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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 220-864-4 | CAS number: 2921-88-2
- 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
![](https://echa.europa.eu./o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_toxicological-information.png)
Endocrine disrupter mammalian screening – in vivo (level 3)
Administrative data
- Endpoint:
- endocrine disrupter mammalian screening – in vivo
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 011
- Report date:
- 2011
Materials and methods
Test guidelineopen allclose all
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 440 (Uterotrophic Bioassay in Rodents: A Short-term Screening Test for Oestrogenic Properties)
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- other: US EPA Guideline No. 890.1600
- Deviations:
- no
- GLP compliance:
- yes
- Limit test:
- no
Test material
- Reference substance name:
- Chlorpyrifos
- EC Number:
- 220-864-4
- EC Name:
- Chlorpyrifos
- Cas Number:
- 2921-88-2
- Molecular formula:
- C9H11Cl3NO3PS
- IUPAC Name:
- O,O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate
- Test material form:
- solid
Constituent 1
- Specific details on test material used for the study:
- Chlorpyrifos Technical (milled)
Lot# KC28161419, TSN101285
Purity: 99.8%
Test animals
- Species:
- rat
- Strain:
- other: Crl:CD(SD)
- Sex:
- female
- State:
- immature female
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Analytical verification of doses or concentrations:
- yes
- Duration of treatment / exposure:
- 3 days
- Frequency of treatment:
- once a day
Doses / concentrationsopen allclose all
- Dose / conc.:
- 0 mg/kg bw/day (nominal)
- Dose / conc.:
- 0.5 mg/kg bw/day (nominal)
- Dose / conc.:
- 1.5 mg/kg bw/day (nominal)
- Dose / conc.:
- 4 mg/kg bw/day (nominal)
- No. of animals per sex per dose:
- 6
- Control animals:
- yes, concurrent vehicle
- Positive control:
- 17α-ethynyl estradiol (EE)
Examinations
- Observations and examinations performed and frequency:
- Daily observations and body weight measurements were recoreed.
On TD 4 (PND 22), animals were examined for precocious vaginal opening, weighed, euthanized, and the uteri were excised and weighed
before and after blotting.
Results and discussion
- Endocrine disrupting potential:
- negative
- Maximum tolerated dose level exceeded:
- yes
Results of examinations
- Clinical signs:
- no effects observed
- Mortality:
- no mortality observed
- Body weight and weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- There were no significant differences in body weights at any dose level of chlorpyrifos. However, average body weight gains in 4 mg/kg bw/day chloropyrifos rats were decreased by 37.5% (TD 1- 2), 31.4% (TD 1-3), and 22.6% (TD 1- 4) compared with the vehicle control group. These results indicated that a maximum tolerated dose was achieved in this study. There were no significant treatment-related effects on body weight gains at dose ≤ 1.5 mg/kg bw/day chlorpyrifos. There were no significant differences in the body weights or body weight gains between the positive control group and the vehicle control group.
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Details on results:
- Precocious vaginal opening was not observed in any rats on the day of termination (PND 22) as noted in the study file.
Effect levels
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 4 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- female
- Basis for effect level:
- other: negative
Applicant's summary and conclusion
- Conclusions:
- Test substance was negative in the uterotrophic assay.
- Executive summary:
To provide information on the potential for estrogenicity following short term exposure to chlorpyrifos, groups of 6 immature female Crl:CD(SD) rats were administered chlorpyrifos by oral gavage at dose levels of 0 (vehicle control), 0.5, 1.5, or 4 mg/kg bw/day beginning on postnatal day (PND) 19. A positive control group of 6 rats was exposed to 17α-ethynyl estradiol (EE) daily by gavage at 10 μg/kg bw/day. Rats in all treatment groups were dosed once daily for three days. On test day (TD) 4 (PND 22), animals were examined for precocious vaginal opening, weighed, euthanized, and the uteri were excised and weighed before and after blotting.
There was no animal mortality or treatment-related clinical signs observed in this study. There were no treatment-related changes in body weight in any chlorpyrifos-dosed animals and no significant differences in body weight gains at chlorpyrifos doses less than or equal to 1.5 mg/kg bw/day. At 4 mg/kg bw/day, body weight gain was significantly lower than the vehicle control group during TD 1- 3. Body weight gains for the 4-day study period at 4 mg/kg bw/day were decreased by 22.6% compared to the vehicle control group. There were no treatment-related effects on uterine weights in any chlorpyrifos-treated group compared to weights of the vehicle group with the terminal body weight as a covariate. The positive control group had the expected uterine weight increases without any significant change in body weight or body weight gain. No animal in this study had precocious vaginal opening. Uterine weights of the vehicle-treated animals met the performance criteria outlined in the applicable test guidelines, indicating acceptable assay sensitivity.
Overall, under the conditions of this study, there was no indication of estrogenicity from chlorpyrifos at doses ≤ 4 mg/kg bw/day, the highest dose level tested in female immature rats.
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.
![ECHA](/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/echa_logo.png)