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EC number: 230-241-9
CAS number: 6976-93-8
Acute oral toxicity:Oral LD50 (rat, male/female) > 2000 mg/kg bw; OECD Guideline 401; GLP compliant, RL1Acute dermal toxicity:Dermal LD50 (rat, male/female) > 2000 mg/kg bw; OECD Guideline 402; GLP compliant, RL1; read-across from ETMA
an acute oral toxicity study according to OECD guideline 401 (adopted 24
February 1987), groups of fasted, 8 to 12 weeks old Sprague-Dawley CD
(Crl:CD BR) rats, 5/sex were given a single oral dose of MTMA (no
information on purity) 2000 mg/kg bw
and observed for 14 days.
animal died during the study. 3/5 males and 3/5 females showed no
clinical signs. Common signs of systemic toxicity noted in 2/5 males and
2/5 females were hunched posture, lethargy and piloerection with
additional signs of decreased respiratory rate 4 h to 2 d after dosing.
Animals had recovered 2 to 3 days after dosing.
animals showed the expected body weight gain during the study, except
for one female which showed a loss in bodyweight during the second week.
No abnormalities were noted at necropsy.
LD50 in males/females (rat) > 2000 mg/kg bw
experimental data on MTMA are available for the assessment of acute
dermal toxicity. However, a study is available for the source substance
is of similar low toxicity by the oral route so comparable dermal
toxicity would be expected.
A detailed justification for read-across is attached to IUCLID section
for the analogue approach
read-across hypothesis relies on the close structural similarity between
the source substance ETMA and the target substance MTMA, differing only
by one CH2-group. This read-across hypothesiscorresponds
to scenario 2 -different
compounds have qualitatively similar properties-
of the read-across assessment framework i.e.properties
of the target substance are predicted to be quantitatively equal to
those of the source substance. Namely, the structurally similar source
the toxicological properties of the target substance MTMA.
on the available data, including physicochemical data (water solubility
and log Kow) and acute oral toxicity, the read-across strategy is
supported by close structural analogy and similar toxicological profile
of the substances.
data are summarised in the data matrix; robust study summaries are
included in the Technical Dossier in the respective sections.
read-across from the existing toxicity studies conducted with the source
substance is considered as an appropriate adaptation to the standard
information requirements of the REACH Regulation for the target
substance, in accordance with the provisions of Annex XI, 1.5 of the
detailed justification for the proposed read-across approach is attached
to Iuclid section 13.
assessment elements for analogue approaches:
A.1 Characterisation of source and target substances
is close structural similarity between the source and the target
substances and the identity and characterisation of these substances is
unambiguous thereby giving a high level of confidence in the validity of
the read across.
target and source substances are highly pure mono-constituent
substances. They do not contain impurities, which would be of
target substance MTMA is an ester of Methacrylic acid and
2-Methoxyethanol. It is produced by esterification of Methacrylic acid
source substance ETMA is an ester of Methacrylic acid and
2-Ethoxyethanol. It is produced by esterification of Methacrylic acid
and 2-Ethoxyethanol. ETMA is different to MTMA in only one CH2-group.
A.2 Link of structural similarities and structural differences with the
target substance MTMA differs from the source substance ETMA by one CH2-group.
The physicochemical properties (water solubility and log Kow) are,
however, very similar. Thus, a comparable bioavailability by oral and
dermal route can be expected. Additionally, acute oral toxicity data are
available for MTMA and ETMA demonstrating low systemic acute toxicity,
which further support the read-across.
Target substance: MTMA
Source substance: ETMA
2-Propenoic acid, 2-methyl-, 2-methoxyethyl ester
2-Propenoic acid, 2-methyl-, 2-ethoxyethyl ester
1.3 at 23.3°C
(OECD Guideline 117/EU Method A.8; HPLC method)
1.8 at 23.3°C
31.33 g/L (pH 7.6) at 20°C
(OECD Guideline 105/EU Method A.6; flask method)
17.05 g/L (pH 5.3) at 20°C
A.3 Impact of impurities on the prediction
the target substance and the source substance, are highly pure
do not contain impurities, which would be of toxicological concern.
A.4 Consistency of properties in the data matrix
results of the acute oral toxicity studies demonstrate a low acute
toxicity for both the target and the source substance.
A.5 Reliability and adequacy of the source data
available studies have been conducted according to OECD guidelines and
have been assigned a reliability of 1 or 2 as documented in the data
matrix (see detailed justification for read-across attached to Iuclid
the study design of the respective source studies is adequate and
reliable for the purpose of this read-across.The results of the selected
key studies are adequate for classification and labelling and for risk
fully reliable study is available for acute oral toxicity of MTMA, so
read across is not employed.
an acute oral toxicity study according to OECD guideline 401 the oral
LD50 for MTMA in rats was > 2000 mg/kg bw.
of data on read-across chemicals:
source substances were of similarly low toxicity after single
an acute oral toxicity study according to OECD guideline 401 the LD50 of
ETMA (rat, male/female) was > 2000 mg/kg bw.
data from the metabolites 2-methoxyethanol and methacrylic acid are
included into the dossier to justify the read-across for repeated dose
toxicity and toxicity to reproduction.
Methacrylic acid had an LD50 of >2000 mg a.i./kg bw (25% dilution in
water or 10% dilution in corn oil). The LD50 of 2-methoxyethanol was
2460 mg/kg bw in rat. The comparable outcome of the acute toxicity
studies conducted with the target substance and the source substances
supports the read-across hypothesis.
study on acute inhalation toxicity is unjustified in accordance to REACH
regulation Annex VIII, column 2 due to exposure considerations as well
as in accordance to REACH regulation Annex XI due to scientific
considerations. The use of this substance will not result in aerosols,
particles or droplets of an inhalable size, so exposure to humans via
the inhalatory route will be unlikely to occur. Furthermore, systemic
toxicity relevant to humans did not appear in acute by oral or dermal
exposure. Considering the exposure probability and the available
information on the intrinsic toxic activity of the substance, an
inhalative systemic toxicity risk to humans is unlikely and therefore,
the conduct of an inhalative toxicity study is not scientifically
necessary. Thus, also animal welfare is respected according to REACH
an acute dermal toxicity study according to OECD guideline 402, adopted
24 February 1987, 5 male and 5 female app. 8 weeks old Sprague-Dawley
ICO: OFASD rats were dermally exposed to ETMA (99.94% a.i.) for 24 hours
under a semiocclusive dressing to approx. 10% of body surface area at a
single dose of 2000 mg/kg bw. Animals then were observed for 14 days.
females were found dead 24 h after treatment without any preclinical
clinical signs and cutaneous reactions were observed during the study.
days 1 and 5, a decrease in body weight was noted for 1/5 males, the
bodyweight gain was slightly reduced for 1/5 males and 2/5 females. The
body weight of these animals showed an improvement during the remainder
of the observation period. This finding was probably due to the stress
caused by the experimental conditions and was not attributed to
treatment with the test substance. The body weight gain of the surviving
animals was normal.
examination of the main organs of the animals found dead during the
study or sacrificed at the end of the study revealed no apparent
LD50 of ETMA (rat, male/female) > 2000 mg/kg bw.
are no data gaps in acute toxicity. Even though there is no information
on acute toxicity in humans, there is no reason to believe that the low
acute toxicity observed in experimental animals would not be relevant
for human health.
the available data, MTMA does not need to be classified for acute
toxicity according to regulation (EC) 1272/2008. Thus, no labelling is
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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