Dichlorprop

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

P264, P264+P265, P270, P280, P301+P317, P302+P352, P305+P354+P338, P317, P321, P330, P332+P317, P362+P364, and P501 (click each P-code to see the statement)

H302 (98%): Harmful if swallowed [Warning Acute toxicity, oral]

H312 (98%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

H318 (98%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

Aggregated GHS information provided per 50 reports by companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H351: Suspected of causing cancer [Warning Carcinogenicity]

H360: May damage fertility or the unborn child [Danger Reproductive toxicity]

H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]

P203, P260, P264, P264+P265, P270, P280, P301+P317, P302+P352, P305+P354+P338, P308+P316, P317, P318, P321, P330, P332+P317, P362+P364, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Seek medical attention if you feel unwell.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention if skin irritation occurs.

Rinse with plenty of water for several minutes (remove contact lenses if easily possible). Refer immediately for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Refer immediately for medical attention.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Refer to the "General First Aid" section. (ERG, 2024)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

CAUTION: Fire involving Safety devices (UN3268) and Fire suppressant dispersing devices (UN3559) may have a delayed activation and a risk of hazardous projectiles. Extinguish the fire at a safe distance.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam.

LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

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

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Personal protection: particulate filter respirator 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.

Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or other waters unless in accordance with the requirements of a National Pollution Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously notifying the local sewage treatment plant authority. For guidance contact your State Water Board or Regional Office of the EPA. /Dichlorprop-p/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

For several good reasons, .... herbicides ... should be handled and applied only with full attention to safety measures that minimize personal contact. Many formulations contain adjuvants (stabilizers, penetrants, surfactants) that may have significant irritating and toxic effects. A number of premixed formulations contain two or more active ingredients; the companion pesticides may be more toxic than the principal herbicide. Good hygienic practice should not be disregarded just because a pesticide is reported to have a high LD50 in laboratory rodents.

Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet. Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put on clean clothing. Users should remove PPE immediately after handling this product. Wash the outside of gloves before removing. As soon as possible, wash thoroughly and change into clean clothing. /Dichlorprop-p/

Do not enter or allow worker entry into treated areas during the restricted entry interval (REI) of 48 hours. ... Do not enter or allow entry until sprays have dried. /Dichlorprop-p/

For more Preventive Measures (Complete) data for DICHLOROPROP (11 total), please visit the HSDB record page.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. For Asbestos, avoid inhalation of dust. Cover spill with plastic sheet or tarp to minimize spreading. Do not clean up or dispose of, except under supervision of a specialist.

SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area.

SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2024)

Provision to contain effluent from fire extinguishing. Store in an area without drain or sewer access. Separated from food and feedstuffs.

If stored below freezing, /it/ may be necessary to warm to 40 °F and agitate before using.

A harmful concentration of airborne particles can be reached quickly when dispersed, especially if powdered.

The substance is corrosive to the eyes. The substance is irritating to the skin.

The substance may have effects on the kidneys. This may result in tissue lesions.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

PPE Requirements Established by the EPA RED for Dichlorprop-p

Table: PERSONAL PROTECTIVE EQUIPMENT FOR DICHLORPROP-P [Table#3254]

Engineering Controls for wettable powder products: Water-soluble packets when used correctly qualify as a closed mixing/loading system under the Worker Protection Standard for Agricultural Pesticides [40 CFR 170.240(d)(4)]. Mixers and loaders using water-soluble packets must : -- wear long-sleeved shirt, long pants, and shoe plus socks, and -- if they are supporting handgun applications, be provided and must have immediately available for use in an emergency, such as a broken package, spill, or equipment breakdown: a NIOSH-approved dust/mist filtering respirator with NIOSH/MSHA approval number prefix TC-21C or a NIOSHapproved respirator with any N, R, P or HE filter. /Dichlorprop-p/

Long-sleeved shirt and long pants. Protective eyewear.

NO open flames. NO contact with hot surfaces.

PREVENT DISPERSION OF DUST! AVOID EXPOSURE OF ADOLESCENTS AND CHILDREN!

Use local exhaust or breathing protection.

Protective gloves.

Wear safety goggles or eye protection in combination with breathing protection if powder.

Do not eat, drink, or smoke during work. Wash hands before eating.

Yellowish to colorless solid. Soluble in organic solvents. Used as an herbicide.

Colorless to yellowish odorless solid; [ICSC] Colorless, white, or brown solid; [HSDB] Light brown powder; [MSDSonline]

ODOURLESS COLOURLESS-TO-YELLOWISH CRYSTALS.

Colorless crystals

WHITE TO TAN, CRYSTALLINE SOLID

ODORLESS

Faint phenolic odor

117.5 °C

117-118 °C

204 °C o.c.

