2,3-dihydroxypropyl methacrylate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1999

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

before 27th June 2018

Deviations:

no

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Methacrylic acid

EC Number:

201-204-4

EC Name:

Methacrylic acid

Cas Number:

79-41-4

Molecular formula:

C4H6O2

IUPAC Name:

methacrylic acid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

Nulliparous female Sprague-Dawley rats, weighing 180-200 grams, obtained from IFFA Credo Breeding Labs. Age at Start of Test: sexually mature females; age not specified. Mated females were  housed inclear polycarbonate cages with stainless steel wire lids and hardwood shavings for bedding. Food and water available ad libitum except  during exposures.
12 hours light-dark photocycle
Acclimatization of test animals: 2 weeks

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure (if applicable):

whole body

Vehicle:

unchanged (no vehicle)

Details on exposure:

Exposures were whole  body and conducted in a 200 L chamber. Chamber temperature was 23°C +/- 2 °C, and the relative humidity was 50% +/- 5%. Air was passed through a heated  bubbler containing test material. The vaporized material was then introduced into the exposure chambers.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentrations were determined 3 times at regular intervals during each 6 hr exposure by collecting
the material and analyzing against a standard using GC.
Target concentrations [ppm] Analytical concentrations [ppm]
mean +/- SD
--------------------------------------------------------------------------------
50 55.3 +/- 8.1
100 101.5 +/-16.9
200 207.3 +/- 24.7
300 316.0 +/- 36.7
--------------------------------------------------------------------------------

Details on mating procedure:

2-3 females were caged with one male rat for mating. The  onset of gestation was based upon the presence of sperm in the vaginal  smear and this was designated gestation day 0. After confirmation of  mating, females werere turned to an individual cage. 

Duration of treatment / exposure:

6 hours per day

Frequency of treatment:

day 6 to 20 of gestation

Duration of test:

Mated females were exposed 6 hr/day on days 6 through  20 of gestation.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

50 ppm

Remarks:

corresponds to 179 mg/m3

Doses / concentrations 2

Dose / conc.:

100 ppm

Remarks:

corresponds to 358 mg/m3

Doses / concentrations 3

Dose / conc.:

200 ppm

Remarks:

corresponds to 716 mg/m3

Doses / concentrations 4

Dose / conc.:

300 ppm

Remarks:

corresponds to 1076 mg/m3

No. of animals per sex per dose:

23 to 27 female rats were bred resulting in 22 to 23 pregnant rats used for experiment.

Control animals:

other: yes, concurrently exposed to filtered room air

Examinations

Maternal examinations:

BODY WEIGHT: Yes
- Time schedule for examinations: GDs 0, 6, 13 and 21
FOOD CONSUMPTION: Yes
- Time schedule for examinations: GDs 6-13 and 13-21

Ovaries and uterine content:

Uterine content was examined after termination: Yes
Examinations included:
- uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: No data
- Number of viable and dead foetuses: Yes
At necropsy, the uterine horns and ovaries were exposed to count the C.L., implantation sites, resorption sites, and viable and dead foetuses.
FERTILITY AND REPRODUCTIVE PERFORMANCE: The following data were recorded for each group of numbers of CL, and implantation sites o number of resorptions and viable and dead foetuses. O mean foetal body weights o foetuses examined for gross malformations and skeletal abnormalities of sex and of foetuses.

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes
- Skeletal examinations: Yes
- Head examinations: No data
Live foetuses were weighed, sexed, and examined for external anomalies. 50% of the live foetuses from each litter were preserved in Bouin's solution and examined for internal soft-tissue changes. The remaining foetuses (50%) were fixed in ethanol (70%), eviscerated and then processed for skeletal staining with alizarin red S.

Statistics:

The number of corpora lutea, implantation sites, and live foetuses, maternal food consumption and various body weights were analyzed by ANOVA, followed by Dunnett's test. The percentage of non-live implant, resorptions, and males and the proportion of foetuseswith alterations in each litter were evaluated by Kruskal-Walles test followed by Dixon-Massey test. Rates of pregnancy and percentage of litters with any malformations or external, visceral, or skeletal variations were analyzed using Fisher's test. Where appropriate, least squares analysis was performed. The level of significance was p < 0.05. The litter was used as the basis of analysis of foetal variables.

