Registration Dossier
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: 200-543-5 | CAS number: 62-56-6
- 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

Short-term toxicity to fish
Administrative data
Link to relevant study record(s)
Description of key information
Five different studies were available in the assessment of the acute toxicity of thiourea towards fish. Species tested were Pimephales promelas, Leuciscus idus (L.), Hong Kong Guppy, Danio rerio and Oryzias latipes. In none of the studies a LC50 value could be obtained that would be close to the regulatory cut-off value of 100 mg/L for classification. Therefore, a classification of thiourea for acute toxicity to fish is not warranted.
Key value for chemical safety assessment
Additional information
Five different studies are available for the assessment of the acute fish toxicity of thiourea. Two of these studies were rated reliable with a reliability code of Klimisch I (TNO, 1988) and Klimisch II (Curtis & Ward, 1988), and were therefore used as key studies in the chemical safety assessment. The remaining studies were rated unreliable and are used as supporting information in the assessment. Some information was not further included in the assessment due to considerable doubt on the correctness of reported results (“disregarded studies”).
In a 96-h acute toxicity study, Curtis & Ward (1981) determined the toxicity of thiourea to the freshwater fish Pimephales promelas (fathead minnow) at five concentrations (spacing factor 0.6; maximum concentration: 600 mg/L; control: 0 mg/L) under static conditions. The 96-h LC0 was determined to be ≤ 600 mg/L as no mortality occurred at any of the concentrations tested.
In 1988, TNO conducted a acute toxicity study for thiourea with the freshwater fish species Leuciscus idus (L.) ("Goldorfe") according to DIN 38412 "Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung" (DEV-11. Lieferung 1982) L15. The total exposure duration was 48 h. After 48 h, no mortality or other signs of sublethal effects could be observed at 10,000 mg/L which was the highest concentration tested. The 48h LC50 value was found to be greater than 10,000 mg/L.
Although the test duration of 48 h used in this study conducted by TNO (1988) is shorter than the recommended standard test duration of 96 h, this information is used in the chemical safety assessment as the study is considered reliable and the highest concentration tested – at which at the same time no lethal or sublethal effects could be observed - is a factor of 100 higher than the regulatory cut-off value of 100 mg/L for classification.
The results from the two key studies (Curtis & Ward, 1981; TNO, 1988) clearly demonstrate that thiourea cannot be classified as toxic towards fish. This information is further supported by the following information:
In 1977, experiments on the acute toxicity of thiourea to fish were conducted at the SKW Trostberg laboratory using Hong Kong Guppy (guideline or method not reported; Klimisch III). At 6,000 mg/L Hong Kong Guppies showed 100% mortality after 14 h of exposure, no animals died at 5,000 mg/L, however the total exposure duration was not reported for this dose level.
In 1981, Danio rerio fish were exposed to thiourea in a study conducted by Korte & Greim under static through conditions for a 48-h. The 48-h LC50 was found to be 16,000mg/L, (LC50 = 16,000 mg/L, LC100 = 20,000 mg/L).
The following information is available for thiourea but is not further considered in the chemical safety assessment (disregarded studies”):
The BUA Stoffbericht 179 (1996) cites results on the acute toxicity (48 h) of thiourea for Oryzias latipes from "Japan Chemical Industry Ecology - Toxicology and Information Center. 1992. Biodegradation and Bioaccumulation Data of Existing Chemicals Based on the CSCL Japan". The 48-h LC50 toxicity of thiourea for Oryzias latipes is cited to be below 1000 mg/L. This result is considerably lower than the other reported LC50. This could be attributed to a specific species sensitivity of Oryzias latipes. However, there is doubt that this result is cited correctly in the BUA Stoffbericht 179, because also the result of Korte & Greim (1981) for the 48-h LC100 for Danio rerio was falsely cited as being below 20,000 mg/L. Unfortunately, the original reference for Oryzias latipes was not available for review.
In 1977, the SKW Trostberg laboratory also conducted experiments on the acute toxicity of thiourea to fish were conducted at using Leuciscus idus (guideline or method not reported; Klimisch III). 100 % mortality was found for Leuciscus idus after 8 h and 2 h exposure at 5,000 mg/L and 6,000 mg/L, respectively. No animals died at 4,000 mg/L (however, total exposure duration not reported for this dose level). This result for Leuciscus idus is in conflict with the results from the TNO study (1988) which was rated to be reliable (Klimisch I). Therefore, the result of SKW Trostberg (1977) is not further considered in the chemical safety assessment.
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.

Route: .live2