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CHAPTERUNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

March 31, 2008

**[MEMORANDUM]{.underline}**

SUBJECT: Creosote: Occupational and Residential Exposure and Risk
Assessment for the Reregistration Eligibility Decision (RED). PC Codes
022003, 025003, and 025004.

FROM: Timothy Leighton, Environmental Scientist

> Regulatory Management Branch II

Antimicrobials Division

THRU: Norm Cook, Branch Chief

> Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division

TO: Jacqueline Campbell-McFarlaneNumber range CHAPTER, Chemical Review
Manager

> Antimicrobials Division
>
> And
>
> Timothy F. McMahon, Ph.D., Senior Toxicologist
>
> Antimicrobials Division

[Table of Contents]{.smallcaps} [2]{.smallcaps}

[Executive Summary]{.smallcaps} 3

[1.0
Introduction.............................................................................................5]{.smallcaps}

2.0 Summary of Toxicity
Data...............................................................\...............5
2.1 Acute Toxicology Categories 7

2.2 Summary of Endpoints of
Concern...............................................................\....7

2.3 FQPA
Consideration..................................................................................9

[3.0 Occupational Exposures and Risks at Pressure Treatment
Facilities]{.smallcaps} 9

3.1 Worker Exposure at Pressure Treatment Facilities 12

3.1.1 Pressure Treatment Process 12

3.1.2 Dermal Exposure Monitoring 13

3.1.3 Inhalation Exposure
Monitoring............................................................\...14

3.1.4 Exposure and Risk
Characterization..........................................................15

3.2 Post-Application Exposures and Risks 20

[4.0 Summary of Literature Exposure
Studies.......................................................20]{.smallcaps}

[5.0 Uncertainties and Limitations]{.smallcaps} 24

[6.0 References]{.smallcaps} 26

**EXECUTIVE SUMMARY**

Creosote applications are limited to occupational handlers at pressure
treatment facilities. Since it is a restricted-use pesticide that can
only be applied by certified applicators or someone under their direct
supervision, it is not available for sale to or use by homeowners. A
recent voluntary cancellation of all non pressure treatment uses
restricts creosote to commercial and industrial settings.

This chapter is a revision of the earlier draft Human Exposure RED
Chapter for Creosote completed in 2003. Subsequent to the last release
of the creosote assessment, additional data were made available to
further refine the assessment. The previous version of the human risk
assessment was based on relying on benzo(a)pyrene as an indicator of
creosote risk because creosote-specific data were not available. Data
are now available to relate dermal absorption and cancer risks to
creosote. The previous draft risk assessment also included scenarios
using data from the Pesticide Handlers Exposure Database (PHED) and the
Chemical Manufactures Association (CMA). These scenarios have been
deleted in this current assessment based on the voluntary cancellation
of all non pressure treatment uses of creosote.

The results of the Creosote Council's worker exposure study (MRID
453234-01) at pressure treatment facilities indicate that the
naphthalene inhalation exposures trigger EPA's non cancer risk level of
concern for 16 of the 19 inhalation MOEs assessed. The non cancer
inhalation MOEs for worker exposure to naphthalene range from 23 to
1,900 (i.e., target MOE of 300). However, none of the average
naphthalene air concentrations for the various job functions exceeded
the ACGIH TLV and OSHA PEL of 52 mg/m^3^. Furthermore, the published
literature for creosote exposure also indicates naphthalene air
concentrations in the range of that monitored in MRID 453234-01, with
some upper ends of the range slightly higher (but those concentrations
are for "total vapor"). The results of the air concentrations reported
in the literature support the results of the Creosote Council's worker
exposure study indicating that exposure to creosote should be reduced.

