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Chemical Identifying Information for Carbaryl
CAS NUMBER: 63-25-2
SYNONYMS: Carbamic acid, methyl-, 1-naphthyl ester; Methylcarbamic acid-1-naphthyl ester; 1-Naphthyl methylcarbamate; Sevin
NIOSH Registry Number: FC5950000
CHEMICAL FORMULA: C12H11NO2
MOLECULAR WEIGHT: 201.24 [702]
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PHYSICAL DESCRIPTION: White crystalline solid, essentially odorless [705]
SPECIFIC GRAVITY: 1.23 @ 20C/4C [704]
MELTING POINT: 142 C [705]
BOILING POINT: Decomposes [702]
SOLUBILITY: Water: 40 mg/L [702] Water: 40 ppm @ 30 C [709] Soluble in most organic solvents [709]
OTHER PHYSICAL DATA: Vapor pressure: <0.005 mmHg @ 26 C [705] Vapor pressure: 0.002 mmHg @ 40 C [709] Melting Point: 145 C [702]
HAP WEIGHTING FACTOR: 1 [713]
VOLATILITY: Vapor Pressure: 0.002 mmHg @ 40 C [709]
FIRE HAZARD: Flash Point: Not applicable
Flammability: Noncombustible solid, but may be dissolved in flammable liquids [704].
Autoignition temperature: Not available
LEL: Not applicable UEL: Not applicable
REACTIVITY: Incompatible or reacts with strong oxidizers such as chlorates, bromates, and nitrates [704].
STABILITY: When heated to decomposition it emits toxic fumes of NOx [703].
USES: Insecticide (trade name "SEVIN") [709].
COMMENTS: Noncorrosive; hydrolyzes rapidly in alkaline solutions [709].
ACUTE/CHRONIC HAZARDS: A poison by ingestion, intravenous, intraperitoneal, and possibly other routes; human mutagenic data exists. An experimental carcinogen, teratogen, and tumorigen; produces experimental reproductive effects. An eye and severe skin irritant; absorbed by all routes; skin absorption is slow with no accumulation in tissue. A reversible cholinesterase inhibitor. [703] Targeted organs include the respiratory system, central nervous system, cardiovascular system, and skin. [704] When heated to decomposition, emits toxic fumes of NOx. [703]
SYMPTOMS: Symptoms of exposure to carbaryl (trade name "Sevin") may include miosis, blurred vision, tearing; nasal discharge, salivation; sweat; abdominal cramps, nausea, vomiting, diarrhea; tremor; cyanosis; convulsions; and skin irritation. [704] Symptoms include blurred vision, headache, stomach ache, and vomiting. Symptoms similar to but less severe than those due to parathion. [703]
Numbers in brackets [ ] are reference numbers in the source of this information.
Source: Instant EPA's Air Toxics, Copyright 1994 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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EPA's IRIS is the world's most comprehensive toxicology database. Chemical entries often range from 20 to 50 pages of information. The information below represents a small selection of the data involving carcinogenicity in Section II of IRIS. Many of the technical terms are hyperlinked with explanations in Instant EPA's IRIS from which the following exerpts were taken but space limitations preclude that convenience here.
I.A.2. PRINCIPAL AND SUPPORTING STUDIES (ORAL RfD)
Carpenter, C.P., C.W. Weil, P.E. Polin, et al. 1961. Mammalian toxicity of 1-naphthayl-N-methylcarbamate (Sevin insecticide). J. Agric. Food Chem. 9: 30-39. Groups of 20 CF-N rats/sex were fed carbaryl at 0, 50, 100, 200, or 400 ppm of diet for 2 years. Food consumption and body weight records were maintained. Interim sacrifices (4-8 animals) from concurrent auxiliary groups were performed at 6, 9, and 12 months for organ weight comparisons and histopathologic analysis. Hematologic analyses were done at irregular intervals throughout the study. Surviving animals were sacrificed at 2 years with gross and histopathologic examinations performed. The only noteworthy effects reported were slight histopathologic changes in the kidneys and liver at the high-dose level. Diffuse cloudy swelling of renal tubules was observed at 1 and 2 years. A statistically significant increase in cloudy swelling of the hepatic cords was also observed after 2 years. Based on body weight and food consumption data, the LOAEL of 400 ppm was equivalent to a dose of 15.6 mg/kg bw/day. The NOAEL established was 9.6 mg/kg bw/day.
