(4-Chloro-2-methylphenoxy)acetic acid Safety Data Sheets

Acute toxicity - Category 4, Oral

Skin irritation, Category 2

Serious eye damage, Category 1

Hazardous to the aquatic environment, short-term (Acute) - Category Acute 1

Hazardous to the aquatic environment, long-term (Chronic) - Category Chronic 1

If inhaled

Following skin contact

Following eye contact

Following ingestion

no data available

Not combustible. Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire. Risk of fire and explosion if formulations contain flammable/explosive solvents.

In case of fire in the surroundings, use appropriate extinguishing media.

Personal protection: filter respirator for organic gases and particulates adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Personal protection: filter respirator for organic gases and particulates adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Collect and arrange disposal. Keep the chemical in suitable and closed containers for disposal. Remove all sources of ignition. Use spark-proof tools and explosion-proof equipment. Adhered or collected material should be promptly disposed of, in accordance with appropriate laws and regulations.

Handling in a well ventilated place. Wear suitable protective clothing. Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Use non-sparking tools. Prevent fire caused by electrostatic discharge steam.

Provision to contain effluent from fire extinguishing. Separated from strong bases and food and feedstuffs. Store in an area without drain or sewer access. Cool.Keep in well-ventilated area.

Occupational Exposure limit values

Biological limit values

Eye/face protection

Skin protection

Respiratory protection

Thermal hazards

Decomposes on heating. This produces toxic and corrosive fumes including hydrogen chloride and phosgene. The substance is a weak acid. Attacks many metals in the presence of water.

NONVOLATILE

Nonflammable

no data available

Reacts with alkalis to form salts

When heated to decomposition it emits toxic fumes of /hydrogen chloride and nitrogen oxides/.

Acute toxicity

• Oral: LD50 Rat male oral 700 mg/kg
• Inhalation: no data available
• Dermal: LD50 Rat percutaneous >1000 mg/kg

Skin corrosion/irritation

Serious eye damage/irritation

Respiratory or skin sensitization

Germ cell mutagenicity

Carcinogenicity

Reproductive toxicity

STOT-single exposure

STOT-repeated exposure

Aspiration hazard

• Toxicity to fish: LC50 Salmo gairdneri (Rainbow trout) 232 mg/l/96 hr /Conditions of bioassay not specified
• Toxicity to daphnia and other aquatic invertebrates: no data available
• Toxicity to algae: no data available
• Toxicity to microorganisms: no data available

AEROBIC: Microbial degradation of MCPA in soil was followed by measuring radiolabeled 14-CO2 evolution(1); in non-acclimated soil, CO2 evolution reached 40-50% after 78 days of incubation(1). At an initial MCPA concn of 5 mg/kg, CO2 evolution increased markedly after a 2-3 week lag period indicating that microbial adaptation will increase the degradation rate(1); optimum degradation occurred in soil with a moisture content of 0.6 to 1.2 field capacity(1) while degradation in dry soil was negligible(1). The importance of acclimation was demonstrated in soil degradation tests in which degradation in unacclimated soil required 46-82 days, but only 5-14.5 days were required for a subsequent degradation in the same soil(2); sterilization tests (via sodium azide) indicated that all soil degradation was microbial in nature(2). The results of laboratory studies indicated that 14C-labeled MCPA would degrade faster in soils that had received previous applications than in untreated soils(3). Microbial degradation in soil is probably due to hydroxylation with cleavage of the ether linkage (4). The dechlorination of MCPA was indicated as an acid-yielding reaction and was observed to reduce the pH in a mixed culture medium; no degradation occurred in cultures above pH 8.5 and degradation was slower at higher concns(5). In samples of sandy clay soil (pH 5.2, organic matter 6.3%) at field capacity moisture content (18.2%) and incubated at 23 deg C for up to 32 weeks, MCPA, at initial concns of 10, 100, 200 and 500 ppm, degraded more rapidly at the lower concns(6). Respective losses of 40%, 60% and 90% were observed at 2, 8 and 32 weeks; the degradates were identified as 4-chloro-o-cresol, 5-chloro-3-methylcatechol, and 2,6-dimethoxyphenol(6).

A BCF of 1 was determined for trout at MCPA aqueous concns of 10-100 mg/l and using an exposure period of 10-28 day(1). In a model aquatic ecosystem study, BCFs of <1 were measured in fish and snails for the sodium salt of 2-methyl-4-chlorophenoxyacetic acid(2,3). According to a classification scheme(3), these BCF values suggest the potential for bioconcentration in aquatic organisms is low. MCPA is absorbed through leaves or roots and is readily translocated in plants(4).

MCPA adsorption coefficients (Kd) of 0.7 to 1.0 were measured in three soils (loamy sand and sandy loam types)(1); based upon humus contents of 2.4-3.0%(1),the Koc values of the three soils are approximately 60, 52 and 50, respectively. A similar Kd value of 0.4 was observed in a garden soil(2). Using soil thin-layer chromatography, Rf values of 0.6-1.0 were measured for Chillum silt loam (3.1% organic matter), Lakeland sand loam (0.9% organic matter) and Hagerstown silty clay loam (1.4% organic matter)(3,4); these Rf values classify MCPA as mobile in soil(3,4). When MCPA was applied to a rice field, an observed 70% decrease in MCPA was attributed to losses through soil percolation(5). In a laboratory study of leaching columns with either turf grass soil or two subsoils, most of the applied MCPA (95.4-99.0%) eluted with the first 100-ml fraction of leaching water applied to the columns, indicating that MCPA did not bind to the soils(6). According to a classification scheme(7), these Koc values suggest that MCPA is expected to have high mobility in soil.

no data available

Product

Contaminated packaging

no data available

no data available

Information on revision

Abbreviations and acronyms

• CAS: Chemical Abstracts Service
• ADR: European Agreement concerning the International Carriage of Dangerous Goods by Road
• RID: Regulation concerning the International Carriage of Dangerous Goods by Rail
• IMDG: International Maritime Dangerous Goods
• IATA: International Air Transportation Association
• TWA: Time Weighted Average
• STEL: Short term exposure limit
• LC50: Lethal Concentration 50%
• LD50: Lethal Dose 50%
• EC50: Effective Concentration 50%

References

• IPCS - The International Chemical Safety Cards (ICSC), website: http://www.ilo.org/dyn/icsc/showcard.home
• HSDB - Hazardous Substances Data Bank, website: https://toxnet.nlm.nih.gov/newtoxnet/hsdb.htm
• IARC - International Agency for Research on Cancer, website: http://www.iarc.fr/
• eChemPortal - The Global Portal to Information on Chemical Substances by OECD, website: http://www.echemportal.org/echemportal/index?pageID=0&request_locale=en
• CAMEO Chemicals, website: http://cameochemicals.noaa.gov/search/simple
• ChemIDplus, website: http://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp
• ERG - Emergency Response Guidebook by U.S. Department of Transportation, website: http://www.phmsa.dot.gov/hazmat/library/erg
• Germany GESTIS-database on hazard substance, website: http://www.dguv.de/ifa/gestis/gestis-stoffdatenbank/index-2.jsp
• ECHA - European Chemicals Agency, website: https://echa.europa.eu/

Other Information

MCPA is a chlorophenoxy-herbicide which, as a group, has been classified as possibly carcinogenic to humans.Depending on the degree of exposure, periodic medical examination is suggested.Carrier solvents used in commercial formulations may change physical and toxicological properties.