For dermal worker risks, the results indicate the short-term (ST) non
cancer dermal MOEs do not trigger a risk concern except for the
treatment operator at site C where the dermal MOE is 68 and the target
MOE is 100. The intermediate-term (IT) non cancer dermal MOEs trigger
risk concerns for 8 of the 24 scenarios presented. IT MOEs range from 3
to 2700 and the target MOE is 100. The long-term (LT) non cancer dermal
MOEs trigger risk concerns for 3 of the 24 scenarios. LT MOEs range from
34 to 34,000 and the target MOE is 300. IT risks being greater than the
LT risks is an anomaly. However, in the case of creosote it is
explainable because the IT toxicity endpoint is based on a dermal study
while the LT endpoint is based on an oral study (i.e., there are
differences in routes of exposure and dosing levels between the two
studies).

All of the cancer risks exceed the Agency's level of concern of 1 x
10^-6^ but only 4 of the scenarios had risks exceeding 1 x 10^-4^ (i.e.,
risks range from 2.5 x 10^-5^ to 1.6 x 10^-6^).

The registrants submitted a probabilistic worker risk assessment for
creosote in February 2008. This probabilistic assessment has been
included in the public docket. A thorough EPA review of the
probabilistic assessment has not been conducted. The methodology and
data inputs in this recent submission differ from that presented by EPA.
EPA's assessment herein presents a deterministic risk assessment. In
summary, the Creosote Council's probabilistic assessment includes cancer
risk results with and without the probabilistic analysis of the cancer
slope factor. The mean and 95^th^ percentile cancer risks reported in
Table 9 of the Creosote Council's probabilistic assessment range from
10^-4^ to 10^-5^. These reported risks are within the range of the risks
presented by EPA in Table 6 of Section 3.1.4 below. However, EPA's
assessment reports one cancer risk lower than that reported in the
probabilistic assessment (i.e., 1.6 x 10^-3^ for the treatment operators
at a facility built in the 1940s).

**1.0 Introduction**

An occupational and/or residential exposure risk assessment is required
for an active ingredient if (1) certain toxicological criteria are
triggered [and]{.underline} (2) there is potential exposure to handlers
(mixers, loaders, applicators, etc.) during use or to persons entering
treated sites after application is complete. For creosote, both criteria
are met.

On April 1, 1999, the EPA/OPP Health Effects Division\'s Hazard
Identification Assessment Review Committee (HIARC) evaluated the
toxicology data base of creosote and selected toxicological endpoints
for short-term, intermediate-term, and long-term occupational and
residential exposure risk assessments. On September 3, 2003, the
Antimicrobials Division Toxicity Endpoint Selection Committee (ADTC) met
to verify the selected endpoints for dermal and inhalation risk
assessment. On December 6, 2007, members of the Antimicrobials
Division's Toxicity Endpoint Selection Committee and members of the
Health Effects Division's Carcinogenicity Assessment Review Committee
(CARC) met to discuss the quantitative carcinogenicity analysis
performed for creosote by the Pest Management Regulatory Agency, Health
Canada and to determine an appropriate potency factor for creosote.

**2.0 Summary of Toxicity Data**

**Dermal Absorption:** Submitted studies on the dermal absorption of
creosote have been submitted and consist of an in vivo dermal absorption
study in the rat as well as an in vitro dermal absorption study using
both rat and human skin (MRIDs 47179501 and 47179502). The results of
these studies support the conclusion that dermal absorption in human
skin is approximately 8-fold lower than that of rat skin. The results of
the submitted studies also support a value for dermal absorption of
creosote in rat skin of approximately 34%. Thus, estimated dermal
absorption of creosote in human skin is determined to be 5% (34% value
divided by 8 and rounded to 5%). A lower dermal absorption value
suggested by the registrant was not used because of the lack of data on
solubility limit of the creosote mixture itself in the in vitro test
system, and the continued absorption of creosote observed after 8 hours
in the in vivo study suggesting the availability of creosote within the
skin for absorption.

