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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 251-882-0 | CAS number: 34206-40-1
- 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
Developmental toxicity / teratogenicity
Administrative data
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Test method according to EPA OTS 798.4900. No data on GLP.
Data source
Reference
- Reference Type:
- publication
- Title:
- Unnamed
- Year:
- 2 003
Materials and methods
Test guidelineopen allclose all
- Qualifier:
- according to guideline
- Guideline:
- EPA OTS 798.4900 (Prenatal Developmental Toxicity Study)
- Version / remarks:
- (40 CFR 798.4900)
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 414 (Prenatal Developmental Toxicity Study)
- GLP compliance:
- not specified
- Limit test:
- no
Test material
- Reference substance name:
- Butanone oxime
- EC Number:
- 202-496-6
- EC Name:
- Butanone oxime
- Cas Number:
- 96-29-7
- Molecular formula:
- C4H9NO
- IUPAC Name:
- butan-2-one oxime
- Details on test material:
- - Name of test material (as cited in study report): Methyl ethyl ketoxime (MEKO)
- Source: Allied Signal, Inc. (Morristown, NJ, USA).
- Physical state: Liquid
Constituent 1
Test animals
- Species:
- rat
- Strain:
- other: Sprague-Dawley CR:CD BE VAF/Plus
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories, Inc., Kingston, NY, USA
- Age at study initiation: 90 days old
- Weight at study initiation: 222 - 291 g
- Housing: Individually in stainless steel cages
- Diet (e.g. ad libitum): Purina Certified Rodent Meal No. 5002
- Water (e.g. ad libitum): Fresh water, ad libitum
- Acclimation period: 13 days prior to mating
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 64-79 ºF
- Humidity (%): 64-70 %
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs ligth)
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- water
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS: Solutions were prepared fresh weekly in distilled water to provide dose levels as appropriate for use in either the dose range-finding studies or main studies.
VEHICLE
- Amount of vehicle (if gavage): Dose volumes were 10 mL/kg. - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Methyl ethyl ketoxime was analyzed for stability. Analysis of dosing solutions showed stability of the desired concentrations of methyl ethyl ketoxime for up to 14 days. Fresh dosing solutions were prepared weekly to adjust for body weight changes and administration of constant dose volumes. Analytical recoveries were within 6% of the respective nominal concentrations.
- Details on mating procedure:
- - Impregnation procedure: cohoused
- Proof of pregnancy: Evidence of mating was determined by the presence of a copulation (day 0 of day of gestation). - Duration of treatment / exposure:
- Gestation Days 6-15.
- Frequency of treatment:
- Daily.
- Duration of test:
- 20 days.
Doses / concentrations
- Remarks:
- Doses / Concentrations:
0, 60, 200 or 600 mg/kg bw/day
Basis:
actual ingested
- No. of animals per sex per dose:
- 25 females per dose
- Control animals:
- yes, concurrent vehicle
- Details on study design:
- - Dose selection rationale: A preliminary dose range finding study was performed. Groups of six rats (dams) were given MEKO doses by gavage of 0, 25, 100, 200, and 400 mg/kg on gestation days 6–15. Methemoglobin determinations and reticulocyte counts were performed on all surviving dams on gestation days 7, 12, 16, and 20. Parameters evaluated were the same as in the main test (see below). Furthermore, blood samples were obtained from the orbital plexus of dams. MEKO doses for the main studies were chosen after evaluation of the results of the preliminary studies and the same duration of treatment during gestation was applied (see results included on section "Any other information on results").
Examinations
- Maternal examinations:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations: mortality and morbidity and for signs of toxicity (including behavioral abnormalities).
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: During the treatment period, animals were observed between 1/2 and 2 h following dosing for sings of toxicity.
BODY WEIGHT: Yes
- Time schedule for examinations: Individual body weights were obtained on days 0, 6, 9, 12, 16, and 20 of gestation.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule: feed consumption was measured for gestation days 0–6, 9–12, 12–16, and 16–20.
POST-MORTEM EXAMINATIONS: Yes
- Sacrifice: Dams that aborted were sacrificed at the time. Regular sacrifices were performed on gestation day 20 by carbon dioxide inhalation.
