1
Ethephon
Ethephon
Charge
to
the
HSRB
Charge
to
the
HSRB
Ethephon
is
an
organophosphorus
compound
that,

upon
absorption
into
plants,
forms
ethylene
gas
which
is
an
important
component
of
the
plant
hormone
complex.
The
Agency
is
conducting
an
aggregate
(
single
chemical,
multi­
route)
risk
assessment
of
ethephon.
2
Ethephon
Ethephon
Charge
to
the
HSRB
Charge
to
the
HSRB
1.
Scientific
considerations:

The
Agency's
WOE
document
and
DERs
for
ethephon
describe
the
study
design
and
results
of
the
ethephon
repeat
dose,
oral,
human
toxicity
studies.
The
WOE
document
also
discusses
the
Agency's
conclusions
regarding
the
usefulness
of
the
human
studies
in
the
aggregate,
single
chemical
risk
assessment.
The
Agency
has
concluded
that
the
28­
day
human
study
is
sufficiently
robust
to
establish
a
point
of
departure
for
extrapolating
acute
and
chronic
dietary
risk.

Please
comment
on
the
scientific
evidence
that
supports
this
conclusion.
3
Ethephon
Ethephon
Charge
to
the
HSRB
Charge
to
the
HSRB
2.
Ethical
considerations:

In
its
ethics
review
of
this
research,
EPA
documented
that
the
study
reports
contained
very
little
information
concerning
the
ethical
conduct
of
the
research
and
that
the
available
information
raised
no
ethical
concerns.
The
Agency
asks
that
the
Board
provide
comment
on
the
following,

taking
into
account
all
that
is
known
about
the
ethical
conduct
of
each
study:
4
Ethephon
Ethephon
Charge
to
the
HSRB
Charge
to
the
HSRB
2.
Ethical
considerations,
cont'd:


OPP's
conclusion
that
there
is
not
clear
and
convincing
evidence
that
the
conduct
of
the
research
was
fundamentally
unethical;
and

whether
there
is
clear
and
convincing
evidence
that
the
conduct
of
the
study
was
significantly
deficient
relative
to
the
ethical
standards
prevailing
when
the
study
was
conducted.
