![](media/image1.wmf){width="1.0798611111111112in" height="1.2in"}

**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY**

**WASHINGTON, D.C. 20460**

**OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES**

April 10, 2007

**MEMORANDUM**

**SUBJECT**: Review of Fenoxaprop Incident Reports

DP Barcode D338156 Chemical #128701

**FROM**: Monica Hawkins, M.P.H., Environmental Health Scientist

Chemistry and Exposure Branch

Health Effects Division (7509P)

Hans Allender, Ph.D., Statistician

Chemistry and Exposure Branch

Health Effects Division (7509P)

**THRU**: David J. Miller, Chief

Chemistry and Exposure Branch

Health Effects Division (7509P)

**TO**: Kylie Rothwell, Chemical Review Manager

Special Review and Reregistration Division (7508P)

**BACKGROUND**

To generate this review, the Office of Pesticides (OPP) consulted the
following databases for the poisoning incidents on the active ingredient
Fenoxaprop. The purpose of the database searches is to identify
potential patterns of the extent and severity of the health effects
attributed to Fenoxaprop exposure.

**1)** **[Poison Control Centers]{.underline}** -- OPP purchases
American Association of Poison Control Center (AAPCC) data covering the
years 1993 through 2005 for all reported pesticides incidents. The last
acquisition of data covering 2004 and 2005 took place in late 2006. Most
of the national Poison Control Centers (PCCs) participate in a national
data collection system, previously called The Toxic Exposure
Surveillance System (TESS). PCC reports includes 61 centers at hospital
and universities that cover 100% of the United States population.
Datasets incorporate an extensive quality assurance process including a
standardized computer-based data collection. Some PCCs cover multiple
States; others cover a metropolitan area, or an entire State. PCCs
provide telephone consultation for individual consumers and health care
providers on suspected poisonings, involving drugs, household products,
pesticides, etc.; data collection to aid pesticide regulatory programs
is secondary to this service. An elaborate, computer assisted protocol
is followed by specially trained medical staff, and reports assess
confirmed, possible, probable, or definite pesticide exposures.
Approximately 50% of base reports include medical follow-up and clinical
outcome are determined, e.g., cases resolved by phone consultation with
PCC specialist, patients seen in health care facility, patients
hospitalized, and patients admitted to Intensive Care Unit (ICU) and in
some cases death. PCCs receive calls 24 hours a day throughout the
entire year, and they handle non-occupational as well as occupational
calls. Discussions are underway to improve collection of OPP-specific
occupational data. Because mainly consumers initiate PCC calls, this
database is not currently a complete source of occupational poisoning
incidents.

**2) [OPP Incident Data System]{.underline} (IDS)** This database
includes reports of incidents from various sources, including mandatory
Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) Section 6 (a)
(2) reports from registrants, other federal and state health and
environmental agencies and individual consumers. The IDS has been in
existence since 1992. Reports submitted to the Incident Data System
represent anecdotal reports or allegations only, unless otherwise stated
in this report. Typically, OPP does not draw conclusions implicating the
pesticide as a cause of any of the reported health effects.
Nevertheless, sometimes with enough cases and/or documentation, patterns
and risk mitigation measures may be suggested.

**3) [National Institute of Occupational Safety and Health Sentinel
Event Notification System for Occupational Risks]{.underline}
(NIOSH**/**SENSOR)** performs standardized surveillance in twelve states
from 1998 through 2006. States included in this reporting system are
Arizona, California, Florida, Iowa, Louisiana, Michigan, North Carolina,
New York, New Mexico, Oregon, Texas, and Washington. A number of other
States can and do report, periodically and on request for special
circumstances, because they participate in the NIOSH/ SENSOR network as
part of the Council of State and Territorial Epidemiologists (CSTE).
Reporting is variable from state-to-state because of the dissimilar
cooperation from different sources of reporting (e.g., workers
compensation, Poison Control Centers, emergency departments and
hospitals, enforcement investigations, private physicians, etc.).
Therefore, OPP does not characterize these reports as estimating the
total magnitude of poisoning for a State. The focus of OSHA/SENSOR
database is on occupationally related cases. However, the information
collected on each case is standardized and categorized according to the
certainty of the information collected and the severity of the case.
Detailed exposure circumstances may be available if the State provided
follow-up case reports, as in serious cases ending in death.

