm for 13 weeks or 52 weeks revealed a degeneration of the neuroepithelial olfactory cells lining the dorsal meatus of the anterior portions of the nasal cavities in conjunction with atrophy of Bowman's glands and focal basal cell hyperplasia. Chronic active inflammation, respiratory epithelial hyperplasia and squamous metaplasia characterized the lesions on the tips of the maxilloturbinate and nasoturbinats and focally along the nasal septum in more anterior regions of the nose. At the final sacrifice, nasal lesions were evident in mal es and females of the 100 ppm and 400 ppm exposure groups characterised by inflammatory degeneration of nasal epithelium. The primary target tissue was the olfactory epithelium with degeneration and/or atrophy of neurogenic epithelium and submucosal (Bowman's) glands lining the dorsal meatus, hyperplasia ofbasal cells, replacement of olfactory epithelium with ciliate (respiratory like) epithelium (metaplasia), and inflammation of the mucosa and/or submucosa. The severity of the lesions varied from minimal to slight at 0.4 mg/l (equivalent to 100 ppm) to moderate at 1.7 mg/l (equivalent to 400 ppm). At 0.1 mg/l (equivalent to 25 ppm) no pathological effects on the olfactory epithelium were reported, representing the NOAEC for local effects on the respiratory tract. Slight to moderate changes in respiratory epithelium occurred at 1.7 mg/l (equivalent to 400 ppm) and were characterized as hyperplasia of submucosal glands and/or goblet cells in the anterior regions of the nasal cativy. In the respiratory epithelium, there was inflammation of the mucosa and/or submucosa in males and females exposed to 400 ppm.... The NOAEC for systemic effects was considered to be 100 ppm for female rats and 400 ppm for male rats.

The cancer studies of the National Institutes of Health (NTP, 1986) revealed toxicological effects regarding the respiratory tract in male and female rats and mice. Groups of 50 male F344 rats and 50 B6C3Fl mice of each sex were exposed 6 hours per day, 5 days per week to air containing methyl methacrylate at target concentrations of 0, 2.1 or 4.2 mg/l (equivalent to 500 or 1,000 ppm) for 102 weeks. Groups of 50 female rats were exposed at concentrations of 0, 1.0 or 2.1 mg/l (equivalent to 250 or 500 ppm) on the same schedule. Increased incidences of serous and suppurative inflammation of the nasal cavity were observed in male and female rats.

Degeneration of the olfactory sensory epithelium characterized by loss of neuroepithelial cells was also observed in male and female rats. In exposed male and female mice inflammation of the nasal cavity, epithelial hyperplasia in the nasal mucosa and degenerative changes of the olfactory sensory epithelium were reported. In addition methyl methacrylate caused interstitial inflammation of the lung in high dose male mice. The trachea and larynx were also included in the histopathology, but no compound-related effects on these tissues were reported for rats and mice of each dose and sex. A NOAEC could not be established either from rats or mice.” This is true for local effects. For systemic effects, the NOAEC is is the highest tested dose, i.e. 1000 ppm for mice and male rats and 500 ppm for female rats.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
The NOAEL for EGDMA of 100 mg/kg is based on a subacute OECD 422 study with HEMA, the metabolite after the cleavage of the first ester bond of EGDMA. For EGDMA this is a conservative value for two reasons: First of all the NOAEL derived in the HEMA study is based on very slight effects in the kidney and BUN in the absence of histopathology, which is of questionable biological significance and the duration of the study was almost 50 days compared with the 28 d in a typical subacute study. Any NOAEL derived for EGDMA from this study is likely to be conservative.

Compliance to REACh requirements

The requirements are covered with an OECD 422 oral rat study with the primary metabolite HEMA, and subchronic/ chronic studies with the methacrylic metabolite MAA (90 d inhalation rat), its donor MMA (2 yr oral rat, 2 yr inhalation rat) or the alcohol metabolite EG (90 d feeding rat & mouse; 2 yr feeding mouse). All mentioned studies are reliable (Reliability 1 or 2) and the read across is done with a high level of confidence (see chapter toxicokinetics and category document, respectively).

Justification for classification or non-classification

No classification for systemic target organ toxicity. No specific target organ effects were observed in the relevant dose range.