This is a fact sheet about a chemical that may be found in some public or
private drinking water supplies. It may cause health problems if found
in amounts greater than the health standard set by the United States
Environmental Protection Agency (EPA).
What is Dibromochloropropane and how is it used?
Dibromochloropropane, or DBCP is a dense yellow organic liquid with a
pungent odor. It is used primarily as an unclassified nematocide for
soil fumigation of cucumbers, summer squash, cabbage, cauliflower,
carrots, snap beans, okra, aster, shasta daisy, lawn grasses and
The list of trade names given below may help you find out whether you
are using this chemical at home or work.
Trade Names and Synonyms:
Why is Dibromochloropropane being regulated?
In 1974, Congress passed the Safe Drinking Water Act. This law requires
EPA to determine safe levels of chemicals in drinking water which do or
may cause health problems. These non-enforceable levels, based solely on
possible health risks and exposure, are called Maximum Contaminant Level
The MCLG for DBCP has been set at zero because EPA believes this
level of protection would not cause any of the potential health problems
Based on this MCLG, EPA has set an enforceable
standard called a Maximum Contaminant Level (MCL). MCLs are set as close
to the MCLGs as possible, considering the ability of public water
systems to detect and remove contaminants using suitable treatment
The MCL has been set at 0.2 ppb because EPA believes, given
present technology and resources, this is the lowest level to which
water systems can reasonably be required to remove this contaminant
should it occur in drinking water.
These drinking water standards and the regulations for ensuring
these standards are met, are called National Primary Drinking Water
Regulations. All public water supplies must abide by these regulations.
What are the health effects?
Short-term: EPA has found DBCP to potentially cause the following health
effects when people are exposed to it at levels above the MCL for
relatively short periods of time: kidney and liver damage and atrophy of
Long-term: DBCP has the potential to cause the following effects
from a lifetime exposure at levels above the MCL: kidney damage and
How much Dibromochloropropane is produced and released to the
In the past, release of DBCP to the environment occurred primarily from
its fumigant and nematocide uses. In 1977, 831,000 pounds of DBCP was
used in CA alone, mainly on grapes and tomatoes. In 1974, USA farmers
applied 9.8 million pounds of DBCP on crops. All registrations of end
use products were canceled in 1979 except for the use as a soil fumigant
against nematodes on pineapples in Hawaii. This use was canceled in
What happens to Dibromochloropropane when it is released to the
DBCP released to soil will most likely evaporate or leach to groundwater.
Break down by microbes is slow by comparison. Once in the atmosphere,
DBCP is expected to be broken down fairly quickly by sunlight. DBCP is
not likely to accumulate in aquatic life.
How will Dibromochloropropane be detected in and removed from my
The regulation for DBCP became effective in 1992. Between 1993 and 1995,
EPA required your water supplier to collect water samples every 3 months
for one year and analyze them to find out if DBCP is present above 0.02
ppb. If it is present above this level, the system must continue to
monitor this contaminant.
If contaminant levels are found to be consistently above the MCL,
your water supplier must take steps to reduce the amount of DBCP so that
it is consistently below that level. The following treatment methods
have been approved by EPA for removing DBCP: Granular activated charcoal
together with Packed Tower Aeration.
How will I know if Dibromochloropropane is in my drinking water?
If the levels of DBCP exceed the MCL, 0.2 ppb, the system must notify the
public via newspapers, radio, TV and other means. Additional actions,
such as providing alternative drinking water supplies, may be required
to prevent serious risks to public health.
This is a factsheet about a chemical that may be found in some
public or private drinking water supplies. It may cause health problems
if found in amounts greater than the health standard set by the United
States Environmental Protection Agency (EPA).
Drinking Water Standards:
Mcl: 0.2 ppb (parts per million)
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water