1
Remaining
Chemicals
Overview
Ray
Kent,
Ph.
D.

Ray
Kent,
Ph.
D.

U.
S.
EPA
U.
S.
EPA
Office
of
Pesticide
Programs
Office
of
Pesticide
Programs
April
4,
2006
April
4,
2006
2
Not
all
pesticides
inhibit
cholinesterase
Not
all
pesticides
inhibit
cholinesterase

Ethephon
 
an
organophosphonate
plant
growth
regulator

Sodium
cyanide
 
post
harvest
fumigation
of
citrus

Amitraz
­
insecticide/
acaricide
with
food
&
feed
uses
3
Ethephon
Issues
for
the
HSRB
Ethephon
Issues
for
the
HSRB

Human
studies
for
ethephon
suggest
humans
are
more
sensitive
than
animals

Endpoint
in
humans
based
on
cholinergic­
like
clinical
signs

Is
the
human
endpoint
and
PoD
too
protective?
4
Cyanide
Issues
for
the
HSRB
Cyanide
Issues
for
the
HSRB

Focus
of
the
risk
assessment
is
on
acute
toxicity
rather
than
chronic
effects

Amygdalin
(
laetrile)
as
a
surrogate
for
cyanide

Whether
the
amygdalin
clinical
trial
as
conducted
provides
an
estimate
of
cyanide
acute
toxicity
5
Amitraz
Issues
for
the
HSRB
Amitraz
Issues
for
the
HSRB

Humans
appear
to
be
the
most
sensitive
species

Combining
human
toxicity
&

metabolism
studies
to
determine
an
acute
PoD

Use
of
human
studies
to
assess
scenarios
of
all
durations.
