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 Chlorobenzene and how is it used?
Chlorobenzene is a colorless organic liquid with a faint, almond-like
odor. The greatest use of chlorobenzene is in the manufacture of other
organic chemicals, dyestuffs and insecticides. It is also a solvent for
adhesives, drugs, rubber, paints and dry-cleaning, and as a
fiber-swelling agent in textile processing.
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:
IP Carrier T 40
Why is Chlorobenzene 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 chlorobenzene has been set at 0.1 parts per million (ppm)
because EPA believes this level of protection would not cause any of the
potential health problems described below.
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 technologies.
The MCL has been set at 0.1 ppm 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 chlorobenzene to potentially cause the following
health effects when people are exposed to it at levels above the MCL for
relatively short periods of time: anesthetic effects and impaired liver
and kidney function.
Long-term: Chlorobenzene has the potential to cause the following
effects from a lifetime exposure at levels above the MCL: liver, kidney
and central nervous system damage.
How much Chlorobenzene is produced and released to the environment?
Production of chlorobenzene in 1988 was 270 million pounds, and was
expected to decrease. Major environmental releases of chlorobenzene are
due to its use as a solvent in pesticides.
From 1987 to 1993, according to EPA's Toxic Chemical Release
Inventory, chlorobenzene releases to water totalled over 326,000 lbs.
Releases to land totalled nearly 37,000 lbs. These releases were
primarily from alkali and chlorine industries which use chlorobenzene in
chlorination processes. Most of these releases occurred in West
What happens to Chlorobenzene when it is released to the environment?
Releases into water and onto land will either evaporate or be slowly
degraded by microbes in the soil or water. Since it does not bind to
soils, it can be expected to leach into the groundwater. Little
accumulation is expected in fish and food products.
How will Chlorobenzene be detected in and removed from my drinking water?
The regulation for chlorobenzene became effective in 1989. 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
chlorobenzene is present above 0.5 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
chlorobenzene so that it is consistently below that level. The following
treatment methods have been approved by EPA for removing chlorobenzene:
Granular activated charcoal in combination with Packed Tower Aeration.
How will I know if Chlorobenzene is in my drinking water?
If the levels of chlorobenzene exceed the MCL, 0.1 ppm, 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:
|Mclg: 0.1 ppm (parts per million)
Mcl: 0.1 ppm
Chlorobenzene Releases to Water and Land, 1987 to 1993 (in pounds):
|TOTALS (in pounds)
Top Five States*|
Cyclic crudes, dyes
Gum, wood chems
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water
* Water/Land totals only include facilities with releases greater
than a certain amount - usually 1000 to 10,000 lbs.