I.A.3. UNCERTAINTY AND MODIFYING FACTORS (ORAL RfD)
UF -- UF = 10a x 10h. The UF of 100 includes uncertainties in interspecies and intrahuman variability.
MF -- None
I.A.4. ADDITIONAL COMMENTS (ORAL RfD)
Effect and no-effect levels (14 and 7 mg/kg/day, respectively) similar to those found in the critical study were observed for rat body weight reduction and cholinesterase inhibition in a 1-year study. In subchronic rat studies, higher dose levels (85-200 mg/kg/day) caused kidney toxicity and biochemical changes. Kidney lesions were observed in dogs fed carbaryl at 5 mg/kg/day for 1 year; however, the effect was not clearly associated with treatment, since the lesions appeared in control animals but not in lower dose groups.
Carbaryl was teratogenic for several species, with widely varying NOELs. The lowest effect levels of 5-6 mg/kg were observed for dogs, with NOELs of 2-3 mg/kg. Other LOELs were higher than the established chronic LOAEL of 15.6 mg/kg/day. Carbaryl was not teratogenic for monkeys at 20 mg/kg. The dog studies were judged inappropriate for human health risk assessment because of differences in the metabolism of carbaryl between dogs and humans.
I.A.5. CONFIDENCE IN THE ORAL RfD
Study -- High
Data Base -- Medium
RfD -- Medium
The principal study was well designed and clearly reported with unequivocal effect levels established. The data base is moderately supportive of the nature of the critical effect, if somewhat sparse. The principal problem is the observation of teratogenicity in dogs at lower doses. Because the significance of these data cannot be discounted entirely, confidence in the RfD should be considered medium to low.
I.A.6. EPA DOCUMENTATION AND REVIEW OF THE ORAL RfD
Source Document -- U.S. EPA, 1984
Limited Agency review of 1984 Health and Environmental Effects Profile with the help of two external scientists.
Other EPA Documentation -- None
Agency Work Group Review -- 05/31/85
Verification Date -- 05/31/85
I.A.7. EPA CONTACTS (ORAL RfD)
Joan Dollarhide / NCEA -- (513)569-7553
Source: Instant EPA's IRIS, Copyright 1996 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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The table below was scanned from Instant Gloves + CPC Database. It contains information on the breakthrough times and permeation rates for Carbaryl tested against many manufacturer's models of CPC. If you are not familiar with the chemical permeation test procedures and the interpretation of breakthrough time and permeation rate data then you will find the Permeation Index Number to be useful in helping you make selections.
The Permeation Index Number Appears in the fourth column from the left in the table of data below. It's interpretation with the data in the table is:
Index Number .... Level of Permeation Rate
0 .... None or Very Low - - this is the Best Selection.
1 .... Very Low - - this is the Next Best Selection.
2 .... Low - - Sometimes Satisfactory but change garment when exposed.
3 .... Moderate Poor Choice - - Change the garment quickly when exposed.
4 .... High - - Very Poor Choice; Splashes Only, Change Quickly When Exposed.
5 .... Very High - - Dangerous Choice
Additional Information on Permeation Index Numbers
Numbers in the last column are reference numbers in the source of this information.
Source: Instant Gloves + CPC Database, Copyright 1996 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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MATRIX: This method is used to analyze semivolatile organic compounds in extracts from all types of solid waste matrices, soils and groundwater. Although surface waters are not specifically mentioned, it is also applicable to water samples from rivers, lakes, etc.
APPLICATION: This method covers 259 semivolatile organic compounds.
Samples are extracted with methylene chloride under acid and then under basic conditions and the concentrated extracts are analyzed by capillary GC-MS. The amount of the surrogates and matrix spiking compounds added to the sample should result in a final concentration of 100 ng/mL of each base/neutral analyte and 200 ng/mL of each acid analyte in the extract to be analyzed (assuming a 1 mL injection).
