Phenmedipham

300.31

300.31

237-199-0

UJE31KXP78

DTXSID1024255

Colorless crystals

2924299038

76.7

4.42

Phenmedipham appears as colorless crystals or white powder. (NTP, 1992)

0.25-0.30 g/cu c at 20 deg C

143 °C

441.54°C (rough estimate)

100 °C

1.6240 (estimate)

H2O: <0.1 g/100 mL at 21 ºC;4.7 MG/L WATER; ABOUT 200 G/KG IN ACETONE, CYCLOHEXANONE; ABOUT 50 G/KG IN METHANOL; 20 G/KG IN CHLOROFORM; 2.5 G/KG IN BENZENE; ABOUT 500 MG/KG IN HEXENE AT ROOM TEMP

0-6°C

1.3 nPa at 25 deg C

Oral-Rat LD50: 4000 mg/kg; Oral-Mouse LD50: 8000 mg/kg

Combustion produces toxic nitrogen oxide and sulfur oxide gas

ODORLESS

Henry's Law constant= 8.41X10-13 atm-cu m/mole (est)

Insoluble in water.

Carbamates

PHENMEDIPHAM is a carbamate ester. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates. This compound is incompatible with alkaline preparations. (NTP, 1992)

Non-corrosive

UN 3077

2

50/53

60-61

FD9050000

N

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

SHELF LIFE OVER 1 YR

P273-P501

H410

Flash point data for this chemical are not available, however it is probably combustible. (NTP, 1992)

|Warning|H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|H400 (99.7%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|Aggregated GHS information provided by 338 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]|H373: Causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]|P260, P314, and P501

Fires involving this compound can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)

SMALL SPILLS AND LEAKAGE: If a spill of this chemical occurs, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with acetone and transfer the dampened material to a suitable container. Use absorbent paper dampened with acetone to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with acetone followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned. STORAGE PRECAUTIONS: You should store this material in a refrigerator. (NTP, 1992)

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)|Wear goggles to prevent splashing into eyes.

DO NOT BREATHE SPRAY MIST. DO NOT EAT, DRINK, OR SMOKE WHILE SPRAYING.

practically nontoxic

LD50 Dog oral 4000 mg/kg|LD50 Guinea pig oral 4000 mg/kg|LD50 Chicken oral 3000 mg/kg|LD50 Rat percutaneous 4000 mg/kg|LD50 Rat oral >8000 mg/kg

Betanal's use as a post-emergence herbicide(1-2) releases the compound directly to the environment through applications in sprays, concentrates and other routes of application(SRC).

In soils, 71-86% of amount determined 1 day after treatment was degraded in 90 days.|TERRESTRIAL FATE: Betanal can degrade in soil through microbial degradation and chemical hydrolysis. Biological screening studies have demonstrated that betanal will biodegrade(1-2); in one study, chemical degradation was faster than microbial degradation(2). Betanal is susceptible to alkaline hydrolysis. The following aqueous hydrolysis half-lives have been reported for buffered betanal solutions at 22 °C(3): 70 days at pH 5, 24 hr at pH 7 and 10 min at pH 9(3). The second-order hydrolysis rate constant was experimentally determined to be 106 L/mol-sec at 25 °C(4) which corresponds to half-lives of 7.5 days at pH 6, 18 hr at pH 7 and 1.8 hr at pH 8(4,SRC). Therefore, degradation rates can be expected to increase with increasing pH; microbial degradation will become more important as the acidity increases(SRC).|TERRESTRIAL FATE: The US Dept of Agric's Pesticide Properties Database lists a soil half-life of 30 days for betanal(1). At recommended application rates, the resultant avg persistence is reported to be 25 days(4). In slightly acidic soils of low humus content, half-lives of 28-55 days were observed(2). Using an alkaline soil (pH 8) and C14-labelled betanal, the concn of betanal dropped from 89.6% at time zero to approximately 11% in 32 days(3); methyl hydroxyphenylcarbamate was the major metabolite with small amounts of m-aminophenol(3). Betanal is reported to remain in the top layers of soil (0 to 2 inches) after herbicidal applications(4) and its Koc value of 2400(1) would suggest a low potential to leach(SRC).|AQUATIC FATE: Betanal can degrade in water through microbial degradation and chemical hydrolysis. Biological screening studies have demonstrated that betanal will biodegrade(1-2). Betanal is susceptible to alkaline hydrolysis. The following aqueous hydrolysis half-lives have been reported for buffered betanal solutions at 22 °C(3): 70 days at pH 5, 24 hr at pH 7 and 10 min at pH 9(3). The second-order alkaline hydrolysis rate constant was experimentally determined to be 106 L/mol-sec at 25 °C(4) which corresponds to half-lives of 7.5 days at pH 6, 18 hr at pH 7 and 1.8 hr at pH 8(4,SRC). Therefore, degradation rates in water may increase with increasing pH; microbial degradation may become more important as the acidity increases(SRC). Based upon a Koc value of 2400(5), some partitioning from the water column to sediment and suspended material may occur(SRC). Aquatic volatilization is not expected to be important fate process(SRC).|For more Environmental Fate (Complete) data for BETANAL (9 total), please visit the HSDB record page.