OTHER: Blood evaluations were not performed on the main study animals to avoid undue stress. - Ovaries and uterine content:
- The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: fetal sex ratios and fetal body weights - Fetal examinations:
- - External examinations: Yes (litters and fetus)
- Soft tissue examinations: Yes (litters and fetus)
- Skeletal examinations: Yes (litters and fetus)
- Head examinations: No data
Fetuses were examined for external, internal (visceral), and skeletal abnormalities. Developmental malformations and variations were classified based on severity of anatomical changes and the extent of potential interference with organ and/or body functions. A fetal malformation was considered a permanent alteration that would adversely affect survival, growth, development, or functional competence. Fetal variations were considered to represent a delay in development, a transitory alteration or a permanent alteration not believed to adversely affect the survival, growth, development, or functional competence. Approximately 1/2 of fetuses were fixed in Bouin’s solution for subsequent visceral examination by the method of Wilson under low power microscope and 1/2 were eviscerated, fixed in 95% isopropyl alcohol, macerated in 1.5% aqueous potassium hydroxide, stained with Alizarin Red S, cleared in 25% aqueous glycerin and skeletal examinations performed under low power magnification. - Statistics:
- All analyses were two-tailed with a minimum significance level of 5%. One way analysis of variance followed by Dunnett’s test was used to analyze maternal and fetal data including body weights, food consumption, and number of viable fetuses, implantation sites, and corpora lutea. Mann–Whitney U test was used to compare post implantation loss, dead fetuses, and resorption. Fetal sex ratios were analyzed using the Chi-Square test. Fisher’s Exact test was used to analyze the incidence and number of fetal malformations and variations utilizing the dam or dose (litter) as the experimental unit.
- Historical control data:
- (see results below)
Results and discussion
Results: maternal animals
Maternal developmental toxicity
- Details on maternal toxic effects:
- Maternal toxic effects:yes
Details on maternal toxic effects:
MORTALITY: One rat of 60 mg/kg group died on gestation day 3 of an undetermined cause (prior to MEKO administration). The pregnancy status could not be determined. All other rats survived to scheduled sacrifice.
PREGNANCY RATES: The pregnancy rates were 100% in the 600 mg/kg group, 96% in the 200 mg/kg group, and 92% in the control and 60 mg/kg groups.
CLINICAL SIGNS: Dose-dependent clinical signs of toxicity were observed at 200 and 600 mg/kg. Salient treatment-related findings were wobbly gait, general decreased responsiveness, urine stains, and apparent lack of urination control. In addition, weak body tone, coolness to the touch, salivation, and pale-appearing extremities were observed following dosing at the 600 mg/kg level. These clinical signs were generally transient and not observed prior to MEKO administration on the following day. No treatment-related clinical signs were observed in the 60 mg/kg group.
BODY-WEIGHT: Mean maternal body weights and body weight gains were similar between the control and 60 mg/kg groups throughout the study. In the 200 mg/kg group, mean body weights were similar to the control group. A significant reduction in body weight gain during gestation days 9–12 resulted in a significantly reduced weight gain for the entire treatment period (gestation days 6–16). At the 600 mg/kg level, significant body weight losses occurred during gestation days 6–9 and significantly reduced body weight gains were observed from gestation days 9–12. This resulted in a significant reduction in weight gain for the entire treatment period (when adjusted for gravid uterus weight). These changes also resulted in significantly lower mean body weights on gestation days 9, 12, 16, and 20 at this level. After the cessation of dosing, body weight gains were significantly increased indicating a recovery from treatment with the test article.
FEED CONSUMPTION: At the 60 mg/kg dose level was similar to controls. In the other two dose groups, there were statistically significant reductions in feed consumption at varying intervals during MEKO administration which resulted in an overall decline. However, following cessation MEKO administration, feed consumption was similar to controls, but with an apparent increase on a gm/kg/day basis as a result of lower mean body weights.
NECROPSY: Enlarged spleens in all surviving dams at the 60, 200, and 600 mg/kg levels.