Indices:

Pre- and postimplantation loss; live birth index

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

no mortality observed

Description (incidence):

All animals survied the exposure.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Absolute weight gain was significantly reduced at 300 ppm.

Change in weight during gestation in Sprague-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation and euthanized on day 21:
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Concentrations No of dams Mean Body weight [g] +/- SD Mean body weight gain on GD [g] Mean absolute weight gain [g]
[ppm], 6 h/day on GD 6 6 - 13 13 - 21 6 - 21
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0 23 276 +/- 19 32 +/- 9 109 +/- 32 141 +/- 36 36 +/- 13
50 22 278 +/- 18 32 +/- 8 115 +/- 13 147 +/- 15 35 +/- 11
100 22 283 +/- 19 34 +/- 7 110 +/- 19 144 +/- 23 36 +/- 14
200 22 284 +/- 22 29 +/- 8 107 +/- 20 136 +/- 24 32 +/- 13
300 23 276 +/- 16 20 +/- 7** 91 +/- 26* 111 +/- 29** 12 +/- 14**
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
*, ** Denote significant differences from the control (0 ppm), p < 0.05 and p < 0.01, respectively.

Mean absolute weight gain: Mean body weight gain corrected by gravid uterine weight

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption was reduced at 300 ppm.
Food consumption of Sprague-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation and euthanized on day 21:
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Concentrations No of dams Mean food consumption [g/dam/day] on GD
[ppm], 6 h/day 6 - 13 13 - 21 6 - 21
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0 23 23 +/- 2 27 +/- 3 25 +/- 2
50 22 24 +/- 1 28 +/- 2 26 +/- 2
100 22 24 +/- 3 28 +/- 3 26 +/- 3
200 22 22 +/- 2 27 +/- 2 25 +/- 2
300 23 20 +/- 2** 24 +/- 2** 22 +/- 26*
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
*, ** Denote significant differences from the control (0 ppm), p < 0.05 and p < 0.01, respectively

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

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

not specified

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Maternal developmental toxicity

Number of abortions:

no effects observed

Description (incidence and severity):

There were no abortions reported.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

There were no significant changes in number of implantations across control and exposed groups.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

Total litter loss by resoprtion was not reported.

Early or late resorptions:

no effects observed

Description (incidence and severity):

The number of early and late resorptions was unaffected by treatment.

Dead fetuses:

no effects observed

Description (incidence and severity):

The number of dead foetuses was not reported.

Changes in pregnancy duration:

not specified

Description (incidence and severity):

In the OECD 414, a Caesarian section on GD 21 is performed.

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The number of pregnant females is comparable to the control.

Other effects:

not specified

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
All animals survived the exposure. Exposure to 300 ppm led to significant decreases in maternal weight gain and food consumption throughout exposure. Absolute weight gain was significantly reduced at 300 ppm.

Effect levels (maternal animals)

1

Key result

Dose descriptor:

NOAEC

Effect level:

200 ppm

Based on:

test mat.

Basis for effect level:

other: no adverse effects observed

Remarks on result:

other: corresponds to 716 mg/m³

2

Key result

Dose descriptor:

LOAEC

Effect level:

300 ppm

Based on:

test mat.

Basis for effect level:

body weight and weight gain

Remarks on result:

other: corresponds to 1076 mg/m3

Maternal abnormalities

Abnormalities:

no effects observed

Results (fetuses)

Fetal body weight changes:

no effects observed

Description (incidence and severity):

The foetal body weight was unaffected by treatment.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

Reproductive parameters in Sprague-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation and euthanized on day 21:
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Concentrations No of litters No. of live foetuses per litter
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0 22 14.73 +/- 3.92
50 22 14.86 +/- 1.93
100 22 14.05 +/- 3.17
200 22 13.77 +/- 3.99
300 22 14.05 +/- 3.76

Changes in sex ratio:

no effects observed

Description (incidence and severity):