The purpose of this review is to summarize available pesticide poisoning
incident data for the active ingredient Fenoxaprop. This report contains
3 sections:

1- Cases reported in the Poison Control Center Database from 1993 to
2005

> 2- Cases reported in the Incident Data System from 1999 to the
> present, and
>
> 3- Cases reported in the NIOSH system from 1998 to 2003.

**1. Number range CHAPTER[Poison Control Center Data --
1993-2005]{.underline}**

This section discusses results from the Poison Control Center's Toxic
Exposure Surveillance System (TESS) from the years 1993 through 2005 and
reflects data stratified by population: occupational, non-occupational,
and children. The children class is five years of age or less; this
definition includes children about to become six years old, or up to 72
months old. Cases involving exposures to multiple products and cases
with unrelated medical outcome are excluded. Also excluded are
intentional exposures, i.e., suicide attempts. The tables incorporated
in this section contain summaries of acute pesticide poisoning incidents
resulting from exposure to Fenoxaprop.

The following tables evaluate the frequency of poisoning incidents for
Fenoxaprop compared to the composite of [all]{.underline} pesticides for
which the PCC received a non-excluded incident report. The tables report
the frequency of events by health severity category (i.e.; all symptoms,
moderate, and major) and by level of health care received. A comparative
ratio provides a simple measure of the relative frequency of reported
health effects by severity category. Knowledge of the ratios of symptoms
for a single chemical (or a group of chemicals) provides a relative
measure of the public health impact of the acute pesticide events. In
addition, a Likelihood Ratio test shows whether the compound under study
is significantly different from the average of all other pesticides. An
(**s**) next to the ratio indicates the proportions are significantly
different.

For a detailed explanation of the tables, [**see** **Attachment
2**]{.underline}.

**[Occupational Cases.]{.underline}** Only five cases of exposure to
Fenoxaprop were reported for the occupational class in the 13-year span
of PCC data available. Only three of these cases presented minor
symptoms with no case presenting moderate or major symptoms.

**[Non-Occupational cases.]{.underline}** The following table 1
summarizes this class.

**Table 1**. **Relative Frequency of Acute Poisoning Incidents by
Symptom Severity: [Non-Occupational Cases]{.underline}**

+-------------------+-------+-------+-------+-------+-------+-------+
|                   | **Sev |       |       | **To  | **H   |       |
|                   | erity |       |       | tal** | ealth |       |
|                   | of    |       |       |       | c     |       |
|                   | outc  |       |       | *     | are** |       |
|                   | ome** |       |       | *expo |       |       |
|                   |       |       |       | sed** | **    |       |
|                   | **(ou |       |       |       | provi |       |
|                   | tcome |       |       |       | ded** |       |
|                   | det   |       |       |       |       |       |
|                   | ermin |       |       |       |       |       |
|                   | ed)** |       |       |       |       |       |
+===================+=======+=======+=======+=======+=======+=======+
| **Denominator     | **6** |       |       | *     | **2** |       |
| numbers**         |       |       |       | *14** |       |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Measures**      | **SYM | **MOD | **MAJ | **HCF | *     | **ICU |
|                   | ^1^** | ^2^** | ^3^** | ^4^** | *HOSP | ^6^** |
|                   |       |       |       |       | ^5^** |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Numerator       | **4** | **2** | **1** | **2** | **0** | **0** |
| numbers**         |       |       |       |       |       |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Fenoxaprop      | **66. | **33. | **16. | **14. | **0.  | **0.  |
| percents**        | 67%** | 33%** | 67%** | 29%** | 00%** | 00%** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **All Pesticides  | **64. | **10. | **0.  | **15. | **7.  | **3.  |
| percents**        | 72%** | 61%** | 45%** | 45%** | 94%** | 02%** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Ratio of        | **1   | **3   | **    | **0   | **0   | **0   |
| Fenoxaprop**      | .03** | .14** | 37.04 | .92** | .00** | .00** |
|                   |       |       | (S)** |       |       |       |
| **/All            | **P   | **P = |       | **P = | **P = | **P   |
| pesticides**      | =0    | 0     | **P = | 0     | 0     | =0    |
|                   | .92** | .07** | 0.00  | .90** | .67** | .80** |
|                   |       |       | (     |       |       |       |
|                   |       |       | \*)** |       |       |       |
+-------------------+-------+-------+-------+-------+-------+-------+