**Short-Term Dermal (1 day - 1 month)**: An oral maternal NOAEL of 50
mg/kg/day and a LOAEL of 175 mg/kg/day, based on decreased body weight
gain during the study, was chosen for this endpoint (USEPA, 2008).
Although a 90-day dermal toxicity study was available, the developmental
toxicity study was chosen because dermal toxicity studies (including the
2-week range-finding studies) did not measure developmental endpoints,
which are present in both developmental toxicity studies. An uncertainty
factor (MOE) of 100 is applied to this risk assessment (USEPA, 2008).

**Intermediate-Term Dermal (1 month to 6 months):** A dermal NOAEL of 40
mg/kg/day, based on decreased body weight gain in males at 400 mg/kg/day
observed in the 90-day dermal toxicity study (MRID \# 43616201). An
uncertainty factor (MOE) of 100 is applied to this risk assessment
(USEPA, 2008).

**Long-Term Dermal (greater than 6 months)**: A parental oral LOAEL of
25 mg/kg/day, based on decreased pre-mating body weight, was selected
for this endpoint. An extra uncertainty factor of 3x is applied for use
of a LOAEL in this study for occupational risk assessments
(USEPA, 2008). Based on the results of this study, the Parental Systemic
NOAEL is \< 25 mg/kg/day, and the Parental Systemic LOAEL is 25
mg/kg/day, based on decreased pre-mating body weight. The developmental
NOAEL in this study is \< 25 mg/kg/day, and the developmental LOAEL is
25 mg/kg/day, based on a dose-related decrease in pup body weight for
the F0 pups from days 14-21. The reproductive NOAEL is \< 25 mg/kg/day,
and the reproductive LOAEL is 25 mg/kg/day, based on reduced pregnancy
and fertility indices in F1 female parental rats (USEPA, 2008).

**Inhalation (any time-period)**: An NOAEL of 0.0047 mg/L, based on
decreased body weight gain, altered hematology and clinical chemistry,
and increased absolute and relative weight of the liver and thyroid and
increased incidence of lesions of the nasal cavity observed at 0.048
mg/L in P2 creosote CMT in rats (USEPA, 2008). In a 13-week inhalation
toxicity study (MRID \# 43600901), 20 Sprague-Dawley rats/sex/group were
treated for 5 days/week, 6 hours/day with P2 Creosote CTM via whole body
exposure at doses of 0, 4.7, 48 or 102 mg/m^3^ (0, 0.005, 0.048 or 0.102
mg/L ) in air measured gravimetrically. The aerosol size MMAD was
between 2.4 and 2.9 microns with a geometric standard deviation between
1.85 and 1.91. For worker risk, naphthalene was selected as an indicator
because 100 percent of the inhalation samples monitored at the pressure
treatment facilities were detectable. For naphthalene, the
Antimicrobials Division used the inhalation reference concentration
(RfC) for naphthalene published in the EPA's IRIS database adjusted for
the work week (i.e., EPA recognizes that the 24 hour/day 7 day/week
adjustment to the RfC is not representative of a typical work day). The
RfC was derived from a 2 year chronic inhalation study in the mouse in
which exposure was for 6 hours/day, 5 days/week. The inhalation
route-specific LOAEL is 52 mg/m^3^ with a target MOE of 300 (10x intra
species variability, 10x inter species extrapolation, and 3x for a lack
of a NOAEL).

**Carcinogenicity:** In conjunction with Health Canada's Management
Regulatory Agency (PMRA), a quantitative risk assessment on
carcinogenicity of creosote has been performed using the data of Culp et
al. (1998). A dermal carcinogenicity study by Bushmann et al. (1997) was
also available, but was determined not suitable for quantitative
assessment of carcinogenicity. Ulceration of the skin was significant
finding of the study which potentially affected tumor response. In
addition, systemic toxicity was not examined, and complete
histopathology data were not available. Based upon the analysis of the
Culp et al. data, an oral cancer potency factor of 6.28 x 10^-6^
(µg/kg/day)^-1^ or 6.28 x 10^-3^ (mg/kg/day)^-1^ for the coal tar
mixture 1 tested in this study was selected, on the basis of forestomach
tumors observed.