A 1 L sample is adjusted to pH <2 with sulfuric acid and 1.0 mL of a surrogate standard mixture is added to it. The sample is extracted with methylene chloride in a continuous extractor for 18-24 hours. Then the pH of the aqueous phase is adjusted to >11 with sodium hydroxide and the sample is reextracted with methylene chloride for another 18-24 hours. The extract is dried by passing it through a column of anhydrous sodium sulfate and then concentrating it to 1.0 mL.
Approximately 30 g of sample is rapidly weighed to avoid loss of the more volatile compounds. Nonporous or wet samples (gummy or clay type) must be mixed with anhydrous sodium sulfate until the sample is free flowing. Surrogate standards (1.0 mL) are added to all samples, spikes, standards, and blanks. The sample is extracted ultrasonically 3 times with a 1:1 mixture of methylene chloride:acetone and the extract is dried by passing it through a column of anhydrous sodium sulfate and then concentrating it to 1.0 mL.
INTERFERENCES: Cross contamination can occur whenever high-concentration and low-concentration samples are sequentially analyzed. Whenever an unusually concentrated sample is encountered, it should be followed by the analysis of solvent to check for cross contamination.
INSTRUMENTATION: A gas chromatograph with a mass spectrometer (GC/MS) and a data system are required. The GC column is a 30 m x 0.25 mm ID (or 0.32 mm ID) 1 mm film thickness silicone-coated fused silica capillary column. A continuous liquid-liquid extractor equipped with Teflon or glass connection joints and stopcocks requiring no lubrication, a Kuderna-Danish concentrating apparatus, and an ultrasonic disrupter with a minimum power wattage of 300 watts with pulsing capability are also required.
RANGE: Not listed
Estimated Quantitation Limit, groundwater: 10 mg/ L
Estimated Quantitation Limit, soil/sediment: Not listed
PRECISION: Not listed
ACCURACY: Not listed
SAMPLING METHOD: Pre-wash sampling bottles with detergent, rinse with distilled water and methanol or isopropanol. Flush glassware immediately before use with some of the same solvent that will be used in the analysis.For liquid samples use a 1 gallon or a 2 1/2 gallon amber glass bottle with a screw-top Teflon-lined cover. For soils, sediments or sludges use an 8 oz. widemouth glass bottle with a screw-top Teflon-lined cover.
STABILITY: Cool samples to 4°C. If residual chlorine is present, add 3 mL of 10% sodium thiosulfate per gallon and cool to 4°C.
M.H.T.: Liquid samples must be extracted within 7 days and extracts analyzed within 40 days. Soils, sediments, and sludges may be stored for a maximum of 14 days.
QUALITY CONTROL: A methylene chloride solution with 50 ng/mL of decafluorotriphenylphosphine (DFTPP) is used for tuning the GC/MS system each 12 hour shift. A system performance check also must be made during every 12 hour shift and must be acceptable before analysis begins. A standard containing 50 ng/mL each of 4,4'-DDT, pentachlorophenol, and benzidine is required to verify injection port inertness and GC column performance. A calibration standard at mid-concentration, containing each compound of interest, including all required surrogates, must be performed every 12 hours during analysis.
After the system performance check is met, Calibration Check Compounds (CCCs) are used to check the validity of the initial calibration. If the difference for any compound is greater than 20%, this is a warning limit. If the difference for each CCC is greater than 30%, the initial calibration is notvalid.
The internal standard responses and retention times in the calibration check standard must be evaluated immediately after or during data acquisition. If the retention time for any internal standard changes by more than 30 seconds from the last check calibration (12 hours), the chromatographic system must be inspected for malfunctions and corrections must be made, as required. If the electron ionization current plot (EICP) area for any of the internal standards changes by a factor of two (-50% to +100%) from the last daily calibration standard check, the mass spectrometer must be inspected for malfunctions and corrections must be made, as appropriate.
Before processing any samples analysis of a reagent water blank must demonstrate that interferences from the analytical system, glassware, and reagents are under control. Each time a set of samples is extracted or there is a change in reagents, a reagent water blank should be analyzed as a safeguard against chronic laboratory contamination. For each analytical batch (up to 20 samples), a reagent blank, matrix spike and matrix spike duplicate/duplicate must be analyzed.