Solubility in water 900 g acid equivalent/L at 20 °C /Dichlorprop-potassium/

Solubility in water, 660 g acid equivalent/L at 20 °C /Sodium salt/

Solubility in water, 740 g acid equivalent/L at 20 °C /Diethanolamine salt/

In acetone 595, isopropanol 510, benzene 85, toluene 69, xylene 51, kerosene 2.1 (all in g/L, 20 °C).

Chloroform 10.8, ether 82.1, ethanol more than 100 (all in g/100 g at 20 °C)

Heptane 0.5% wt/vol

Soluble in ethanol, ether; very soluble in ligroin

In water, 350 mg/L at 20 °C

Solubility in water: none

Relative density (water = 1): 1.4

0.00000008 [mmHg]

7.50X10-8 mm Hg at 20 °C

negligible

log Kow = 3.43

STABLE TO HEAT, & RESISTANT TO REDUCTION, HYDROLYSIS & ATMOSPHERIC OXIDATION.

The acid is very stable, and forms sparingly-soluble, slightly-active salts withheavy metals. The esters are hydrolyzed on warming with acids or alkalis.

When heated to decomposition it emits toxic chloride fumes.

CORROSIVE TO METALS IN PRESENCE OF WATER; CONCN SOLN (480 G AE/L) DOES NOT CORRODE IRON OR TIN PLATE OF IRON IF PH IS GREATER THAN OR EQUAL TO 8.6 & TEMP LESS THAN 70 °C.

pKa = 3.10

Yellowish-to-colorless solid /Technical/

Brown powder with a phenolic odor. MP 114 °C /Technical/

The esters are hydrolyzed on warming with acids or alkalis /Dichlorprop butotyl/

Clear, brown-orange liquid with a faint, slightly pungent odor. MP less than 37 °C; VP 0.45 mPa at 20 °C; Specific gravity about 1.12; Stability Stable after 14 days at 54 °C in the presence of metals. Some degradation over 14 days in sunlight /Dichlorprop-isoctyl/

Fusion temperature

Melting temperature

Nuclear quadrupole resonance spectroscopy

Phase transition

Transition enthalpy

Carcinogens

Herbicides

No rapid reaction with air. No rapid reaction with water.

Acids, Carboxylic

Halogenated Organic Compounds

Aryl Halides

2,4-DP is an organic acid. Neutralizes bases in exothermic reactions.

CDDs cause their toxic effects by binding to the aryl hydrocarbon receptor and subsequently altering the trascription of certain genes. The affinity for the Ah receptor depends on the structure of the specific CDD. The change in gene expression may result from the direct interaction of the Ah receptor and its heterodimer-forming partner, the aryl hydrocarbon receptor nuclear translocator, with gene regulatory elements or the initiation of a phosphorylation/dephosphorylation cascade that subsequently activates other transcription factors. The affected genes include several oncogenes, growth factors, receptors, hormones, and drug-metabolizing enzymes. The change in transcription/translation of these genes is believed to be the cause of most of the toxic effects of CDDs. This includes 2,3,7,8-tetrachlorodibenzo-p-dioxin's carcinogenicity is thought to be the result of its ability to alter the capacity of both exogenous and endogenous substances to damage the DNA by inducing CYP1A1- and CYP1A2-dependent drug-metabolizing enzymes. (L177)

Dichlorprop

Pesticide

Data are for dichlorprop-p, CASRN 15165-67-0, which has an HHBP (2,4-DP-p). Toxicity of dichlorprop-p and the racemic dichlorprop are not significantly different.

Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

2B, possibly carcinogenic to humans. (L135)

It is considered to be a severe eye irritant. There has been concern that chlorophenoxy herbicides including dichlorprop may cause cancer, and in 1987 the International Agency for Research on Cancer (IARC) ranked this class of compounds as group 2B "possibly carcinogenic to humans". The EPA classifies the R-isomer as “Not Likely to be Carcinogenic to Humans.”(L369) Exposure to large amounts of CDDs causes chloracne, a severe skin disease with acne-like lesions that occur mainly on the face and upper body. CDDs may also cause liver damage and induce long-term alterations in glucose metabolism and subtle changes in hormonal levels. In addition, studies have shown that CDDs may disrupt the endocrine system and weaken the immune system, as well as cause reproductive damage and birth defects, central and peripheral nervous system pathology, thyroid disorders, endometriosis, and diabetes. 2,3,7,8-Tetrachlorodibenzo-p-dioxin is also a known human carcinogen. (L177, L178)

The substance can be absorbed into the body by ingestion.

Cough. Sore throat.

Redness.

Redness. Pain. Severe burns.

Sore throat. Headache. Nausea. Vomiting. Diarrhoea.

In addition to chloracne, CDD exposure causes skin rashes, discoloration, and excessive body hair. (L177)

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

LC (rat) > 1,600 mg/m3

LD50: 344 mg/kg (Oral, Rat)

LD50 Rat oral 800 mg/kg

LD50 Rat oral 825 to 1470 mg/kg

LD50 Rat oral 344 mg/kg

LD50 Rat Dermal > 4g/kg /2,4-DP technical/ /From table/

For more Non-Human Toxicity Values (Complete) data for DICHLOROPROP (10 total), please visit the HSDB record page.

