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EC number: 200-002-3 | CAS number: 50-01-1
- 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
Link to relevant study record(s)
Description of key information
Based on data from acute toxicological studies and on physicochemical properties, high oral as well as inhalative absorption, but low dermal absorption can be expected for Guanidine hydrochloride.
Key value for chemical safety assessment
- Bioaccumulation potential:
- no bioaccumulation potential
- Absorption rate - oral (%):
- 100
- Absorption rate - dermal (%):
- 100
- Absorption rate - inhalation (%):
- 100
Additional information
No toxicokinetic studies are available for Guanidine hydrochloride. Assessment is based on available acute toxicity data and physicochemical properties and is developed with the aid of ECHA guidance on information requirements and chemical safety assessment chapter R7c.
Guanidine hydrochloride is soluble in water and has a log P value of <-1.7, therefore absorption has to be expected. After oral exposure signs of systemic toxicity including death were observed in acute toxicity studies, thus absorption of Guanidine hydrochloride has obviously occurred. As a consequence it is likely that the substance will also be absorbed if it is inhaled. This assumption is supported by data from an acute toxicity study by inhalation route, were systemic effects were observed. As data from a dermal acute toxicity study show no systemic effects at the limit dose of 2000 mg/kg bw/d, Guanidine hydrochloride is expected to be not favourable for dermal absorption.
As outlined in the Guidance on information requirements and chemical safety assessment, Chapter R.7c the stratum corneum provides its greatest barrier function against hydrophilic compounds. If water solubility is above 10,000 mg/L and the log P value below 0 the substance may be too hydrophilic to cross the lipid rich environment of the stratum corneum. Dermal uptake for Guanidine hydrochloride is considered to be low, due to the water solubility of 2150 g/L and the log P value of <-1.7. However, Guanidine hydrochloride is irritating and thus skin penetration may be enhanced. Therefore for safety assessment the dermal absorption is set to 100 %, which pose a worst -case.
This is supported by Ertell (2006) who summarised that “there is limited evidence that guanidine is not absorbed to any significant degree through the skin in animals“.
In the acute oral toxicity study clear toxic signs to the central nervous system/neuromuscular system were observed, which indicate that the substance has been distributed to the CNS. The excretion route is expected to be via the urine, because Guanidine hydrochloride dissociates in body fluids into the corresponding ions, is highly water soluble and has a low molecular weight of 95.53 g/mol.
Guanidine hydrochloride is also used as pharmaceutical. According to prescribing information guanidine is indicated for the reduction of symptoms of muscle weakness and easy fatigability associated with the myasthenic syndrome of Eaton-Lambert. The clinical pharmacology is described as follows: “Guanidine apparently acts by enhancing the release of acetylcholine following a nerve impulse. It also appears to slow the rates of depolarization and repolarization of muscle cell membranes.”
The effect of Guanidine hydrochloride on energy metabolism was studied in rat liver, muscle and kidney: Intraperitoneal injection of 2.2 mmol/kg bw/d Guanidinium hydrochloride for 7 d altered the carbohydrate metabolism in rat liver, muscle and kidney by stimulating the glycolytic pathway (Rao et al 1992).
The chloride ion is a naturally occurring essential ion in animals as well as humans with well-known metabolism and mechanisms of action as described in standard textbooks on pharmacology and physiology.
Reference
Ertell K.: A Review of Toxicity and Use and Handling Considerations for Guanidine, Guanidine Hydrochloride, and Urea. Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830
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