A QC reference sample concentrate containing each analyte at a concentration of 100 mg/ L in methanol is required. If prepared by the laboratory, the QC reference sample concentrate must be made using stock standards prepared independently from those used for calibration. QC reference samples also must be prepared by the lab at a concentration of 100 mg/ L, by addition of the QC concentrate to organic-free reagent water.
REFERENCE: U.S. EPA Method 8270, Revision 2. Test Methods for Evaluating Solid Waste (SW-846). U.S. EPA November 1990. Office of Solid Waste, Washington, D.C.
MATRIX: This method is applicable to the determination of certain N-methylcarbanoyloximes and N-methylcarbamates in finished drinking water and groundwater.
APPLICATION: Method 531 covers 10 N-methylcarbamoyloximes and N-methylcarbamate compounds. Samples are adjusted to pH 3.0 ± 0.2 with 2.5M monochloroacetic acid buffer and an internal standard is added. A 5 mL aliquot is filtered using a syringe and 400 mL of the sample is analyzed using HPLC with gradient elution. After elution from the HPLC column, the analytes are hydrolyzed with 0.05N sodium hydroxide at 95°C in a post column reactor. The methyl amine formed during hydrolysis is reacted with o-phthalaldehyde and 2-mercaptoethanol to form a highly fluorescent derivative which is detected by a fluorescence detector.
INTERFERENCES: Method interferences may be caused by contaminants in solvents, reagents, glassware, etc. Cross contamination may occur when a sample containing low concentrations of analytes is analyzed immediately following a sample containing relatively high concentrations. Matrix interferences may be caused by contaminants that are present in the sample and will vary considerably from source to source, depending on the water sampled.
INSTRUMENTATION: High Performance Liquid Chromatograph (HPLC) capable of
performing binary linear gradients at a constant flow rate and equipped with a
post column reactor and a fluorescence detector.
Column #1: 150 mm x 3.9 mm ID stainless steel packed with 4 mm NovaPak C18;
Column #2: 250 mm x 4.6 mm ID
stainless steel packed with 5 mm Beckman Ultrasphere ODS;
Column #3: 250 mm x 4.6 mm ID stainless steel packed with 5 mm Supelco LC-1.
RANGE: Not listed
MDL: 2.0 mg/ L @ 10 mg/ L
PRECISION: 5.8% Rel. Std. Deviation
ACCURACY: 97% of true value
SAMPLING: Grab samples (50 mL) are collected in 60 mL glass vials (prewashed with detergent and hot tap water, rinsed with reagent water, and dried in an oven at 450°C for 1 hour) with screw caps equipped with a PTFE-faced silicon septa.
STABILITY: Add 1.8 mL of monochloroacetic acid buffer to the sample bottle to adjust sample to pH 3. If residual chlorine is present, add 80 mg of sodium thiosulfate per liter of sample to the sample bottle prior to collection. After collection, seal bottle and shake vigorously for 1 minute. Cool sample to 4°C immediately. Samples must be refrigerated at 4°C from time of collection to storage. Samples must be stored at -10°C until analyzed.
M.H.T. = 28 days when adjusted to pH 3 and stored at -10°C.
QUALITY CONTROL: Minimum QC requirements are initial demonstration of laboratory capability, determination of surrogate compound recoveries in each sample and blank, monitoring internal standard peak area or height in each sample and blank, analysis of laboratory reagent blanks, laboratory fortified samples, laboratory fortified blanks, and QC samples. All reagents and apparatus must be routinely demonstrated to be free from interferences by running laboratory reagent blanks. Initial demonstration of capability is fulfilled by analyzing four fortified reagent water samples with recovery value for each analyte with the acceptable range (± 30% average recovery). Surrogate recoveries from samples or method blanks must be 70-130%. The internal standard response for any sample chromatogram should not deviate from the daily calibration check standard's internal standard response by more than 30%. Laboratory fortified blanks and sample matrices are used to assess laboratory performance and analyte recovery, respectively. One or more laboratory method blanks should be analyzed following the analysis of a sample with high concentration of analytes.
