|
|
Consumer Factsheet on: 1,2,4-TRICHLOROBENZENE
List of Contaminants
As part of the Drinking Water and Health pages, this fact
sheet is part of a larger publication:
National Primary Drinking Water Regulations
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).
What is 1,2,4-TCB and how is it used?
1,2,4-Trichlorobenzene (1,2,4-TCB) is an aromatic, colorless
organic liquid. The greatest use of 1,2,4-trichlorobenzene is
primarily as a dye carrier. It is also used to make herbicides and
other organic chemicals; as a solvent; in wood preservatives; in
abrasives. It was once used as a soil treatment for termite
control.
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:
Hostetex L-PEC
Trichlorobenzol
Why is 1,2,4-TCB 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 Goals.
The MCLG for 1,2,4-trichlorobenzene has been set at 0.07 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 also been set at 0.07 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 1,2,4-trichlorobenzene to potentially
cause the following health effects when people are exposed to it at
levels above the MCL for relatively short periods of time: changes
in liver, kidneys and adrenal glands
Long-term: 1,2,4-Trichlorobenzene has the potential to cause the
following effects from a lifetime exposure at levels above the MCL:
increased adrenal gland weights
How much 1,2,4-TCB is produced and released to the environment?
Current production figures on 1,2,4-trichlorobenzene are not
available. EPA estimated 1983 production to be in the range of 3 to
8 million lbs., with imports over 3 million lbs. Major
environmental releases of 1,2,4-trichlorobenzene are due to its
manufacture and use as a dye carrier.
From 1987 to 1993, according to EPA's Toxic Chemical Release
Inventory, 1,2,4-trichlorobenzene releases to land and water
totalled over 180,000 lbs. These releases were primarily from
textile finishing industries. The largest releases occurred in
North Carolina and Virginia.
What happens to 1,2,4-TCB when it is released to the environment?
1,2,4-Trichlorobenzene (1,2,4-TCB) binds well to the soil and
therefore will not leach appreciably to the groundwater when
released to land. However, 1,2,4-TCB has been detected in some
groundwater samples which indicates that it can be transported
there by some process. If released to water it will largely
evaporate within a few hours. It has some potential to accumulate
in fish.
How will 1,2,4-TCB be Detected in and Removed from My Drinking
Water?
The regulation for 1,2,4-trichlorobenzene became effective in 1994.
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 1,2,4-trichlorobenzene 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
1,2,4-trichlorobenzene so that it is consistently below that level.
The following treatment methods have been approved by EPA for
removing 1,2,4-trichlorobenzene: Granular activated charcoal in
combination with Packed Tower Aeration.
How will I know if 1,2,4-TCB is in my drinking water?
If the levels of 1,2,4-trichlorobenzene exceed the MCL, 0.07 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.
Drinking Water Standards:
Mclg: 0.07 ppm
Mcl: 0.07 ppm
1,2,4-TCB Releases to Water and Land, 1987 to 1993 (in pounds):
| Water | Land |
TOTALS (in pounds) | 157,541 | 22,835 |
Top Five States* |
---|
NC | 80,253 | 13,209
|
VA | 36,970 | 0
|
GA | 17,639 | 8,951
|
WV | 20,300 | 0
|
NY | 1,150 | 1
|
Major Industries* |
---|
Finishing plants, misc | 52,249 | 0
|
Finishing plants, synth. | 47,976 | 0
|
Weaving, finishing mills | 20,139 | 8,951
|
Alkalies, chlorine | 21,773 | 1
|
Knitting mills, misc | 9,077 | 9,994
|
Knit outerwear mills | 1,300 | 3,200
|
* Water/Land totals only include facilities with releases greater
than 100 lbs.
Learn more about your drinking water!
EPA strongly encourages people to learn more about their drinking
water, and to support local efforts to protect and upgrade the
supply of safe drinking water. Your water bill or telephone books
government listings are a good starting point.
Your local water supplier can give you a list of the chemicals they
test for in your water, as well as how your water is treated.
Your state Department of Health/Environment is also a valuable
source of information.
For help in locating these agencies or for information on drinking
water in general, call: EPAs Safe Drinking Water Hotline: (800)
426-4791.
For additional information on the uses and releases of chemicals in
your state, contact the: Community Right-to-Know Hotline: (800) 424-9346.
List of Contaminants
|