1\) Percent of cases with ANY symptom in relation to the total of cases
followed; 2) Percent with moderate symptoms in relation to the total of
cases followed; 3) Percent with major or fatal outcome in relation to
the total of cases followed; 4) Percent of case seen in a Health Care
Facility (HCF) in relation to total exposures; 5) Percent of cases seen
in a Hospital in relation to cases seen in a HCF; 6) percent of cases
taken to an Intensive Care Unit (ICU) in relation to cases seen in a
HCF.

**(\*) Sample size not big enough for a reliable test.**

**[Children Cases]{.underline}**

In the children class, only four exposures to Fenoxaprop were reported
by PCC from 1993 to 2005. None of the cases was symptomatic or required
a visit to a health care facility.

**Table 2**. **Relative Frequency of Acute Poisoning Incidents by
Symptom Severity: [Combination of All Cases Regardless
Class]{.underline}**

+-------------------+-------+-------+-------+-------+-------+-------+
|                   | **Sev |       |       | **To  | **H   |       |
|                   | erity |       |       | tal** | ealth |       |
|                   | of    |       |       |       | c     |       |
|                   | outc  |       |       | *     | are** |       |
|                   | ome** |       |       | *expo |       |       |
|                   |       |       |       | sed** | **    |       |
|                   | **(ou |       |       |       | provi |       |
|                   | tcome |       |       |       | ded** |       |
|                   | det   |       |       |       |       |       |
|                   | ermin |       |       |       |       |       |
|                   | ed)** |       |       |       |       |       |
+===================+=======+=======+=======+=======+=======+=======+
| **Denominator     | **9** |       |       | *     | **5** |       |
| numbers**         |       |       |       | *23** |       |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Measures**      | **SYM | **MOD | **MAJ | **HCF | *     | **ICU |
|                   | ^1^** | ^2^** | ^3^** | ^4^** | *HOSP | ^6^** |
|                   |       |       |       |       | ^5^** |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Numerator       | **7** | **2** | **1** | **5** | **0** | **0** |
| numbers**         |       |       |       |       |       |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Fenoxaprop      | **77. | **22. | **11. | **21. | **0.  | **0.  |
| percents**        | 78%** | 22%** | 11%** | 74%** | 00%** | 00%** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **All Pesticides  | **42. | **6.  | **0.  | **16. | **6.  | **2.  |
| percents**        | 69%** | 02%** | 29%** | 01%** | 05%** | 16%** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Ratio of        | *     | *     | **    | **1   | **0   | **0   |
| Fenoxaprop**      | *1.82 | *3.69 | 38.31 | .36** | .00** | .00** |
|                   | (S)** | (S)** | (S)** |       |       |       |
| **/All            |       |       |       | **P = | **P = | **P   |
| pesticides**      | **P   | **P = | **P = | 0     | 0     | =0    |
|                   | =0    | 0     | 0.00  | .45** | .22** | .47** |
|                   | .03** | .04** | (     |       |       |       |
|                   |       |       | \*)** |       |       |       |
+-------------------+-------+-------+-------+-------+-------+-------+

1\) Percent of cases with ANY symptom in relation to the total of cases
followed; 2) Percent with moderate symptoms in relation to the total of
cases followed; 3) Percent with major or fatal outcome in relation to
the total of cases followed; 4) Percent of case seen in a Health Care
Facility (HCF) in relation to total exposures; 5) Percent of cases seen
in a Hospital in relation to cases seen in a HCF; 6) percent of cases
taken to an Intensive Care Unit (ICU) in relation to cases seen in a
HCF.

**(\*) Sample size not big enough for a reliable test.**

Table 3 provides a summary by year, and Figure 1 shows a graphic summary
for yearly exposures cases, symptomatic cases, and cases seen in a
health care facility.