Reproductive parameters in Sprague-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation and euthanized on day 21:
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Concentrations No of litters Average fetal body weight [g/per litter]
[ppm], 6 h/day All Males Females
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0 22 5.71 +/- 0.56 5.86 +/- 0.57 5.42 +/- 0.37
50 22 5.66 +/- 0.27 5.82 +/- 0.32 5.49 +/- 0.27
100 22 5.79 +/- 0.30 5.92 +/- 0.32 5.62 +/- 0.32
200 22 5.76 +/- 0.47 5.92 +/- 0.47 5.54 +/- 0.45
300 22 5.67 +/- 0.49 5.71 +/- 0.34 5.54 +/- 0.52
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Changes in litter size and weights:

not specified

Description (incidence and severity):

Litter size and weights were not reported.

Changes in postnatal survival:

not specified

Description (incidence and severity):

The pups were euthanised before birth.

External malformations:

no effects observed

Description (incidence and severity):

No significant increase of external foetal malformations was observed after exposure to methacrylic acid. There was no difference between the control and exposed groups.
Description please see attached document (Incidence of malformations and variations in fetuses of Spraque-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation).

Skeletal malformations:

no effects observed

Description (incidence and severity):

No significant increase of skeletal foetal malformations was observed after exposure to methacrylic acid. There was no difference between the control and exposed groups.
Description please see attached document (Incidence of malformations and variations in fetuses of Spraque-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation).

Visceral malformations:

no effects observed

Description (incidence and severity):

No significant increase of visceral foetal malformations was observed after exposure to methacrylic a cid. There was no difference between the control and exposed groups.
Description please see attached document (Incidence of malformations and variations in fetuses of Spraque-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation).

Other effects:

not specified

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There were no significant changes in number of implantations and live foetuses, in the incidence of non-live implants and resorptions, or in foetal weights across groups. One foetus of 200 ppm and two of the 300 ppm group showed different types of malformations. There was no consistent pattern of changes to suggest any treatment-related effects. The difference of foetuses with external, visceral, and skeletal variations did not differ between the control and the treated groups. No significant increase in embryo/foetal lethality or foetal malformations were observed after exposure to methacrylic acid. While maternal toxicity was observed, methacrylic acid caused no evidence of developmental toxicity up to 300 ppm.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEC

Effect level:

>= 300 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse effects observed

Remarks on result:

other: corresponds to 1076 mg/m³

Fetal abnormalities

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Any other information on results incl. tables

