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Atrazine - Proposed Label Changes Accepted or Revised by EPA 4/92


Most of the atrazine label changes proposed by Ciba-Geigy Corporation
have been accepted by EPA.

One of the registrant's proposed changes would require the following
label statement:

'This product may not be applied aerially or by ground within 200
feet around natural or impounded lakes and reservoirs.'

Jack Housenger, Acting Chief, Special Review Branch, Special Review and
Reregistration Division (SRRD), OPP, EPA, commented last week that this 200,
foot buffer would probably reduce but not prevent contamination.  'We do not
know whether the buffer will keep levels below the MCL (maximum contaminant
level),' he said.

'There are a lot of atrazine detections and 'you would expect to see a
lot when 80 million-90 million pounds are applied a year,' he said.

Housenger said he was not sure whether the surface water contamination
problem could be controlled nationally.  The atrazine/groundwater problem will
ultimately be dealt with by state and local governments because every instance
is different, he said.

It is possible that all triazines will be put into special review, the
EPA official said noting that the same tumor type was linked to all of them.

In an April 3 letter from Daniel Barolo, SRRD Director, EPA accepted the
registrant's proposed application rate reductions, use deletions and the 66-
foot set-backs for streams and rivers.  The set-back label language:

'This product may not be applied aerially or by ground within 66
feet of the points where field surface water runoff enters perennial or
intermittent streams or rivers.  'If this product is applied to highly
erodible land, the 66-foot buffer or set-back from runoff entry points must be
planted to crop, seeded with grass or other suitable cover crop.'

In an April 6 note to Ciba-Geigy, EPA accepted the following language
for mixing and loading:

'This product may not be mixed or loaded within 50 feet of
intermittent streams, rivers, reservoirs, impounded or natural lakes, or
within 50 feet of all wells including abandoned wells, drainage wells and sink

This note stated that the agency was 'reviewing Ciba-Geigy's request for
a waiver of the proposed 50 feet storage set-back requirement where there are
'appropriate environmental safeguards.'  In the interim, the agency has
requested that the following storage guidance remain on the label:

'Groundwater contamination may be reduced by diking and flooring
of permanent liquid bulk storage sites with an impermeable material.'

Barolo's April 3 letter to Ciba-Geigy's Richard L. Feulner, Director,
Regulatory Affairs, revised the registrant's proposed statement about
state/local requirements to read:

'Where there are state/local requirements regarding atrazine use
(including lower maximum application rates and/or set-backs) which are
different from the label, the more restrictive/protective requirements must be

The Division Director's letter stated further:

'The agency does not accept your proposal to allow applications of
atrazine when corn or sorghum is 18 inches in height (currently,
labels allow applications when crops are 12 inches).  Since the proposed
change would allow application later in the growing season, closer
to the time of harvest, this may result in increased residue levels.

'Any change in atrazine application that may increase residues on food
or feed requires formal review by OPP Residue Chemistry Branch.  This review
could not occur in time for this season's use (BASF's preference) and would
delay imposition of the surface water mitigation measures.  If you and/or BASF
wish to pursue this issue, you must submit your request to OPP Registration
Division for formal review.



     EPA has accepted a voluntary proposal by Ciba-Geigy Corp. of Greensboro,
N.C., to make a number of label restrictions to atrazine products and to carry
out additional water monitoring and educational initiatives on this pesticide.
The actions were taken by Ciba-Geigy to reduce surface water contamination by
atrazine, particularly in waters used for drinking.  Atrazine is classified as
a possible human carcinogen based on animal studies.  It is used to control
weeds, primarily on corn and sorghum and is one of the most widely used
pesticides in the United States.  Approximately 80-90 million pounds are
applied annually.  According to surveys by the U.S. Geological Survey and
others, atrazine is the most widely detected pesticide in water monitoring
studies in the Midwest corn belt.  While EPA believes that the atrazine label
restrictions will reduce water surface contamination, the Agency recognizes
that some states may have to impose additional water quality protection
measures in areas that are particularly vulnerable to runoff.  The label
changes will be in place for the 1993 crop season.  Some of the more pertinent
label restrictions are the following:  deletion of some non-crop uses
including rights-of-way, highways and railroads; reduction in the application
rates for corn and sorghum from three pounds per acre to a range of 1.6 to
2.5; an application set-back of 200 feet around all natural or impounded
waters (reservoirs and lakes) and a set-back of 66 feet from the pints where
field runoff water enters perennial or intermittent streams and rivers (on
highly credible land, the 66-foot set-back must be vegetated); and all mixing
and loading operations must have a 50 foot set-back from intermittent streams,
rivers, reservoirs, impounded and natural lakes and all wells including
drainage wells, abandoned wells and sink holes.