Status and Future Directions of the - US Environmental Protection ...

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Numbers of Numbers Published of and Published Unpublished and Unpublished Sources Sources of Existing of Existing Data, by Endpoint
Data, by (as Endpoint of June (as 2004) of June 2004)
Discipline Area Specific Endpoint Published Unpublished Total
Health Effects
Environmental Effects
Environmental Fate
Physicochemical
Properties
As can be seen from the numbers of studies listed in the above table, a significant amount of
As can be seen from the numbers of studies listed in sponsors have proposed (as discussed in the following
unpublished data has now been made public by the sponsors. This indicates that the sponsors,
the above either table, individually a significant or through amount the of many unpublished consortia participating section). When in the isolating Program, the have statistics made for aacute
concerted effort to bring forth such existing data and represents a major success of the HPV
data has now been made public by the sponsors. endpoints (for both health effects and environmental
Challenge Program. It also indicates that many sponsors made significant efforts to evaluate
This indicates that the sponsors, either individually effects) from the table, it is seen that 75% of acute
or through the many consortia participating in the
Program, have made a concerted effort to bring forth
such existing data and represents a major success of
the HPV Challenge Program. It also indicates that
many sponsors made significant efforts to evaluate
the hazards of their chemicals prior to the launch of
the HPV Challenge Program, but often did not make
those underlying data available to the public.
The submission of existing, unpublished data has had
a significant effect on the amount of new testing that
Acute-Oral 357 864 1221
Acute-Inhalation 138 346 484
Acute-Dermal 101 472 573
Repeat Dose 556 682 1238
Gene Tox-In-Vitro 901 889 1790
Gene Tox-In-Vivo 303 275 578
Repro/Dev 459 431 890
Subtotal 2815 3959 6774
Acute-Fish 223 639 862
Acute-Daphnid 154 490 644
Acute-Algae 94 312 406
Subtotal 471 1441 1912
Biodegradation 308 590 898
Subtotal 308 590 898
Water Solubility 319 224 543
Vapor Pressure 278 221 499
Partition Coefficient 183 189 372
Boiling Point 426 177 603
Subtotal 1206 811 2017
Totals (41%) 4800 (59%) 6801 (100%) 11601
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studies were unpublished. The 75% value greatly
Status and Future Directions of the HPV Challenge Program – Final Draft – 10/19/04
contrasts the 50% value for unpublished studies for
all other endpoints and can possibly be explained by a
previously lower interest in publishing acute studies.
Data Development Strategies Described in Test
Plans
The following analysis is directly related to the above
discussion and shows how sponsors have proposed
to address the SIDS endpoints. EPA analyzed test
EPA’s High Production Volume Challenge Program
plans for which comments were due through June
2004 to determine how the health and environmental
effects endpoints were addressed. Three methods were
available to meet the minimum data needs for each
SIDS endpoint. Data needs were met by:
■ Using existing scientifically adequate data,
■ Using an estimation technique such as Structure
Activity Relationship (SAR) or “read-across”
categories, or
■ Proposing new testing.
For human health effects, five endpoints (acute,
repeat dose, reproductive, developmental, and genetic
toxicity) were considered. For environmental effects,
three acute toxicity endpoints were examined (acute
toxicity to fish, daphnia, and algae). The 344 reviewed
test plans address 112 categories and 232 single
chemicals.
The figure below illustrates that sponsors have made
maximum use of EPA’s guidance concerning the
Endpoint
Status and Future Directions
Fate
Phys.chem.
Human Health
Ecotoxicity
use of SAR and category proposals. Additionally,
and in combination with the significant amount of
unpublished data made available through the robust
summaries, only a minimal amount of new testing
has been proposed. Overall, for physicochemical and
fate endpoints, as well as health and environmental
effects, fewer than 10% of the endpoints are proposed
to be addressed with new testing. The exact mix and
number of new tests may change as sponsors consider
EPA and public comments and the remainder of
test plans is submitted; however, there is no reason
to believe that the overall conclusions will change
significantly. Comments could lead to some additional
tests being performed, but could also result in fewer
tests. Perhaps the most striking conclusion from these
statistics and the illustration below is that most of the
data existed, but were simply unpublished. Consistent
with that conclusion is how relatively little new testing
is being contemplated.
Endpoint Data Sources (as of June 2004)
0 10 20 30 40 50 60 70
Percent
Existing Data
Estimate/SAR/
Read Across
Proposed Testing
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