	Methacylic acid (Saillenfait 1999, OECD 414 rat inhalativ 6 h/day)
	control	50 ppm (corresponding 179 mg/m³)	100 ppm(corresponding 358 mg/m³)	200 ppm (corresponding 716 mg/m³)	300 ppm (corresponding 1076 mg/m³)
number of pregnant/ non pregnant dams	25 (total) / 23 (= 92%) pregnant / 2non pregnant	25 (total) / 22 (=88%) pregnant / 3 non pregnant	26 (total) / 23 (=84.6%) pregnant / 3 non pregnant	25 (total) / 22 (= 88%) pregnant / 3 non pregnant	26 (total) / 23 (= 88.5%) pregnant / 3 non pregnant
number of dams with abortions/ early deliveries/ stillbirths/ resorptions and/or dead fetuses	number of abortions not explicitly specified early deliveries were not reported (assumed to be 0) number of stillbirth were not reported (assumed to be 0) number of resorptions: 8.96 +/- 20.73	number of abortions not explicitly specified early deliveries were not reported (assumed to be 0) number of stillbirth were not reported (assumed to be 0) number of resorptions: 3.22 +/- 3.34	number of abortions not explicitly specified early deliveries were not reported (assumed to be 0) number of stillbirth were not reported (assumed to be 0) number of resorptions: 6.76 +/- 8.14	number of abortions not explicitly specified early deliveries were not reported (assumed to be 0) number of stillbirth were not reported (assumed to be 0) number of resorptions: 5.67+/- 12.77	number of abortions not explicitly specified early deliveries were not reported (assumed to be 0) number of stillbirth were not reported (assumed to be 0) number of resorptions: 10.61 +/- 21.45
Preimplantation loss (as no individual data is given in the publication, the preimplantation loss is calculated based on the means of number of corpora lutea and number of implantation sites)	12.55 mean	4.6 mean	7.58 mean	12.01 mean	9.81 mean
Postimplantation loss (as no individual data is given in the publication, the postimplantation loss is calculated based on the means of number of implantation sites and number of live offspring)	1.21 mean	3.26 mean	6.33 mean	4.11 mean	2.63 mean
Mean Body weight [g] on GD6	276 +/- 19 SD	278 +/- 18 SD	283 +/- 19 SD	284 +/- 22 SD	276 +/- 16 SD
Mean Body weight change [g]	141 +/- 36 on GD 6-21	147 +/- 15 on GD 6-21	144 +/- 23 on GD 6-21	136 +/- 24 on GD 6-21	111 +/- 29** on GD 6-21 significant different from the control (0 ppm)
mean gravid uterine weight including optionally body weight change corrected for gravid uterine weight (differenece between body weight gain from GD 6-21 and absolute body weight gain)	105 g mean	112 g mean	108 g mean	104 g mean	99 g mean
mean number and percent of live offspring	14.73 live pups/litter percentage not specified	14.86 live pups/litter percentage not specified	14.05 live pups/litter percentage not specified	13.77 live pups/litter percentage not specified	14.05 live pups/litter percentage not specified
mean foetal/ pup weight by sex and sexes combined	5.71 mean (g/litter) 5.86 males (g/litter) 5.42 females (g/litter)	5.66 mean (g/ litter) 5.82 males (g/litter) 5.49 females (g/litter)	5.79 mean (g/litter) 5.92 males (g/litter) 5.62 females (g/litter)	5.76 mean (g/litter) 5.92 males (g/litter) 5.54 females (g/litter)	5.67 mean (g/litter) 5.71 males (g/litter) 5.54 females (g/litter)
number and percent of foetuses and litters with malformations (including runts) and/ or variations	number of malformations:- litter affected: - number of variations: 37/324 or 11.4% litter affected: 21/22 (95.4%)	number of malformations:- litter affected: - number of variations: 35/327 or 10.7% litter affected: 20/22 (90.9%)	number of malformations:- litter affected: - number of variations: 41/309 or 13.3% litter affected:15/22 (68.2%)	number of malformations: 1/303 or litter affected: 1/22 or 4.5% number of variations: 29/303 or 9.6% litter affected: 16/22 (72.7%)	number of malformations: 2/309 or 0.6% litter affected: 2/22 or 9.0% number of variations: 39/309 or 12.6% litter affected: 16/22 (72.7%)
description and incidences of malformations and main variations (and/ or retardation	(detailed information see attached document to the IUCLID entry of this study (Incidence of Malformations and variations in fetuses of Spraque- Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation))	(detailed information see attached document to the IUCLID entry of this study (Incidence of Malformations and variations in fetuses of Spraque-Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation))	(detailed information see attached document to the IUCLID entry of this study (Incidence of Malformations and variations in fetuses of Spraque- Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation))	(detailed information see attached document to the IUCLID entry of this study (Incidence of malformations and variations in fetuses of Spraque- Dawley rats Inhaling Methacrylic acid on days 6 to 20 of gestation))	(detailed information see attached document to the IUCLID entry of this study (Incidence of malformationsand variations in fetuses of Spraque- Dawley rats inhaling Methacrylic acid on days 6 to 20 of gestation))

Applicant's summary and conclusion

Conclusions:

Using a valid scientific method, no significant increase in embryo/foetal lethality or foetal malformations were observed after exposure to methacrylic acid. While maternal toxicity was observed, methacrylic acid caused no  evidence of developmental toxicity up to 300 ppm.

Executive summary:

In an OECD 414 prenatal developmental toxicity study using whole body inhalation methacrylic acid at test concentrations of 50, 100, 200 and 300 ppm, corresponding to 179, 358, 716 and 1076 mg/m³ methacylic acid did not produce any embryo - or foetal lethality, nor foetal malformations, despite overt maternal toxicity (decreased body weight and feed consumption). The NOAEC (teratogenicity) was considerd to be 300 ppm (1076 mg/m³).