Treatment may include washing any areas of contact, GI decontamination if swallowed, administering an IV and forced alkaline diuresis. (L346)

/SIGNS AND SYMPTOMS/ Symptomatology (partly inferential): 1. Fatigue, weakness, anorexia; perhaps nausea, vomiting & diarrhea. 2. Hyporeflexia & lethargy progressing to coma, with constricted pupils (miosis). 3. Flaccid paralysis has been described in one comatose patients & grand mal convulsions with opisthotonos in another, hypertonia with areflexia in a third, & twitching & jerking in a fourth. ... 5. Progressive decline in blood pressure with death in deep coma. The possibility that hyperpyrexia & hypermetabolism may have contributed to the fatal outcome does not appear to have been ruled out (one comatose patient was described as sweating profusely). A terminal pneumonia is likely. 6. Disturbances in body temp regulation may be encountered. Perhaps severe reduction of body temp in cool or cold environments. More probably, febrile responses in warm environments or during exercise. 7. Progressive hypotension with death in peripheral vascular collapse, perhaps associated with acidosis due to lactic acidemia & other products of hypermetabolism. 8. In nonfatal poisonings, severe & protracted ... /SRP: neuropathy/ with pain, paresthesias & weakness. ... humans have experienced muscle fasciculations as well as myotonia. Chronic exposure may lead to central nervous system defects in the control of motor function. /2,4-D/

/SIGNS AND SYMPTOMS/ Inhalation of spray may cause burning sensations in the nasopharynx & chest, & coughing may result. Prolonged inhalation sometimes causes dizziness. /Chlorophenoxy compounds/

/SIGNS AND SYMPTOMS/ When ingested, high concentrations of chlorophenoxy compounds may irritate the mouth & throat, & GI tract. ... chest pain (from esophagitis), abdominal pain & diarrhea commonly ensue. ... absorbed chlorophenoxy compounds have caused fibrillary muscle twitching, skeletal muscle tenderness, & myotonia ... ingestion of very large amounts has produced metabolic acidosis, fever, tachycardia, hyperventilation, vasodilatation & sweating. Particular cases have been characterized by coma & convulsions. /Chlorophenoxy compounds/

/SIGNS AND SYMPTOMS/ Ingestion of large amounts of chlorophenoxy acids has resulted in severe metabolic acidosis in humans. Such cases have been associated with electrocardiographic changes, myotonia, muscle weakness, myoglobinuria, and elevated serum creatine phosphokinase, all reflecting injury to striated muscle. Because chlorophenoxy acids are weak uncouplers of oxidative phosphorylation, extraordinary doses may produce hyperthermia from increased production of body heat. /Chlorophenoxy acids/

For more Human Toxicity Excerpts (Complete) data for DICHLOROPROP (9 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ 2,4-DP technical /(PC 031401, a racemic mixture) was/ a severe to corrosive ocular irritant /in a ratbbit primary eye irritation study,/ a mild to moderate dermal irritant /in a rabbit primary skin irritation study, and a/ skin sensitizer /in a guinea pig dermal sensitization study/. /2,4-DP technical/ /From table/

/LABORATORY ANIMALS: Acute Exposure/ 2,4-DP-p technical /was/ a severe eye irritant /in a ratbbit primary eye irritation study and/ a slight or mild irritant /in a rabbit primary skin irritation study but/ not a skin sensitizer /in a guinea pig dermal sensitization study/. /2,4-DP-p technical/ /From table/

/LABORATORY ANIMALS: Acute Exposure/ Dichlorprop was/ irritating to rabbit skin and eyes in Draize tests /but/ not sensitizing to guinea pig in the maximization test and an open epicutaneous test.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ ... In 98 day feeding trials no toxic effect was observed in rats receiving 12.4 mg/kg daily, though slight liver hypertrophy occurred at 50 mg/kg daily.

For more Non-Human Toxicity Excerpts (Complete) data for DICHLOROPROP (40 total), please visit the HSDB record page.

LC50 /Lepomis macrochirus/ (Bluegill sunfish) 165 mg/L/48 hr /Conditions of bioassay not specified/ /Dichlorprop dimethylammonium salt/

LC50 /Lepomis macrochirus/ (Bluegill sunfish) 16 mg/L/48 hr /Conditions of bioassay not specified/ /Dichlorprop isooctyl ester/

LC50 Colinus virginianus (Northern bobwhite, age 14 days) diet 9907 ppm (6938-52102 ppm) for 8 days

LC50 Anas platyrhynchos (Mallard duck, age 14 days) diet >10000 ppm for 8 days

For more Ecotoxicity Values (Complete) data for DICHLOROPROP (19 total), please visit the HSDB record page.

