»United States
                   'Environmental Protection
                    Agency
                             Office of Water
                             4601
    EPA 811-F-95-OO3dd-C
          October 1995
   £EPA       National  Primary  Drinking
                    Water Regulations
                    2,4,5 - TP (Silvex)
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
2,4,5-TP
AND HOW IS IT USED?
DRINKING WATER
STANDARDS:
MCLG:
MCL:
0.0& PPM
0.05 PPM
  2,4,5-TP is a white organic powder with little odor. Its use has been banned.
since 1985. The greatest use of 2,4,5-TP was as a postemergence herbicide for
control of woody plants, and broadleaf herbaceous weeds in rice and bluegrass
turf, in sugarcane, in rangeland improvement programs, on lawns. Aquatic uses
included control of weeds in ditches and riverbanks, on floodways, along canals,
reservoirs, streams, and along southern waterways.
  The list of trade names given below may help you find out whether you are using
this chemical at home or work.
WHYIS 2,4,5-TP
BEING REGULATED?
WHATAte THE
HEALTH EFFECTS?
  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 2,4,5-TP has been set at 0.05 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). MGLs are set  as close to the MCLGs as possible,
considering the ability of public water systems to detectand remove contaminants
Using suitable treatment technologies.
  The MCL has been set at 0.05 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 ensur-
ing these standards are met, are called National Primary Drinking
Water Regulations. All public water supplies must abide by these
regulations.
  Short-term: EPA has found 2,4,5-TP to potentially cause the
following health effects when people are exposed to it at levels
above the MCL for relatively short periods of time:  depression
and other nervous system effects, weakness, stomach irritation
        TRADE NAMES AND
        SYNONYMS:
         WEED-B-GON
         PROPON
         SILVI-RHAP
         STA-FAST
         MILLER Nu SET
         AQUA-VEX
         COLOR-SET
         DEO-WEED
         FENOPROP
         FENORMONE •
         FRUITONE T
         GARLON
         KURAN
         KUROSAL G/SL
         SILVEX
October 1995
              Consumer Version
Printed on Recycled Paper

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and minor damage to liver and kidneys.
Long-term : 2,4,5-TP has the potential to cause the following effects from a
lifetime exposure at levels above the MCL: minor liver and kidney damage.
In 1982, ,4,5-TP production was 500,’OOO pounds. Former releases were from
spraying on rangelands, runoff from fields, and direct release to water for control
of aquatic weeds.
2,4,5-TP will strongly bind to soils and is degraded by microbes, so it isn’t likely
to leach to ground water. If released to water, 2,4,5-TP will bind to sediment,
where microbes will slowly degrade it. It has a very low potential for accumulating
in aquatic life.
The regulation for 2,4,5-TP 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 2,4,5-TP is pres nt above 0.2 ppb. If it is
present above this level, the system must continue t ’. 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 2,4,5-TP so that it is consistently
below that level. The following treatment methods have been approved by EPA
for removing 2,4,5-TP: Granular activated charcoal.
If the levels of 2,4,5-TP exceed the MCL, 0.05 ppm, the system must notify the
public via newspapers, radio, 1V and other means. Additional actions, such as
providing alternative drinking water supplies, may be required to prevent serious
risks to public health..
How MUCH 2,4,5-TP
IS PRODUCED AND
RELEASED TO THE
ENVIRONMENT?
WHATHAPPENS TO
2,4,5-TP
WHEN IT IS RELEASED TOk
THE ENVIRONMENT?
HOW WILL
2,4,5-TP
BE DETECTED IN AND
REMOVED FROM
MYDPJNVJNG WATER?
How t wi.i. I , ow IF
2,4,5-TP IS IN MY
DRINKING WATER?
Learn more about your drinking water!
EPA strongly encourages people to learn more Your state Department of Health/Environment is also a
about their drinking water, and to support local efforts valuable source of information.
to protect and upgrade the supply of safe drinking For help in locating these agencies or for information on
water. Your water bill or telephone book’s govern- drinking water in general, call:
ment listings are a good starting point. EPA’s Safe Drinking Water Hotline: (800) 426-4791.
Your local water supplier can give youa list,of the For additional information on the uses and releases of
chemicals they tesi tor in your water, as well as how chemicals in your state, contact the:
your water is treated. . Community Right-to-Know Hotline: (800) 535-0202.
October 1995
Consumer Version
Page 2

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