**2.1 Acute Toxicology Categories**

Table 1 provides the acute toxicity categories for creosote. It also
provides the results of the toxicity tests (USEPA 2008).

**Table 1. Acute Toxicity Categories for Creosote**

  ------------------------------------------------------------------------
  **Test**               **Results**                  **Toxicity
                                                      Category**
  ---------------------- ---------------------------- --------------------
  Acute Oral Toxicity    LD~50~ = 2,451 mg/kg (M);    III
                         1,893 mg/kg (F)              

  Acute Dermal Toxicity  LD~50~ \> 2,000 mg/kg        III

  Acute Inhalation       LC~50~ \> 5 mg/L             IV
  Toxicity                                            

  Primary Eye Irritation Irritation clearing in 8-12  II
                         days                         

  Primary Dermal         Erythema to day 14           III
  Irritation                                          

  Dermal Sensitization   Study unacceptable           NA
  ------------------------------------------------------------------------

NA - Not applicable, no toxicological endpoint.

**2.2 Summary of Endpoints of Concern**

Endpoints for assessing occupational and residential risks are presented
in Table 2 (USEPA 2008).

**Table 2. Summary of Toxicological Endpoints for Creosote.**

+--------------+----------------+---+----------------+---+-------------------+
| **EXPOSURE** | **DOSE**       |   | **ENDPOINT**   | * |                   |
|              |                |   |                | * |                   |
| **SCENARIO** | *              |   |                | S |                   |
|              | *(mg/kg/day)** |   |                | T |                   |
|              |                |   |                | U |                   |
|              |                |   |                | D |                   |
|              |                |   |                | Y |                   |
|              |                |   |                | * |                   |
|              |                |   |                | * |                   |
+==============+================+===+================+===+===================+
| Acute and    | Acute and      |   |                |   |                   |
| Chronic      | Chronic        |   |                |   |                   |
| Dietary      | Dietary risk   |   |                |   |                   |
|              | assessment not |   |                |   |                   |
|              | required       |   |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+
| Car          | Creosote has   |   |                |   |                   |
| cinogenicity | been shown to  |   |                |   |                   |
|              | exert positive |   |                |   |                   |
| (dermal)     | mutagenic      |   |                |   |                   |
|              | effects in     |   |                |   |                   |
|              | vitro, and has |   |                |   |                   |
|              | been shown to  |   |                |   |                   |
|              | be positive    |   |                |   |                   |
|              | for            |   |                |   |                   |
|              | c              |   |                |   |                   |
|              | arcinogenicity |   |                |   |                   |
|              | in an          |   |                |   |                   |
|              | initia         |   |                |   |                   |
|              | tion/promotion |   |                |   |                   |
|              | study.         |   |                |   |                   |
|              | Creosote has   |   |                |   |                   |
|              | been           |   |                |   |                   |
|              | classified as  |   |                |   |                   |
|              | a B1           |   |                |   |                   |
|              | carcinogen in  |   |                |   |                   |
|              | IRIS. An oral  |   |                |   |                   |
|              | cancer slope   |   |                |   |                   |
|              | factor of 6.28 |   |                |   |                   |
|              | x 10^-3^ (mg   |   |                |   |                   |
|              | CT             |   |                |   |                   |
|              | M1/kg/day)^-1^ |   |                |   |                   |
|              | was selected   |   |                |   |                   |
|              | for creosote   |   |                |   |                   |
|              | using the data |   |                |   |                   |
|              | of Culp et al  |   |                |   |                   |
|              | (1998) for the |   |                |   |                   |
|              | coal tar       |   |                |   |                   |
|              | mixture 1      |   |                |   |                   |
|              | (CTM1) on the  |   |                |   |                   |
|              | basis of       |   |                |   |                   |
|              | forestomach    |   |                |   |                   |
|              | tumors.        |   |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+
| Short-Term   | Oral NOAEL=50  |   | decreased body | D |                   |
| (Dermal)     |                |   | weight gain at | e |                   |
|              |                |   | 175 mg/kg/day  | v |                   |
|              |                |   |                | e |                   |
|              |                |   |                | l |                   |
|              |                |   |                | o |                   |
|              |                |   |                | p |                   |
|              |                |   |                | m |                   |