/BIRDS AND MAMMALS/ Terrestrial animals (birds, mammals, reptiles, and terrestrial-phase amphibians) that are nesting in or near the treated field may be exposed to 2,4-DP-p due to direct deposition from labeled use of the pesticide, runoff, and from spray drift onto areas adjacent to treated sites. The greatest 2,4-DP-p residues and exposure levels are likely to occur in the surface soil and on foliage (e.g., short and tall grasses, broadleaf plants), seeds, and insects on treated areas immediately following ground spraying and/or granular treatments. In addition to exposure through spray residues on and adjacent to the application area, direct terrestrial exposure is also expected through granular applications, as animals may ingest the granules. Bioaccumulation of 2,4-DP-p in the food chain is not expected to be a significant exposure source to non-target terrestrial organisms. Residues of 2,4-DP-p from single and multiple applications are expected to occur on avian and mammalian food items. For birds, the acute risk Level of Concern (LOC) is 0.5. Based on estimated avian dose-based acute Risk Quotients (RQs) for spray applications to both turf and for brush control applications, the LOC for non-endangered birds is exceeded for some scenarios. The acute endangered RQ exceeded the LOC of 0.1 for acute risk to birds. Because the subacute dietary LC50 was non-definitive (greater than the highest test concentration 4,625 mg ae/kg), dietary based acute RQs would not exceed the LOC and, thus, were not calculated in the assessment. The dietary-based chronic RQs for birds exceed the /EPA's/ LOC of 1 for most food items, which applies to both non-endangered and endangered species. ... EPA assesses acute and chronic risk to mammals based on an acute LOC of 0.5, acute endangered LOC of 0.1, and a chronic LOC of 1.0. Mammalian acute and chronic RQs exceeded the LOCs for some food items based on both spray and granular applications at the maximum application rate of 6.0 lbs ae 2,4-DP-p/A./Dichlorprop-p/

/PLANTS/ Risk Quotients (RQs) are developed for terrestrial (dryland) plants are based on 2,4-DP-p runoff and drift from one treated hectare moving to adjacent areas, whereas semi-aquatic areas (wetlands) are based on movement from a ten-hectare site. As expected with an herbicide, the acute Levels of Concern (LOCs) (LOC of 1 for plants) were exceeded for endangered and non-endangered terrestrial and semiaquatic plants located adjacent to treated areas, both as a result of combined runoff and spray drift, and from spray drift alone for 2,4-DP-p./Dichlorprop-p/

/OTHER TERRESTRIAL SPECIES/ Not toxic to bees.

LC50 /Lepomis macrochirus/ (Bluegill sunfish) 165 mg/L/48 hr /Conditions of bioassay not specified/ /Dichlorprop dimethylammonium salt/

LC50 /Lepomis macrochirus/ (Bluegill sunfish) 16 mg/L/48 hr /Conditions of bioassay not specified/ /Dichlorprop isooctyl ester/

LC50 Colinus virginianus (Northern bobwhite, age 14 days) diet 9907 ppm (6938-52102 ppm) for 8 days

LC50 Anas platyrhynchos (Mallard duck, age 14 days) diet >10000 ppm for 8 days

For more Ecotoxicity Values (Complete) data for DICHLOROPROP (19 total), please visit the HSDB record page.

/BIRDS AND MAMMALS/ Terrestrial animals (birds, mammals, reptiles, and terrestrial-phase amphibians) that are nesting in or near the treated field may be exposed to 2,4-DP-p due to direct deposition from labeled use of the pesticide, runoff, and from spray drift onto areas adjacent to treated sites. The greatest 2,4-DP-p residues and exposure levels are likely to occur in the surface soil and on foliage (e.g., short and tall grasses, broadleaf plants), seeds, and insects on treated areas immediately following ground spraying and/or granular treatments. In addition to exposure through spray residues on and adjacent to the application area, direct terrestrial exposure is also expected through granular applications, as animals may ingest the granules. Bioaccumulation of 2,4-DP-p in the food chain is not expected to be a significant exposure source to non-target terrestrial organisms. Residues of 2,4-DP-p from single and multiple applications are expected to occur on avian and mammalian food items. For birds, the acute risk Level of Concern (LOC) is 0.5. Based on estimated avian dose-based acute Risk Quotients (RQs) for spray applications to both turf and for brush control applications, the LOC for non-endangered birds is exceeded for some scenarios. The acute endangered RQ exceeded the LOC of 0.1 for acute risk to birds. Because the subacute dietary LC50 was non-definitive (greater than the highest test concentration 4,625 mg ae/kg), dietary based acute RQs would not exceed the LOC and, thus, were not calculated in the assessment. The dietary-based chronic RQs for birds exceed the /EPA's/ LOC of 1 for most food items, which applies to both non-endangered and endangered species. ... EPA assesses acute and chronic risk to mammals based on an acute LOC of 0.5, acute endangered LOC of 0.1, and a chronic LOC of 1.0. Mammalian acute and chronic RQs exceeded the LOCs for some food items based on both spray and granular applications at the maximum application rate of 6.0 lbs ae 2,4-DP-p/A./Dichlorprop-p/

