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EC number: 253-575-7
CAS number: 37640-57-6
Based on key study results, the oral LD50 of melamine cyanurate in rats
is >2000 mg/kg bw (Bromine Compound Ltd, 2000) and the inhalation LC50
(4 hours) in rats is >5.1 mg/L (BASF SE, 2016).
In view of the overall information, the dermal LD50 in rats is
considered to be >2000 mg/kg bw.
Table 1: Body weight (all means of 3 animals)
Group / Sex
Mean body weights ± standard deviation (g) at indicated time period
Group 1 / Males
251 ± 9
320 ± 17
362 ± 31
Group 2 / Females
185 ± 6
224 ± 15
239 ± 12
Exposure conditions: Supply air: 1.5 ± 0.0
m³/h, exhaust air: 0.6 ± 0.0 m³/h,
Test substance preparation: 62.8 g/h,
temperature: 22.8 ± 0.3 °C, relative humidity: 22.2 ±
Analytical concentration: 5.075 ± 0.622
mg/L (nominal concentration: 52.3 mg/L)
Particle size analysis: MMAD (µm) / GSD: 3.5
/ 2.6 (sample 1), 3.3 / 2.1 (sample 2)
In a GLP-compliant acute inhalation
toxicity study according to OECD 403 (single 4 -hour exposure, nose
only; limit test), male and female Wistar rats were exposed to the test
item melamincyanurat as a dust (key study, BASF 13I0834/09I058).
Mortality, clinical signs and body weights were recorded during the 14
day observation period. At necropsy, a macroscopical examination was
conducted. The actual measured test item concentration was 5.057 mg/L.
Particle size distributions were well within the respirable range, with
mass median aerodynamic diameters (MMADs) of 3.5 and 3.3 μm and
geometrical standard deviations of 2.6 and 2.1. There was no mortality.
Clinical signs of toxicity comprised of laboured respiration noted
during exposure (Hour 2 to Hour 4) and substance contaminated fur (Day
0). No clinical signs were observed from study Day 1 onwards. Mean body
weights decreased on the first post exposure observation days but
increased thereafter. No gross pathological abnormalities were detected.
The 4 -hour LC50 value was deemed as > 5.1 mg/L (calculated based on
analytical concentraton) under the conditions of this study.
Reliable data is available regarding acute
oral toxicity in rats (Bromine Compounds Ltd 2000a). The study was
performed following OECD testing guideline 423 and GLP. The acute oral
toxicity in mice (Wendtland 1980) deviates in reporting details and
investigated parameters from the OECD testing guidelines. For example,
the post-observation period was only 7 days and gross pathology was not
performed. As the tested dose of 12000 mg/kg bw is very high, this study
contributes to the hazard assessment. Both studies were performed with
gavage application. In rats, no mortality was observed in male and
female animals at a single dose of 2000 mg/kg bw. In mice, a single dose
of 12000 mg/kg bw caused mortality of 4/10 female and 1/10 male animals
during an observation period of 7 days. Acute oral LD50 values of
3461±155 and 4140±438 mg/kg bw were reported in publications in russian
language (Aleksandryan 1984a and Babayan 1985), no experimental details
were given and therefore it is not
possible to evaluate that information.
A reliable acute inhalation toxicity study in
rats (BASF SE, 2016), demonstrated a low toxicity of melamine cyanurate
via the inhalation route. The LC50 for a 4 hour exposure to a respirable
dust aerosol of melamine cyanurate was determined to be >5.1 mg/L
(males, females, sexes combined).
The acute oral toxicity data was published
together with acute intraperitoneal, dermal and inhalation data as well
as a 4-month inhalation study with (Babayan 1985 and 1986, Aleksandryan
1984 and 1986) The information on design and results is spread over the
publications and it is so limited that no validity assessment is
possible. However, the set of publications describe details on toxic
effects on kidneys including changes in blood urea nitrogen content and
plasma creatinine levels that are consistent with reliable data on
repeated dose toxicty.
For the supplementary acute inhalation
study, rats were presumably exposed to dust at concentrations of 170,
241, 594 and 2238 mg/m3 air. Only 241 and 2238 mg/m3 are mentioned in
the 1984 publication; the later publication (Aleksandryan 1986) also
mentions 170 and 594 mg/m3 air. It seems as if the whole animal was
exposed because the size of the chamber is given. For some parameters,
it is difficult to determine whether they belong to the investigation
with rats or with mice. The concentration of 241 mg/m3 air is reported
as being the threshold concentration for the increase in urea and
nitrogen in blood of rats.
For mice, the same publications report
an LC50 after 2h exposure of 1237 mg/m3 air.
For acute dermal toxicity, the LD50 is
reported as 5525 ± 158 mg/kg bw for rats without further information
such as duration of exposure or observation period (Babayan 1985).
During the skin sensitization study (Bromine
Compound Ltd. 2000d), guinea pigs were treated with
intradermal injection of ca 20 mg/kg bw plus an epicutaneous dose of ca
200 mg/kg bw applied in olive oil for 24h. No clinical signs of toxicity
and no mortality was observed during the 14 -day induction phase.
The acute intraperitoneal LD50 was
reported as 2020 ± 437 mg/kg bw for rats and 1125 ± 207 mg/kg bw for
mice (Babayan 1985).
Considering the results of the reliable key acute inhalation toxicity
study, the acute toxicity of melamine cyanurate via the inhalation route
is above the limit concentration of 5 mg/L.
Considering the overall information, the acute dermal toxicity of
melamine cyanurate in rats is considered to be above the limit dose of
2000 mg/kg bw.
Dangerous Substance Directive (67/548/EEC)
The available studies are considered reliable and
suitable for classification purposes under 67/548/EEC. As a result the
substance is not considered to be classified for acute oral, inhalation
and dermal toxicity under Directive 67/548/EEC, as amended for the 28th
time in Directive 2001/59/EC.
Classification, Labelling, and Packaging
Regulation (EC) No. 1272/2008
The available experimental test data are reliable and
suitable for classification purposes under Regulation 1272/2008. As a
result the substance is not considered to be classified for acute oral,
inhalation and dermal toxicity under Regulation (EC) No. 1272/2008.
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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