United States Office of Water EPA 811-F-95-003 j-T
Environmental Protection 4601 October 1995
Agency
vvEPA National Primary Drinking
Water Regulations
Dibromochloropropane
CHEMICAL/PHYSICAL PROPERTIES OCTANOL/WATER PARTITION (Kow): BIOCONCENTRATION FACTOR: 11 (est.);
Log Kow = 2.43 (calculated) low bioconcentration potential
CAS NUMBER: 96-12-8
SOLUBILITY: 1.23 g/L of water at 25° C; HENRY'S LAW COEFFICIENT:
COLOR/ FORM/ODOR: Slightly soluble in water 1.47x10"4 atm-cu m/mole;
Dense yellow liquid with pungent odor;
MAY ALSO BE GRANULAR **OIL SORPTION COEFFICIENT: TRADE NAMES/SYNONYMS: DBCP;
Log Koc = 2.01; high mobility BBC 12; Fumagon; Fumazone;
M.P.: 5° C B.P.: 196° C ' Nemabrom; Nemafum; Nemagon;
ODOR/TASTE THRESHOLDS: Taste Nemanax; Nemapaz; Nemaset;
VAPOR PRESSURE: 0.8 mm Hg at 21 C threshold in water is 0.01 mg/L Nemazon; Gro-Tone Nematode;
DENSITY/SPEC. GRAV.: 2.08 at 20° C Durham Nematocide EM 17.1
DRINKING WATER STANDARDS Though it is also used as a chemical intermediate in the
MCLG- zero mg/L - production of a flame-retardant, essentially all of its
present use is as a soil fumigant.
Mcu: 0.0002 mg/L
HAL(child): 1 day: 0.2 mg/L RELEASE PATTERNS
10-day: 0.05 mg/L ]n the past re|ease of DBCP to the environment
occurred primarily from its fumigant and nematocide
HEALTH EFFECTS SUMMARY uses. In 1977,831,000 pounds of DBCP was used in CA
Acute: EPA has found DBCP to potentially cause alone, mainly on grapes and tomatoes. In 1974, USA
kidney and liver damage and atrophy of the testes. farmers applied 9.8 million pounds of DBCP on crops.
Drinking water levels which are considered "safe" for All registrations of end use products were cancelled in
short-term exposures: For a 10-kg (22 Ib.) child consum- 1979 except for the use as a soil fumigant against
ing 1 liter of water per day, a one-day exposure of 0.2 mg/ nematodes on pineapples in Hawaii. This use was can-
L or a ten-day exposure to 0.05 mg/L. celled in 1985. The use of DBCP as a laboratory reactant
Chronic: DBCP has the potential to cause kidney is not expected to result in significant release to the
damage and antifertility effects from long-term exposure environment.
at levels above the MCL.
Cancer: There is some evidence that DBCP may have ENVIRONMENTAL FATE
the potential to cause cancer from a lifetime exposure at DBCP released to soil will likely volatilize or leach to
levels above the MCL. * groundwater. In a model soil assumed to contain 1,2-
dibromo-3-chloropropane (DBCP) evenly distributed
USAGE PATTERNS within the first 10 cm, the volatilization half-life of DBCP
was estimated to be 1.2 days. The observed log soil
DBCP was once used as an unclassified nematocide sorptjon coefficjent (Koc) of DBCP is 2.11 in an unspeci-
for soil fumigation of cucumbers, summer squash, cab- fied soj, ,n a soj, contajning 10% moisture, the log Koc of
bage, cauliflower, carrots, snap beans, okra, aster, shasta DBCP is 1.6. Modelling predicted that DBCP will adsorb
aisy, ornamental turf (lawns), bermudagrass, so weak)y that jt wj,| co.mjgrate with water through low
centipedegrass, St Augustine grass, zoysia grass, ardisia, organjc content soil.
azalea, camellia, forsythia, gardenia, hibiscus, roses,
and arborvitae ln alkaline soils, hydrolysis may be significant and
: biodegradation is possible but is expected to be slow
October 1995 Technical Version Printed on Recycled Paper
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relative to volatilization and leaching to groundwater. Soil
microorganisms (primarily Pseudomonas and
Flavobacteria) dehalogenated DBCP at a rate of 20% in
1 week at pH 8.
In water, DBCP is expected to volatilize rapidly and
hydrolyze slowly. Using measured values of the water
solubility and vapor pressure of 1230 mg/l and 0.58 mm
Hg, respectively, a Henry's Law constant of 1.47X10"*
atm-cu m/mol was estimated. The volatilization half-life
values were 9.5 hr, 13.5 hr, and 224.2 days, respectively,
for streams, rivers, and lakes.
Hydrolysis half-lives of 38 and 141 years have been
reported at 25 and 15 deg C, respectively, at pH 7. In
groundwater, DBCP is expected to persist due to its low
estimated rate of hydrolysis (half-life= 141 years at 15
deg C). Biodegradation may occur, but is expected to be
slow relative to the rate of volatilization. Sorption to
sediments and bioconcentration are not expected to be
significant fate processes.
In the atmosphere, vapor phase DBCP is expected to
react with photochemically produced hydroxyl radicals
with an estimated half-life of 12.19 days.
A bioconcentration factor for 1,2-dibromo-3-
chloropropane of 11 was estimated from a measured
water solubility of 1,230 ppm.
October 1995
Technics
OTHER REGULATORY INFORMATION
MONITORING:
FOR GROUND/SURFACE WATER SOURCES:
INITIAL FREQUENCY- 4 quarterly samples every 3 years
REPEAT FREQUENCY- If no detections during initial round:
2 quarterly per year if serving >3300 persons; '
1 sample per 3 years for smaller systems
TRIGGERS - Return to Initial Freq. if detect at > 0.00002 mg/L
ANALYSIS:
REFERENCE SOURCE METHOD NUMBERS
EPA 600/4-88-039 504.1; 551
TREATMENT:
BEST AVAILABLE TECHNOLOGIES
Granular Activated Charcoal
FOR ADDITIONAL INFORMATION:
* EPA can provide further regulatory and other general information:
EPA Safe Drinking Water Hotline - 800/426-4791
4 Other sources of lexicological and environmental fate data include:
Toxic Substance Control Act Information Line - 202/554-1404
Toxics Release Inventory, National Library of Medicine - 301/496-6531
Agency for Toxic Substances and Disease Registry - 404/639-6000
National Pesticide Hotline - 800/858-7378
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