The rate constant for the vapor phase reaction of betanal with photochemically produced hydroxyl radicals has been estimated to be 1.91X10-10 cu cm/molecule-sec at 25 °C which corresponds to an atmospheric half-life of about 2 hours at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The following aqueous hydrolysis half-lives have been reported for buffered betanal solutions at 22 °C(2); 70 days at pH 5, 24 hr at pH 7 and 10 min at pH 9(2). The second-order alkaline hydrolysis rate constant was experimentally determined to be 106 L/mol-sec at 25 °C(3) which corresponds to halves-life of 7.5 days at pH 6, 18 hr at pH 7 and 1.8 hr at pH 8(3,SRC); the hydrolysis products include methyl N-3(hydroxyphenyl) carbamate and m-toluidine via N-(m-tolyl)carbamic acid(3). Betanal absorbs UV light in the environmental solar spectrum(4); therefore, photodegradation may have some importance in the environment(SRC).

Based upon a water solubility of 4.7 mg/L at 25 °C(1), the BCF of betanal can be estimated to be 260 from a regression derived equations(2,SRC). This BCF value suggests that bioconcentration in aquatic organisms may occur(SRC).

2.40e+03 L/kg|Molecular modelling techniques used to estimate the mobility of organic chemicals in soils were evaluated. The effect of molecular structure & water solubility on mobility is discussed.|Using several different soils, an Rf value of 0.17 was measured via soil thin-layer chromatography which is indicative of low soil mobility(1). Based upon a water solubility of 4.7 mg/L at 25 °C(2), the Koc of betanal can be estimated to be about 1860 from a regression derived equation(3,SRC). The US Dept Agric's Pesticide Properties Database lists a Koc value of 2400 for betanal(2). According to a suggested classification scheme(4), these Koc values suggest that betanal has low mobility in soil(SRC). Betanal is reported to remain in the top layers of soil (0 to 2 inches) after herbicidal application(5). In a field study in sugar beet soil, applications of betanal remained in the upper 10 cm of soil 2 months after application(6).

Based upon a vapor pressure of 1.0X10-11 mm Hg(1 and a water solubility of 4.7 mg/L at 25 °C(1), the Henry's Law constant for betanal can be estimated to be 8.41X10-13 atm-cu m/mole(SRC). This value of Henry's Law constant indicates that betanal is essentially nonvolatile from water(3).

SURFACE WATER: Betanal has been qualitatively detected in lowland river waters collected in Britain and West Germany (concns, dates, sites not reported)(1).|GROUNDWATER: During various sampling periods in 1984, water samples were collected from 206 waterwork wells in Germany and analyzed from 35 different pesticides(1); betanal was not detected above a detection limit of 0.05 ug/L(1).

Occupational exposure to betanal occurs through dermal contact and inhalation of sprays, especially to workers applying the compound as a herbicide(1).

Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE. (See all compounds classified as Herbicides.)

In rats, dogs & humans ... phenmedipham ... /is/ readily absorbed ... .|RECOVERY OF /ORALLY/ ADMIN DOSE /TO RATS/ IN URINE & FECES, AT 72 HR AFTER TREATMENT, WAS ... 99% ... URINE ... PRIMARY ROUTE OF ELIMINATION, WITH 80% ... EXCRETED VIA URINE IN INITIAL 24 HR ... TRACE AMT OF RADIOLABEL ... IN KIDNEY ... 0.039 PPM ... ALL OTHER TISSUES FELL BELOW THIS LEVEL.|It is absorbed through leaves & has little action by way of soil & roots.