/PLANTS/ Risk Quotients (RQs) are developed for terrestrial (dryland) plants are based on 2,4-DP-p runoff and drift from one treated hectare moving to adjacent areas, whereas semi-aquatic areas (wetlands) are based on movement from a ten-hectare site. As expected with an herbicide, the acute Levels of Concern (LOCs) (LOC of 1 for plants) were exceeded for endangered and non-endangered terrestrial and semiaquatic plants located adjacent to treated areas, both as a result of combined runoff and spray drift, and from spray drift alone for 2,4-DP-p./Dichlorprop-p/

/OTHER TERRESTRIAL SPECIES/ Not toxic to bees.

The substance is very toxic to aquatic organisms. The substance may cause long-term effects in the aquatic environment. This substance does enter the environment under normal use. Great care, however, should be taken to avoid any additional release, for example through inappropriate disposal.

Dichlorprop's production may result in its release to the environment through various waste streams; its use as a herbicide will result in its direct release to the environment. If released to air, a vapor pressure of 7.5X10-8 mm Hg at 25 °C indicates dichlorprop will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase dichlorprop will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 34 hours. Particulate-phase dichlorprop will be removed from the atmosphere by wet or dry deposition. Dichlorprop contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, dichlorprop is expected to have very high to high mobility based upon Koc values of 34-129. The pKa of dichlorprop is 3.1, indicating that this compound will exist almost entirely in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil surfaces is not expected to be an important fate process because anions do not volatilize. Biodegradation of dichlorprop in soil has been measured to be from no degradation in 28 days to a half-life of 4 days. Dichlorprop has been shown to photodegrade on soil surfaces and in aquatic environments. If released into water, dichlorprop is expected to adsorb to suspended solids and sediment based upon the Koc values. Several aquatic aerobic studies have reported degradation of dichlorprop in 5 months or less. The pKa indicates that dichlorprop will exist almost entirely in the anion form at pH values of 5 to 9 and therefore, volatilization from water surfaces is not expected to be an important fate process. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to dichlorprop may occur through inhalation and dermal contact with this compound at workplaces where dichlorprop is produced or used. Monitoring data indicate that the general population may be exposed to dichlorprop via inhalation and dermal contact with this compound when using this herbicide. (SRC)

Dichlorprop's production may result in its release to the environment through various waste streams; its use as a herbicide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 34-129(2), indicate that dichlorprop is expected to have very high to high mobility in soil(SRC). The pKa of dichlorprop is 3.1(3), indicating that this compound will exist almost entirely in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization of dichlorprop from moist soil surfaces is not expected to be an important fate process because anions do not volatilize(SRC). Dichlorprop is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 7.5X10-8 mm Hg(5). Half-lives for the photodegradation of dichlorprop on dry soil ranged from 10 to 19 days(6), increasing to 22 to 59 days for these soils amended with 10% peat(9). Biodegradation half-lives in soil range from 4 days(7) to 124 days(8) and dichlorprop was shown to degrade rapidly after a lag period; the lag period decreased with repeated application and the degradation rate increased with increased pH(9).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 34-129(2) indicate that dichlorprop is expected to adsorb to suspended solids and sediment(SRC). A pKa of 3.1(3) indicates dichlorprop will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from a log Kow of 3.43(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Aqueous photodegradation rates of dichlorprop in water from the Danube River, Lake Constance, Kleine Kinzig reservoir, and the Rhine River were 3.02X10-6/sec, 1.54X10-6/sec, 2.81X10-6/sec, and 2.38X10-6/sec, respectively(13), corresponding to half-lives of approximately 3 days, 5 days, and 7 hours, respectively(SRC). Photodegradation products are 6% 2-chlorophenol, 19% 2,4-dichlorophenol, 6% 4-chlorophenol, 6% 2,4-dichlorophenyl acetate, 6% lactone of 2(4-chloro-2-hydroxyphenoxy)propionic acid and 13% 2-(2-chlorophenoxy)propionic acid(12). Several aquatic aerobic studies have reported degradation of dichlorprop in 5 months or less(9-11), indicating that biodegradation is not an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dichlorprop, which has a vapor pressure of 7.5X10-8 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase dichlorprop is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 34 hours(SRC), calculated from its rate constant of 1.1X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase dichlorprop may be removed from the air by wet or dry deposition(SRC). Dichlorprop contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight(4).