**Table 3. Summary of Cases by Year**

+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **Su  |         |        |     |        |       |     |     |     |
| mmary |         |        |     |        |       |     |     |     |
| of    |         |        |     |        |       |     |     |     |
| Cases |         |        |     |        |       |     |     |     |
| by    |         |        |     |        |       |     |     |     |
| Y     |         |        |     |        |       |     |     |     |
| ear** |         |        |     |        |       |     |     |     |
+=======+=========+========+=====+========+=======+=====+=====+=====+
| **Y   | *       | **Mode | **M | **C    | **    | *   | **H | *   |
| ear** | *Sympto | rate** | ajo | ases** | Total | *HC | osp | *IC |
|       | matic** |        | r** |        | Expo  | F** | ita | U** |
|       |         | **C    |     | **Foll | sed** |     | l** |     |
|       | **      | ases** | **C | owed** |       | **C |     | **C |
|       | Cases** |        | ase |        |       | ase | **C | ase |
|       |         |        | s** |        |       | s** | ase | s** |
|       |         |        |     |        |       |     | s** |     |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **2**   | **0**  | **  | **2**  | **2** | **  | **  | **  |
| 993** |         |        | 0** |        |       | 2** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **0**   | **0**  | **  | **0**  | **1** | **  | **  | **  |
| 994** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **1**   | **0**  | **  | **1**  | **1** | **  | **  | **  |
| 995** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **1**   | **0**  | **  | **1**  | **1** | **  | **  | **  |
| 996** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **0**   | **0**  | **  | **0**  | **0** | **  | **  | **  |
| 997** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **0**   | **0**  | **  | **0**  | **4** | **  | **  | **  |
| 998** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **1   | **0**   | **0**  | **  | **0**  | **1** | **  | **  | **  |
| 999** |         |        | 0** |        |       | 1** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **2   | **1**   | **1**  | **  | **1**  | **4** | **  | **  | **  |
| 000** |         |        | 1** |        |       | 2** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **2   | **1**   | **0**  | **  | **2**  | **2** | **  | **  | **  |
| 001** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **2   | **1**   | **1**  | **  | **1**  | **4** | **  | **  | **  |
| 002** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **2   | **0**   | **0**  | **  | **0**  | **1** | **  | **  | **  |
| 003** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **2   | **0**   | **0**  | **  | **0**  | **0** | **  | **  | **  |
| 004** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **2   | **0**   | **0**  | **  | **1**  | **2** | **  | **  | **  |
| 005** |         |        | 0** |        |       | 0** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+
| **To  | **7**   | **2**  | **  | **9**  | *     | **  | **  | **  |
| tal** |         |        | 1** |        | *23** | 5** | 0** | 0** |
+-------+---------+--------+-----+--------+-------+-----+-----+-----+

**Figure 1** Total exposure, symptomatic cases, and cases sent to HCF by
year

![](media/image2.wmf){width="6.495833333333334in" height="4.95in"}

**[Analysis of Results]{.underline}**

The main characteristic of exposures to Fenoxaprop is its low rate of
exposure with 23 exposures in the13-year period and only 7 symptomatic
cases in the entire population. Exposures for the classes Occupational
and Children are almost non-existent with five and four cases each. The
non-occupational class presents the most cases with 14 cases with one
case reported as major health effect; however, this case did not present
any long-term effect and doctors released the individual quickly.

No trend in total exposure, symptomatic cases, and cases seen in a HCF
is apparent for the 13 year-span of data collected on Fenoxaprop, with
no case send to a HCF since 2001. Calculations show an average of about
1.73 exposures per year, 0.54 symptomatic cases per year, and 0.38 cases
per year seen in a heath care facility.

**2. [Cases reported in the Incident Data System from 1999 to the
present]{.underline}**

Three cases were reported in the IDS. For a detailed description, see
attachment 1.

**3. [NIOSH SENSOR]{.underline}**

Out of 5,899 reported cases from 1998 to 2003, no case was reported in
the SENSOR database involving Fenoxaprop.