Effect levels (maternal animals)
open allclose all
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- > 600 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Basis for effect level:
- other: developmental toxicity
- Key result
- Dose descriptor:
- LOAEL
- Effect level:
- 60 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Basis for effect level:
- other: maternal toxicity
Results (fetuses)
- Details on embryotoxic / teratogenic effects:
- Embryotoxic / teratogenic effects:no effects
Details on embryotoxic / teratogenic effects:
OBARIES AND UTERINE CONTENT: There were no statistically significant differences between the control in the number of corpora lutea, implantation sites, viable fetuses, resorptions, fetal sex ratios, and fetal body weights. A slight increase (not statistically significant) in the mean number of early resorptions and post-implantation loss in the 600 mg/kg dose group was within the historical range of the laboratory.
FETUS EXAMINATIONS: No treatment-related fetal malformations were noted. One fetus in the 200 mg/kg group was observed to have an omphalocele. All other fetuses in the control and treatment groups were observed to be externally normal. No visceral or skeletal malformations were observed. Slight but not statistically significant increases in 7th cervical ribs and bent ribs were observed in the 600 mg/kg group, and 60, 200, and 600 mg/kg groups, respectively. Statistically significant decreases were observed in the number of litters at the 600 mg/kg level with sternebrae #5 and/or #6 unossified and reduced ossification of the 13th ribs (not considered biologically meaningful).
Effect levels (fetuses)
- Key result
- Dose descriptor:
- NOAEL
- Effect level:
- > 600 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: Based on no dose-related gestational effects, malformations or developmental variations at the highest dose level.
Fetal abnormalities
- Abnormalities:
- not specified
Overall developmental toxicity
- Developmental effects observed:
- not specified
Any other information on results incl. tables
Preliminary Dose Range-Finding Study results:
All rats survived treatment. Pregnancy was found to be 100% except for 83.3% (5/6) at the 100 mg/kg level. No treatment-related changes were observed at 25, 100, and 200 mg/kg. Clinical signs of toxicity were at the 400 mg/kg level. These findings included wobbly gait, weak body tone, and general decreased responsiveness. The signs were transient and not observed prior to MEKO administration on the following day. Mean body weights and body weight gains in dams were generally comparable between the control, 25, 100, and 200 mg/kg levels. Slight body weight losses occurred at 400 mg/kg during gestation days 6–9. Dose-dependent increases in the percentage of reticulocytes and methemoglobin levels occurred in dams at all dose levels tested. The increases in reticulocytes were noted in dams at 200 and 400 mg/kg on gestation days 7, 12, 16, and 20 and at 25 mg/kg and 100 mg/kg on gestation days 12, 16, and 20. The increases in methemoglobin occurred at each interval tested at 25, 100, 200, and 400 mg/kg. At study termination, the methemoglobin levels were considerably lower than at the end of the treatment period indicating recovery was taking place. Necropsy findings included enlarged and blackish-purple spleens at 100, 200, and 400 mg/kg. Spleen adhesions were also observed in one animal at 400 mg/kg. All dams in the 25 mg/kg group were normal internally. All gestational parameters evaluated during Cesarean section observations including viable fetuses, early and late resorptions, fetal sex ratios, gravid uterus weights and fetal body weights were comparable between the control and treatment groups. No fetal external malformations or developmental variations were observed at any group.
Applicant's summary and conclusion
- Conclusions:
- NOAEL for developmental toxicity after a maternal oral exposure of methyl ethyl ketoxime was determined to be > 600 mg/kg bw/day in rats under test conditions.
- Executive summary:
A Prenatal Developmental Toxicity Test was performed on methyl ethyl ketoxime in Sprague-Dawley rats according to EPA OTS 798.4900 Following preliminary dose range finding studies, groups of 25 pregnant rats were dosed by gavage with aqueous solutions of methyl ethyl ketoxime at 0 (control), 60, 200, or 600 mg/kg on gestation days 6–15. Several parameters were periodically observed, such as body weight, feed consumption, clinical pathology, ovaries and uterine content and fetal morphology. Dose dependent clinical signs of maternal toxicity including reduced body weight gains were noted at 200 and 600 mg/kg. At 60 mg/kg and above enlarged spleens were observed at necropsy. The preliminary study found methemoglobin formation and reticulocytosis indicative of anemia at these dose levels. No treatment-related gestational effects, malformations or developmental variations were observed in the rats. MEKO was not considered to have produced any treatment-related gestational effects and therefore, the NOAEL for developmental toxicity of methyl ethyl ketoxime was determined to be > 600 mg/kg bw/day in rats under test conditions.
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.