AEROBIC: Using a soil inoculum in a laboratory experiment, the time to complete disappearance under the influence of UV at 283 mu was greater than 205 days using concentrations of 50, 50, and 80 ppm dichlorprop added to 3 soils(1). Dichlorprop had half-lives of 10, 38, and 4 days in soil from Hole (sandy loam), Kroer (loam), and Froland (highly decomposed organic), Norway, respectively(2). Dichlorprop was not degraded in by soil bacterium after 28 days with a starting concn of 50 ug/mL and incubated at 30 °C(3). No degradation of dichlorprop was found after 45 days in Lanna clay(4). The half-life for the R and S isomers for dichlorprop in soil are reported as 8.7 and 4.4 days, respectively, and it degrades completely in 31 days with biological mediated degradation(5). The calculated half-lives of the R and S isomers of dichlorprop for 0-15 day incubation are 21.9 and 7.1 days, at 16-35 days incubation, 4.6 to 3.9 days, and for 52 days incubation, 6.0 and 6.8 days using garden soil at pH 7.0 and 1.6% organic carbon(6). Dichlorprop had a half-life of 5 days in soil from Vienna, Austria incubated at 21 °C for 32 days(7). Dichlorprop was shown to degrade rapidly in soil after a lag period; the lag period decreased with repeated application, and the degradation rate increased with increased pH(8). In soil, metabolism involves degradation of the side-chain to 2,4-dichlorophenol, ring hydroxylation, and subsequent ring opening(9). Dichlorprop was degraded in an aerobic aquatic study at 1.6 ug/L/day after a 31 day lag and at 2.0 ug/L/day after a 21 day lag period(10). Dichlorprop was degraded aerobically after acclimation in a sandy aquifer in 5 months(11). Dichlorprop was rapidly degraded in 14 days in an aerobic limestone aquifer after a 4 day lag period(12). Dichlorprop was microbially degraded in Danish aquifers in 124 days with a lag time of at least 62 days(13).

ANAEROBIC: No degradation of dichlorprop was observed after 140 days in an anaerobic limestone aquifer(1). Dichlorprop, isomer not specified, was not anaerobically degraded when incubated in groundwater from former industrial sites lolcated in Bornholm and Sjoelund, Denmark(2). Half-lives in groundwater at 15 °C were measured to be 1,235 and 824 days at initial concns of 1 and 5 ug/L dichlorprop, respectively, with a lag-period of several months(3). Half-lives in groundwater at 22 °C were measured to be 1,286 and 196 days at initial concns of 1 and 5 ug/L dichlorprop, respectively, with a lag-period of several months(3).

The rate constant for the vapor-phase reaction of dichlorprop with photochemically-produced hydroxyl radicals has been estimated as 1.1X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 34 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Dichlorprop is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Dichlorprop contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight(2). Photodegradation of dichlorprop in water produced 6% 2-chlorophenol, 19% 2,4-dichlorophenol, 6% 4-chlorophenol, 6% 2,4-dichlorophenyl acetate, 6% lactone of 2(4-chloro-2-hydroxyphenoxy)propionic acid and 13% 2-(2-chlorophenoxy)propionic acid(3). Photodegradation rates of dichlorprop in water from the Danube River, Lake Constance, Kleine Kinzig reservoir, and the Rhine River were 3.02X10-6/sec, 1.54X10-6/sec, 2.81X10-6/sec, and 2.38X10-6/sec, respectively(4), corresponding to half-lives of approximately 3 days, 5 days, and 7 hours, respectively(SRC). Half-lives for the photodegradation of dichlorprop on dry soil from Vega de Granada, Spain were 17, 10 and 19 days on soil 1 (30.7% sand, 61.4% silt, 7.9% clay, 2.1% organic matter), soil 2 (67.6% sand, 33.5% silt, 1.5% organic matter) and soil 3 (22% sand, 45.2% silt, 32.7% clay, 1.4% organic matter), respectively(5). When these three soils were amended with 10% peat, the photodegradation half-lives were 25, 22 and 59 days for soils 1, 2 and 3, respectively(5).

An estimated BCF of 3 was calculated in fish for dichlorprop(SRC), using a log Kow of 3.43(1) and a regression-derived equation(2). The bioconcentration factor for dichlorprop was also estimated as 23(3). According to a classification scheme(4), these BCFs suggest the potential for bioconcentration in aquatic organisms is low(SRC).

Koc values for dichlorprop were experimentally determined to be 50-62 in three soils ranging from pH 5-5.3(1). Koc values of 113 and 118 were determined in soils at respective pHs of 4.4 and 4.1(1). Koc values have also been measured as 34-129(2) and 36.6-60(3). According to a classification scheme(4), these Koc values suggest that dichlorprop is expected to have very high to high mobility in soil. The pKa of dichlorprop is 3.1(5), indicating that this compound will exist almost entirely in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(6). Dichlorprop has a pesticide leaching potential of 49 when used as a foliar applicant(7).