**[Study Summary]{.underline}**

The summary findings for the period 1993 to 2005 for Fenoxaprop are:

-   Fenoxaprop has a low incidence of cases in the population, with only
    23 exposures and seven symptomatic cases in the 13 year-span of data
    collected.

-   Fenoxaprop data shows very low averages of about 1.73
    exposures/year, 0.54 symptomatic cases/year, and 0.38 cases/year
    seen in a heath care facility.

-   No apparent annual trend is apparent in the 13 year-span, in
    addition, no case has visited a HCF since 2001.

**[Recommendations]{.underline}**

Based on the incident data reviewed from the above sources, OPP suggests
no mitigation actions for Fenoxaprop at this time.

**Attachment 1.**

**Cases from the Incident Data System for Fenoxaprop**

Incident#2796-222

A pesticide incident occurred in 1994, when the product drifted from a
field into gardens. An individual reported dampness on his face. No
further information on the disposition of the case was reported.

Incident#3037-102

A pesticide incident occurred in 1994, when a pilot died after their
crop duster crashed. The incident was not related to exposure of the
product. No further information on the disposition of the case was
reported.

Incident#7155-66

A pesticide incident occurred in 1996, when a parcel service worker
moved a box of the product and he put it down some of the powder got
into his face. The worker was asymptomatic. No further information on
the disposition of the case was reported.

**Attachment 2.**

**Table Description**

The following is a general description of the table components that
compares the pesticide of interest with the composite average of all
pesticides. The table produces ratios in several health and exposure
measurements.

**Table 1 General Explanation of Comparison of the Pesticide of Interest
with the Composite Average of all Pesticides.**

+-------------------+-------+-------+-------+-------+-------+-------+
|                   | **Sev |       |       | **To  | **H   |       |
|                   | erity |       |       | tal** | ealth |       |
|                   | of    |       |       |       | C     |       |
|                   | Outc  |       |       | *     | are** |       |
|                   | ome** |       |       | *Expo |       |       |
|                   |       |       |       | sed** | **    |       |
|                   | **(Ou |       |       |       | Provi |       |
|                   | tcome |       |       |       | ded** |       |
|                   | det   |       |       |       |       |       |
|                   | ermin |       |       |       |       |       |
|                   | ed)** |       |       |       |       |       |
+===================+=======+=======+=======+=======+=======+=======+
| **Denominator     | **25, |       |       | **68, | **18, |       |
| numbers**         | 549** |       |       | 005** | 084** |       |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Measures**      | **    | **    | **    | **    | **H   | **    |
|                   | SYM** | MOD** | MAJ** | HCF** | OSP** | ICU** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Numerator       | **    | *     | **9** | **18, | **    | **    |
| numbers**         | 578** | *83** |       | 084** | 302** | 219** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Pesticide "X"   | **2.  | **0.  | **0.  | **26. | **1.  | **1.  |
| percents**        | 26%** | 32%** | 03%** | 59%** | 67%** | 21%** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **All Pesticides  | **21. | **1.  | **0.  | **15. | **4.  | **1.  |
| percents**        | 72%** | 42%** | 12%** | 68%** | 34%** | 75%** |
+-------------------+-------+-------+-------+-------+-------+-------+
| **Ratio of "X"**  | *     | *     | *     | *     | *     | **0   |
|                   | *0.10 | *0.23 | *0.25 | *1.69 | *0.38 | .69** |
| **to average of   | (S)** | (S)** | (S)** | (S)** | (S)** |       |
| all pesticides**  |       |       |       |       |       | **P   |
|                   | **P   | **P = | **P = | **P = | **P = | =0    |
|                   | =0    | 0     | 0     | 0     | 0     | .51** |
|                   | .00** | .00** | .01** | .00** | .00** |       |
+-------------------+-------+-------+-------+-------+-------+-------+

> **A)** The firs row, or title row, divides the table in three
> sub-tables "Severity of Outcome", "Total Exposed", and "Health Care
> Provided"
>
> **B)** The second row "Denominator numbers" presents the numbers
> extracted from the PCC database for the pesticide of interest "X" that
> will serve as denominators in the calculation of the percents, and
> they are:

a.  In the center column, total amount of individuals exposed to
    pesticide "X" (n = 68,005) or "Total Exposed". These are cases
    collected by the Poison Control Center for the period of interest
    regardless of outcome.

b.  In the left column under "Severity of Outcome", is the number of
    cases followed, (n = 25,546). These cases have an outcome determined
    "Outcome determined" and these cases may or may not have symptoms.

c.  At the right of the table, cases that visited a Health Care Facility
    (n = 18084) "Health Care Provided".