WHEN ADMIN TO WHITE RATS, PHENMEDIPHAM ... RAPIDLY METABOLIZED ... HYDROLYSIS YIELDED METHYL N-(3-HYDROXYPHENOL) CARBAMATE (MHPC) ... HYDROXYPHENYLCARBAMATES FORMED ... DEGRADED TO M-AMINOPHENOL WHICH WAS ACETYLATED TO ... 3-HYDROXYACETANILIDE. THESE METABOLITES WERE THEN CONJUGATED AS GLUCURONIDES & SULFATES.|BETANAL ... WAS RAPIDLY METABOLIZED BY RATS TO CORRESPONDING PHENOL ... (60-70%)(WHICH WAS PARTLY CONJUGATED) & M-HYDROXYANILINE, WHICH WAS EXCRETED AS M-HYDROXYACETANILIDE ... (2%).

BETANAL EXERTS ITS HERBICIDAL ACTION BY DISRUPTING PHOTOCHEMICAL REACTIONS. MAJOR CHANGES INVOLVED PHOSPHORYLATION & ITS RELATED NONCYCLIC ELECTRON TRANSPORT.|PHENMEDIPHAM IS STRONG INHIBITOR OF HILL REACTION /IN PLANTS/.|At concn near 2X10-4 M, phenmedipham inhibited electron transfer in potato and mung bean mitochondria. The inhibition seemed to be localized in the flavoprotein region. It affected preferentially the exogenous nicotinamide-adenine dinucleotide (NADH) dehydrogenase, in potato mitochondria. Succinate dehydrogenase was less inhibited. Photosynthesis was completely inhibited by 2X10-7 M phenmedipham.

SYMPTOMS: Symptoms of exposure to this compound include photodermatitis, hypoactivity, salivation, muscle weakness, nasal discharge, and labored breathing. ACUTE/CHRONIC HAZARDS: This compound may cause skin irritation. (NTP, 1992)

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment. INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing. INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

Treatment /of phenmedipham poisoning/ is symptomatic.

Two farmers came separately to the same department of dermatology for diagnosis. One had used phenmedipham for 8 or 9 yr without recognized difficulty in spite of a long history of photodermatitis. However, what was considered an exacerbation of photodermatitis began only a few days after he used phenmedipham in 1978, and a patch test required 14 days to subside. The second farmer presented with a severe, spreading, bullous dermatitis of both hands a few days after he used the compound. He too had used it for 8 or 9 yr without difficulty, but a patch test was positive.

Betanal

'BETANAL' (157 G AI/L); IN UNITED KINGDOM 'BETANAL E' (120 G/L). TECHNICAL PRODUCT IS MORE THAN 95% PURE.|EMULSIFIABLE CONCENTRATES 16.7% (WT/VOL) TECHNICAL MATERIAL, 15.9% (WT/VOL) TECHNICAL MATERIAL.

US PATENT/S/ 3,404,075 & 3,692,820.|IT IS APPLIED EITHER BROADCAST OR AS BAND TREATMENT. RATES: BROADCAST--1 TO 1.25 LB/ACRE AT COTYLEDON TO TWO TRUE LEAF STAGE WEEDS. 1.25 TO 1.5 LB/ACRE AT 2 TO 4 TRUE LEAF STAGE OF WEEDS. USUAL CARRIER: PHENMEDIPHAM IS APPLIED DILUTED WITH WATER AT BROADCAST RATE OF 20 GALLONS/ACRE.

ACTIVE INGREDIENT IN BETANAL IS DETERMINED BY HYDROLYSIS & STEAM DISTILLATION FOLLOWED BY BROMOMETRIC TITRATION.|The use of coupled-column HPLC and MS using field desorption and fast atom bombardment ionization for the separation and identification of organics isolated from river and drinking water was reported. Phenmedipham was identified in river water using field desorption MS.|The adsorption properties of Tenax were studied to test the possibility of concentration and recovery of pollutant substances. Pesticides of various classes (chlorinated, phosphorated, carbamates, carbonates) and other organic toxicants having different volatility were employed as substances to be concentrated. They were present in water at 0.1 ppb. Recovery was made by solvent extraction or by thermoelution. Revelation and quantitative analysis were performed by GC and by high pressure TLC.|Simultaneous determination of several carbamate pesticides including betanal in fruits and vegetables by multistage HPLC in a single run.

Agrochemicals -> Herbicides|Pharmaceuticals|Herbicides|Environmental transformation -> Pesticides (parent, predecessor)

Phenmedipham has known environmental transformation products that include 3-aminophenol, 3-aminotoluene, and methyl-3-hydroxylphenylcarbamate.|Phenmedipham has known environmental transformation products that include 3-[(methoxycarbonyl)amino]phenyl(3-hydroxyphenyl)carbamate (M1), APMP, MHPC, m-aminophenol (M6), and m-toluidine .