Koc values for dichloroprop using German and Austrian soils(1). [Table#3255]

Koc values for dichloroprop on 12 calcareous soils from the Vega de Granada, southeast Spain(1). [Table#3256]

A pKa of 3.1(1) indicates dichlorprop will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces or moist soil is not expected to be an important fate process(2). Dichlorprop is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7.5X10-8 mm Hg(3).

GROUNDWATER: In a 1969 to 1978 monitoring analysis of well water from 237 wells from agricultural areas of Ontario, Canada, dichlorprop was detected in only two wells at levels of 1.1-10 and 101-1,000 ug/L(1). Dichlorprop was detected at a concn range of 0.05-0.1 ug/L in water samples from 206 waterworks wells in various parts of the Federal Republic of Germany(2). A 1989 to 1991 survey of Denmark ground water reported dichlorprop in 4 of 80 samples with concns of 0.08-0.22 ug/L in the Hojvads Rende area and 4 of 58 samples with concns of 0.09-1.36 ug/L in the Bolbro Bock area(3). A national summary run from 1971 to 1991 of pesticides in groundwater revealed dichlorprop in 2 of 1207 wells tested at concns of 0.09 to 0.400 ug/L(4). Spring water tested at 16 sites in Canada from 1991 to 1994 found 2 samples contained dichlorprop at concns of 0.6 ng/L from the North Tile drain in Outlook and 1.0 ng/L at Antelope Lake, Saskatchewan(5). Dichlorprop was not detected in surface water samples taken at golf courses across the United States(6). Dichlorprop was not detected (detection limit 0.01 ug/L) in samples from 45 sites in 12 midwest states in 1992(7). Dichlorprop was detected in 0.09% of 2306 samples taken 1992 to 1996 from 20 units of the National Water Quality Assessment Program(8). Danish groundwater survey gave dichlorprop concns of <0.1 ug/L in 5 of 32 samples from Hojvads Rende, 1 of 35 samples from Lille Baek, 1 of 53 samples from Odder Baek and was not detected in 184 samples from Bolbro Baek(9).

DRINKING WATER: Dichlorprop was not detected in 783 rural and 566 community drinking water wells in a US national pesticide survey(1). Dichlorprop was not detected, detection limit 2.5 ug/L, in 53 residential drinking water wells in CT(2).

SURFACE WATER: Dichlorprop was not detected in surface water samples taken at golf courses across the United States(1). Dichlorprop was detected in 3.9% of 78 samples taken Jan to Dec 1993 at four sites (Orestimba Creek, Merced River, Salt Slough and San Joaquin River) in the San Joaquin River basin, US at a maximum of 0.11 ug/L(2). Dichlorprop was detected in 1% of samples taken in 8 US urban streams at a maximum concn of 0.19 ug/L; positive samples were found in Norwalk River, Winnipauk, CT and Annandale, VA(3).

SURFACE WATER: Between 1971-77, dichlorprop was detected at maximum concns of 0.007-7.15 ug/L in surface water from 11 water quality districts in Western Canada(1). Dichlorprop was qualitatively detected in the Trent and Saugeen Rivers, aquatic systems in the Lake Ontario and Huron water basins, respectively(2). During a Jan 1981 to Dec 1985 water monitoring analysis of the mouths of Grand, Saugeen and Thames River (Ontario, Canada), dichlorprop was detected at concns of the 1 ug/L magnitude in 1 of 96 Grand River samples, 1 of 143 Saugeen River samples, and 16 of 222 Thames River samples(3). Dichlorprop was measured in surface water from Tobacco Creek in Manitoba, Canada at concns of <0.01-20 ng/L from the summer of 1993 to the spring of 1996(4). Dichlorprop was found in, location (% of samples, median concn ng/L); Assiniboine River (39% of 32, <0.007), LaSalle River (48% of 32, 0.092), Morris River (63% of 31, 0.56), Pembine River (44% of 31, <0.007), Rat River (38% of 32, <0.007), Roseau River (16% of 32, <0.007), Sein River (50% of 32, 0.06), Red River at Emerson (32% of 31, <0.007), Red River at Ste Agathe (31% of 32, <0.007), and Red River at Selkirk (52% of 33, 0.06) surveyed 1993-1995 in southern Manitoba, Canada(5). Dichlorprop was found in 90% of samples taken in 10 wetlands after torrential rain storms (390-465 mm of rain from May 20 to July 3, 2000) in Neville, Canada(6). Dichlorprop was found in 100% of samples taken one year later following drought conditions (62 mm of rain May 20 to July 5, 2001) in 5 of the previously sampled wetlands(6). Dichlorprop was detected in 86%, 79%, 80%, and 90% of surface water samples taken June 17, 1996 to July 8, 1998 in a wildlife area with no pesticide use (0.019 ug/L), farms with no pesticide use (0.036 ug/L), farms with tilling (0.022 ug/L), and farms with minimal tilling (0.050 ug/L), respectively, Saskatchewan, Canada(7).

