Registration Dossier

Administrative data

acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25 august - 11 september 2009
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Performed according to OECD / EC test guidelines and GLP compliant

Data source

Reference Type:
study report
Report Date:

Materials and methods

Test guidelineopen allclose all
according to
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
according to
EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)
according to
EPA OPPTS 870.1100 (Acute Oral Toxicity)
GLP compliance:
Test type:
acute toxic class method
Limit test:

Test material

Test material form:
Details on test material:
Identification Hexahydro-1,3,5-Trimethyl-S-Triazine
Molecular formula C6H15N3
Molecular weight 129.2
CAS Number 108-74-7
Description Clear pale yellow liquid
Batch FA9D0021
Purity 32.99%
Test substance storage At room temperature in the dark
Stability under storage conditions Stable
Expiry date 13 July 2011
Density 1.0202 at 16°C
pH 9.76 at concentration of @35%
The test substance is an aqueous solution containing 32.99% Hexahydro-1,3,5-Trimethyl-1,3,5-Triazine and three impurities at the following contents:
• Monomethylamine (CAS Number 74-89-5) : 0.1007% w/w
• Formaldehyde (CAS Number 50-00-0) : 0.300 % w/w
• Methanol (CAS Number 67-56-1) : 0.1655% w/w
The study was designed with water compensation (66.44%) and results were expressed as the neat Triazine. The test substance was not diluted with water due to potential for further hydrolysis to Formaldehyde.

Test animals

Details on test animals and environmental conditions:
SpeciesRat, Wistar strain Crl:WI (Han) (outbred, SPF-Quality). Recognized by international guidelines as the recommended test system (e.g. OECD, EC).Source: Charles River Deutschland, Sulzfeld, Germany.Number of animals9 Females (nulliparous and non-pregnant). Each dose group consisted of 3 animals.Age and body weightYoung adult animals (approx. 9 weeks old) were selected. Body weight variation did not exceed +/- 20% of the sex meanConditionsAnimals were housed in a controlled environment, in which optimal conditions were considered to be approximately 15 air changes per hour, a temperature of 21.0 ± 3.0ºC (actual range: 19.6 - 20.9ºC), a relative humidity of 40-70% (actual range: 42 - 76%) and 12 hours artificial fluorescent light and 12 hours darkness per day.Cleaning procedures in the room might have caused the temporary fluctuations above the optimal maximum level of 70% for relative humidity. Based on laboratory historical data, these fluctuations were considered not to have affected the study integrity.AccommodationGroup housing of 3 animals per cage in labeled Macrolon cages (MIV type; height 18 cm.) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom). Acclimatization period was at least 5 days before start of treatment under laboratory conditions.DietFree access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany). WaterFree access to tap water. Results of analysis for diet (nutrients and contaminants), sawdust, paper and water were assessed and did not reveal any findings that were considered to have affected the study integrity. All certificates and results of analysis are retained in the NOTOX archives.

Administration / exposure

Route of administration:
oral: gavage
unchanged (no vehicle)
Details on oral exposure:
The test substance was dosed undiluted as delivered by the sponsor. Adjustment was made for the density (1.0202) and the water content (66.44%) of the substance. Method: Oral gavage, using plastic feeding tubes.Fasting: Animals were deprived of food overnight prior to dosing and until 3-4 hours after administration of the test substance. Water was available.Frequency: Single dosage, on Day 1.
2000 mg Hexahydro-1,3,5-Trimethyl-S-Triazine /kg (10 mL/kg) body weight (or 6000 mg/kg not corrected for water content).300 mg Hexahydro-1,3,5-Trimethyl-S-Triazine /kg (10 mL/kg) body weight (or 894 mg/kg not corrected for water content).
No. of animals per sex per dose:
3 females at 2000 mg/kg6 females at 300 mg/kg
Control animals:
Details on study design:
The toxicity of the test substance was assessed by stepwise treatment of groups of 3 females. The first group was treated at a dose level of 300 mg/kg. The absence or presence of mortality of animals dosed at one step determined the next step, based on the test procedure defined in the guidelines, except that the second group was treated at 2000 and the third at 300 mg/kg. This was done for logistic reasons and did not affect the integrity of the study. The onset, duration and severity of the signs of toxicity were taken into account for determination of the time interval between the dose groups.

Results and discussion

Effect levels
Key result
Dose descriptor:
Effect level:
> 300 - < 2 000 mg/kg bw
Based on:
other: Hexahydro-1,3,5-trimethyl-1,3,5-triazine
Remarks on result:
other: NO 95 % CL as study was class method
All three females dosed at 2000 mg/kg and one (out of six) females dosed at 300 mg/kg were found dead on Days 1 or 2 post-treatment.
Clinical signs:
Hunched posture and/or piloerection were noted among the animals treated at 300 mg/kg between Days 1 and 10. Animals dosed at 2000 mg/kg showed a moribund condition and clonic spasms prior to death.
Body weight:
The mean body weight gain shown by the animals over the study period was considered to be normal.
Gross pathology:
Reddish discolouration of the glandular mucosa of the stomach was found in the animals that died during the study, at macroscopic post mortem examination. Macroscopic examination of the surviving animals at termination did not reveal any abnormalities.

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
The oral LD50 value of HEXAHYDRO-1,3,5-TRIMETHYL-S-TRIAZINE in Wistar rats was established to be within the range of 300-2000 mg/kg body weight.According to the OECD 423 test guideline, the LD50 cut-off value was considered to be 500 mg/kg body weight.