Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 202-905-8 | CAS number: 100-97-0
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Description of key information
The LD50 ofmethenamineis > 20000 mg/kgbwafter single oral administration to rats. The LD50 ofmethenamineafter dermal application in the rats is > 2000 mg/kgbw.
Key value for chemical safety assessment
Acute toxicity: via oral route
Link to relevant study records
- Endpoint:
- acute toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1966
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: old public available literature, non GLP, non Guideline
- Qualifier:
- no guideline available
- Principles of method if other than guideline:
- The study was conducted in 1966 before OECD Guidelines existed. Public available literature. No guideline indicated but similar to OECD limit test, but with two doses. For details on method see IUCLID5 materials and methods section.
- GLP compliance:
- no
- Test type:
- other: no data
- Limit test:
- no
- Species:
- rat
- Strain:
- Wistar
- Sex:
- not specified
- Details on test animals or test system and environmental conditions:
- adult rats were used.
- Route of administration:
- oral: gavage
- Vehicle:
- water
- Details on oral exposure:
- An 80% aqueous solution was administered by oral intubation.
- Doses:
- 10 g/kg and 20 g/kg
- No. of animals per sex per dose:
- five animals per group (sex not indicated)
- Control animals:
- not specified
- Details on study design:
- Two groups of five rats were given 10 g/kg and 20 g/kg of methenamine as an 80% aqueous solution by oral intubation.
- Statistics:
- not indicated.
- Preliminary study:
- no data on preliminary study
- Sex:
- not specified
- Dose descriptor:
- LD50
- Effect level:
- > 20 000 mg/kg bw
- Sex:
- not specified
- Dose descriptor:
- other: NOAEL
- Effect level:
- >= 20 000 mg/kg bw
- Mortality:
- no mortality observed.
- Clinical signs:
- other: not indicated
- Gross pathology:
- not indicated
- Other findings:
- not indicated
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- The LD50 of methenamine is > 20000 mg/kg bw after single oral administration to rats.
- Executive summary:
In an acute oral toxicity study, 2 groups of adult Wistar rats (5 animals per dose) were given a single oral dose of methenamine (80 %) in water at doses of 10000 and 20000mg/kg bw.
Oral LD50 > 20000 mg/kg bw
All animals survived.
Hexamethylenetetramine is of practically no toxicity based on the LD50 in rats.
Reference
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 20 000 mg/kg bw
- Quality of whole database:
- old public available literature, non GLP, non Guideline
Acute toxicity: via inhalation route
Endpoint conclusion
- Endpoint conclusion:
- no study available
Acute toxicity: via dermal route
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 2 000 mg/kg bw
- Quality of whole database:
- GLP study according to guidelines.
Additional information
Oral:
Key study:
In an acute oral toxicity study (Della Porta, 1966), 2 groups of adult Wistar rats (5 animals per dose) were given a single oral dose of methenamine (80 %) in water at doses of 10000 and 20000 mg/kg bw. The Oral LD50 was > 20000 mg/kg bw. All animals survived. Methenamine is of practically no toxicity based on the LD50 value noted in rats.
Supporting studies:
- In an acute oral toxicity study (Dreyfors, 1989), groups of rats were given a single oral dose of methenamine. The oral toxicity of methenamine is very low based on an LD50 of 9200 mg/kg bw in rats.
- In an acute oral toxicity study (Vujosevic, 1986), groups of C3H mice were given a single oral dose methenamine. Oral LD50 = 1853 mg/kg bw
The lower values reported by Vujosevic (1986) are not considered relevant, as the studies have too many limitations. This view is supported by the EU RAR. Methenamine is of low Toxicity based on the LD50 in mice.
Dermal:
Key study:
In an acute dermal toxicity study (Berthold, 1997), groups of young adult HsdCpb: WU rats (5/sex) were dermally exposed to methenamine (99.3 %) in water for 24 hours to the shaved shoulder region at a limit dose of 2000 mg/kg bw. Animals then were observed for 14 days.
Dermal LD50
Males > 2000 mg/kg bw
Females > 2000 mg/kg bw
Combined > 2000 mg/kg bw
No mortality occurred. The only clinical finding was a yellowish discoloured application site in all male and female rats. The finding started on day 1 after application and was still present at the end of the 14-day observation period. At necroscopy no alterations were detected.
Methenamine is not toxic, when applied to the skin of rats.
Inhalation:
No studies available.
In accordance with column 2 of REACH Annex VIII, the test acute toxicity after inhalation (required in section 8.5) does not need to be conducted as acute toxicity studies for oral and dermal application are available. Inhalation exposure is regarded negligible as no particles below 125 µm were detected in particle size analysis (see section 4.5).
Human Data:
Systemic toxicity was not observed.
Conclusion:
Limited data on the acute toxicity of methenamine in humans are available.
Acute toxicity in rats was demonstrated to be very low after oral and dermal application with LD50 values of > 20 g/kg bw and 2 g/kg bw, respectively. Data on inhalation toxicity of methenamine are not available, and not needed as exposure via inhalation (as gas or aerosol) is not likely to occur.
Justification for selection of acute toxicity – oral endpoint
Study with highest reliability
Justification for selection of acute toxicity – inhalation endpoint
In accordance with column 2 of REACH Annex VIII, the test acute
toxicity after inhalation (required in section 8.5) does not need to be
conducted as acute toxicity studies for oral and dermal application are
available. Inhalation exposure is regarded negligible as no particles
below 125 µm were detected in particle size analysis (see IUCLID5
section 4.5).
Justification for selection of acute toxicity – dermal endpoint
Only key study available.
Justification for classification or non-classification
Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is not considered to be classified 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.