For more Environmental Water Concentrations (Complete) data for DICHLOROPROP (6 total), please visit the HSDB record page.

Dichlorprop was detected in landfill leachate from a site in New Jersey at respective average concns of 5 and 1 ug/L in 1989 and 1990(1). Dichlorprop was detected in 1990 in landfill leachate from a site in Oregon at an average concn of 2 ug/L(1). Dichlorprop was also found at concn of 2 ug/L in 1989 and 3 ug/L in 1990 in landfill leachate from a site in Wisconsin(1). Dichlorprop was found in runoff water 15 minutes after runoff started at about 0.30 ug/L(2). Dichlorprop was applied to field of winter barley in Scheyern, Bavaria and a runoff concn of 7.8% of the 1.2 kg/ha application was found one day after application(3). Dichlorprop was applied to field of summer barley in Freising, Bavaria and a runoff concn of 1.4% of the 1.2 kg/ha application was found one day after application(3). Dichlorprop was found at a maximum concn of 20 ug/L May to Sept 1990 in an agricultural catchment basin in Vemmenhog, Sweden(4). In a review of accidents and incidents 0.5 ton of dichlorprop was released to a river, river location and date were not given(5). Dichlorprop was found in landfill leachate at concns of 0.01-750 and 0.031-9.8 ug/L in 20 of 34 samples from Bornholm and 17 of 30 samples from Sjoelund, Denmark, respectively(6). Dichlorprop was present in runoff water at 0.02% of applied concn after 30 mm of rainfall(7). Dichlorprop was found in agrochemical sewage in the UK at 18 ug/L and in secondary effluent at 0.1 ug/L(8).

SEDIMENT: Dichlorprop was detected at 2 ug/kg in mobile sediment June to July 1990, and at 2 ug/kg June 18, 1991 in pond sediment at the south part of a pond, and at <2 ug/kg in the north part of the pond and at a stream 200 m south of a culvert outlet in southern Sweden(1).

RURAL/REMOTE: Dichlorprop was found in the particulate phase at 39, 17, 15, and 6 pg/cu m on June 21, 1993, Oct 11, 1994, June 26, 1995, and June 24, 1996, respectively, from a prairie in Manitoba, Canada(1). Dichlorprop was found in the vapor phase at 300, 160, and 930 pg/cu m on June 19, 1994, Aug 7, 1995, and June 28, 1996, respectively, from the same area(1). Dichlorprop was not detected (detection limit 0.2 pg/cu m) in 1993 in a recreation area near Larimore, ND and in 1994 on the western edge of the University of North Dakota(2). Dichlorprop was detected in 15 of 634 samples (222 precipitation, 124 dry deposition, 288 air), positive samples were not identified, taken in Johnson County, IA Oct 1996 to Sept 1997(3).

Dichlorprop was not identified at a concentration above 0.01 mg/kg between 1980 and 1984 in 179 fruit composites Ontario, Canada(1). Dichlorprop was not found at a concentration above 0.01 mg/kg in 354 vegetable composites from Ontario, Canada between 1980 and 1985(2).

A 1989 to 1991 survey of Denmark runoff water reported dichlorprop in 4 of 42 samples with concentrations of 0.04-0.12 ug/L in the Hojvads Rende area(1). Both the R and S isomers of dichlorprop were found in 1 sample from the runoff of a tile roof in Tuffenwies industrial area in northwest Zurich, Switzerland in July 1995(2). Dichlorprop runoff concentrations were sampled Oct 1991 to Sept 1993 in Ransoelille, Denmark on the banks of Langvad Stream; concentrations were below detection limit from Oct 1, 1991 through May 12 1992, detected May 12 through Nov 10, 1992 with a maximum of 4.64 ug/L in Aug, and occasionally detected through the end of the study with a maximum concentration of 0.39 ug/L(3).

Occupational exposure to dichlorprop may occur through inhalation and dermal contact with this compound at workplaces where dichlorprop is produced or used(SRC). During spray operations in 1980 along an electric power transmission line right-of-way, workers of two different sprayers were exposed to average concns of 9.2 and 17.2 ug/cu m dichlorprop in breathing zone air(1). Monitoring data indicate that the general population may be exposed to dichlorprop via inhalation and dermal contact with this compound when using this herbicide(SRC).

Average concentrations of 1.27 and 3.67 were detected in the urine of workers of a roadside sprayer and a right-of-way sprayer, respectively, exposed to dichlorprop during spray operations in 1980 along an electric power transmission line right-of-way(1). Median urine concentrations of dichlorprop were 0.23 and 0.74 ug/mL in 16 farmers and 6 spraymen exposed to dichlorprop(2).

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Do not transport with food and feedstuffs. Marine pollutant.

Symbol: Xn; R: 21/22-38-41; S: (2)-26-36/37

UN Hazard Class: 9; UN Pack Group: III