REFERENCE: U.S. EPA Method 531, Revision 3.0, 1989. Methods for the Determination of Organic Compounds in Drinking Water, EPA/600/4-88/039. U.S. EPA Environmental Monitoring Systems Laboratory, Cincinnati, OH, 45268, USA.
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Generic Name: 1-napthyl N-methylcarbamate
Common Name: carbaryl
Trade Name: Sevin
EPA Shaughnessy Code: 056801
Chemical Abstracts Service (CAS) Number: 63-25-2
Year of Initial Registration: 1958
Pesticide Type: Insecticide
Chemical Family: Carbamates
U.S. and Foreign Producers: Union Carbide, Makteshim Chemical Works, Inc.
2. Use Patterns and Formulations
- Application sites: citrus, pome, stone and berry fruits, forage, field and vegetable crops, nuts, lawns, forests, ornamental plants, rangeland, shade trees, poultry and pets, indoor use
- Types of formulations: baits, dusts, granules, wettable powders, flowables, and aqueous dispersions
- Types and methods of application: ground and aerial
- Application rates: range from 0.53 lbs. a.i./A to 6.4 lbs. a.i./A
- Usual carriers: synthetic clays, talc, various solvents
3. Science Findings
- Based on established tolerances, the theoretical maximum residue contribution (TMRC) for carbaryl residues in the human diet is calculated to be 5.48 mg/day. The acceptable daily intake (ADI) of carbaryl is 0.1 mg/kg/day. The maximum permissible intake (MPI) is 6 mg/day. To provide for conformity between U.S. tolerances for carbaryl and tolerances established by the Codex Alimentarius, Canada and Mexico, the expression of the U.S. tolerances for carbaryl will be changed to omit reference to 1-naphthol.
- A 1-year dog feeding study is being requested in order to determine the effects of carbaryl on kidney dysfunction. The results of these data may require that the ADI for carbaryl be recalculated.
- U.S. tolerances for most raw agricultural commodities are supported by current residue chemistry data. In some cases, however, more data are required.
- Summary Science Statement
- Carbaryl has moderate to low mammalian toxicity. It is not considered to be an oncogen. It is a weak mutagen. Available data indicates that carbaryl has only low teratogenic potential. Long term dietary studies in rats and dogs and a short term study in humans (highest dose only) demonstrate an apparent effect on renal function.
- No reentry interval is necessary for carbaryl. Carbaryl is not expected to contaminate groundwater. Data are insufficient to assess the environmental fate of carbaryl.
- Carbaryl is extremely toxic to aquatic invertebrates and certain estuarine organisms. It is extremely toxic to honeybees. It is moderately toxic to both warmwater and coldwater fishes and has only low toxicity to birds.
- A full tolerance reassessment cannot be completed. A 1-year dog feeding study is required, as well as residue data on numerous processed commodities.
4. Summary of Regulatory Position and Rationale
- The Agency has determined that it should continue to allow the registration of carbaryl. Adequate studies are available to assess the acute toxicological effects of carbaryl to humans. None of the criteria listed in section 162.11(a) of Title 40 of the U.S. Code of Federal Regulations have been met or exceeded. However, because of gaps in the data base, a full risk assessment of carbaryl cannot be completed.
- A full tolerance reassessment cannot be completed because of certain residue chemistry and toxicology data gaps, namely a 1-year dog feeding study and the need for residue data on various processed commodities.
- No federal or state reentry intervals have been established for carbaryl or will be established.
- Available data are insufficient to fully assess the environmental fate of carbaryl. The Agency is requesting data to determine if carbaryl will contaminate groundwater.
6. Contact Person at EPA
Jay S. Ellenberger
Product Manager (12)
Insecticide- Rodenticide Branch
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street, S.W.
Washington, DC 20460
Office location and telephone number:
Room 202,
Crystal Mall #2 1921
Jefferson Davis Highway
Arlington, VA 22202
Phone: (703) 557-2386
Source: Instant EPA's Pesticide Facts, Copyright 1996 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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