> **C)** The third row "Measures" describes the clinical outcome and
> level of care required for the exposed cases:

-   "SYM" are those cases that were symptomatic;

-   "MOD" cases are those that were classified with moderate symptoms;

-   "MAJ" cases were cases classified as major symptoms or fatal
    outcome;

-   "HCF" are cases that went to a Health Care Facility;

-   "HOSP" are cases that went to a hospital; and

-   "ICU" are cases that went to an Intensive Care Unit.

> **D)** The fourth row "Numerator numbers" is actually the number of
> cases for pesticide "X" that presented the outcome describe in the
> "Measures" row. The numbers in this row are inclusive. This is, a case
> classified as "Major", is first classified as "Symptomatic", and also
> classified as "Moderate"; so a "Major" case will count on the three
> measurements. The same scenario applies to the "Health Care Provided"
> section; a case classified as "ICU" also counts as a case that went to
> a "HCF" and to a "Hospital". In addition, a case classified as
> "Hospital" will count also in "HCF" but not on "ICU"
>
> **E)** The fifth row "Pesticide "X" percents" gives the percentages on
> each measure. These percentages are calculated by dividing the
> numerator number by the denominator number (from each major section of
> the Table 1) and multiplying by 100. For example, to calculate SYM,
> MOD, and MAJ, the numbers 578, 83 and 9 are divided by 25,549 on the
> first row, producing the respective percents 2.26%, 0.32%, and 0.03%.
> In a similar fashion 18,084 is divided by 68,005 for the percentage of
> cases seen in a HCF of 26.59%; and for the last section of the fifth
> row, 302 and 219 are divided by 18,084 to find the percentages, 1.67%
> and 1.21%, of cases that went to a "Hospital" and "ICU".
>
> **F)** The sixth row "All Pesticides Percents" are percentages that
> were previously calculated using all pesticide cases available in the
> PCC database with the exception of cases involving exposures to
> multiple products, cases with unrelated medical outcome, and cases
> where the exposure was intentional. These exclusions make the
> comparison more meaningful for US EPA regulatory program purposes. The
> percentages serve as the baseline for the comparison with a single
> pesticide or a group. These percentages are a unique characteristic
> for the "class" and "period" of the data assembled in the table, and
> are completely independent of the previously calculated values for
> pesticide "X".

**G)** The last row **"**Ratio of "X" to average of all pesticides**"**
is obtained by dividing the percentages of the "X" compound by the "all
pesticides" percentages, to obtain a dimensionless number or ratio. This
ratio provides an idea of the relative frequency of the compound "X".
For example, a ratio of 1 (one) indicates that the percentages are the
same for the compound "X" and the composite of all pesticides; a ratio,
say of 2 (two), indicates that the chemical under study produces twice
the effect; and a ratio of 0.5 indicates that the compound has half of
the activity of the composite average. These ratios provide a quick
overview of the relative toxicity of the chemical.

> **H)** Also, the "p" value that results from a Likelihood ratio test
> is entered in the ratio cell and when significant (p \< 0.05) then an
> **(S)** is entered next to the ratio to mark statistical significance.
> A cell marked with **(S)** means that the percentages that produce the
> ratios are "statistically" different and not due to chance. The
> percentage of pesticide "X" could be higher or lower than the
> percentage produce by the composite as indicated by the ratio.
> However, when mark by an (S) the difference is significant. For
> example, a ratio = 1.6 **(S)** means the effect produced by the
> compound is higher that the effect produced by the composite and
> statistically different; a ratio = 0.7 **(S)** signifies that
> pesticide "X" has a lower effect than the composite and is
> statistically different. On the other hand, a ratio = 1.2, with no
> **(S)**, means that the percentage, although higher, is not
> statistically different from the composite.