|              |                |   |                | e |                   |
|              |                |   |                | n |                   |
|              |                |   |                | t |                   |
|              |                |   |                | a |                   |
|              |                |   |                | l |                   |
|              |                |   |                | T |                   |
|              |                |   |                | o |                   |
|              |                |   |                | x |                   |
|              |                |   |                | i |                   |
|              |                |   |                | c |                   |
|              |                |   |                | i |                   |
|              |                |   |                | t |                   |
|              |                |   |                | y |                   |
|              |                |   |                |   |                   |
|              |                |   |                | - |                   |
|              |                |   |                | R |                   |
|              |                |   |                | a |                   |
|              |                |   |                | t |                   |
+--------------+----------------+---+----------------+---+-------------------+
|              | MOE = 100 (5%  |   |                |   |                   |
|              | dermal         |   |                |   |                   |
|              | absorption     |   |                |   |                   |
|              | used to        |   |                |   |                   |
|              | correct for    |   |                |   |                   |
|              | use of oral    |   |                |   |                   |
|              | endpoint)      |   |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+
| Inter        | Dermal NOAEL = |   | Decreased body | 9 |                   |
| mediate-term | 40             |   | weight gain at | 0 |                   |
|              |                |   | 400 mg/kg/day  | - |                   |
| (Dermal)     |                |   |                | D |                   |
|              |                |   |                | a |                   |
|              |                |   |                | y |                   |
|              |                |   |                | D |                   |
|              |                |   |                | e |                   |
|              |                |   |                | r |                   |
|              |                |   |                | m |                   |
|              |                |   |                | a |                   |
|              |                |   |                | l |                   |
|              |                |   |                | T |                   |
|              |                |   |                | o |                   |
|              |                |   |                | x |                   |
|              |                |   |                | i |                   |
|              |                |   |                | c |                   |
|              |                |   |                | i |                   |
|              |                |   |                | t |                   |
|              |                |   |                | y |                   |
|              |                |   |                | S |                   |
|              |                |   |                | t |                   |
|              |                |   |                | u |                   |
|              |                |   |                | d |                   |
|              |                |   |                | y |                   |
|              |                |   |                | i |                   |
|              |                |   |                | n |                   |
|              |                |   |                | t |                   |
|              |                |   |                | h |                   |
|              |                |   |                | e |                   |
|              |                |   |                | R |                   |
|              |                |   |                | a |                   |
|              |                |   |                | t |                   |
+--------------+----------------+---+----------------+---+-------------------+
|              | MOE = 100      |   |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+
| Long-Term    | Oral LOAEL =   |   | decreased      | 2 |                   |
| (Dermal)     | 25 mg/kg/day   |   | pre-mating     | - |                   |
|              |                |   | body weight    | g |                   |
|              |                |   |                | e |                   |
|              |                |   |                | n |                   |
|              |                |   |                | e |                   |
|              |                |   |                | r |                   |
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|              |                |   |                | a |                   |
|              |                |   |                | t |                   |
+--------------+----------------+---+----------------+---+-------------------+
|              | MOE = 300 (10x |   |                |   |                   |
|              | interspecies,  |   |                |   |                   |
|              | 10x            |   |                |   |                   |
|              | intraspecies,  |   |                |   |                   |
|              | 3x for use of  |   |                |   |                   |
|              | a LOAEL)       |   |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+
| Inhalation   | Creosote       | M |                |   | 90-day Inhalation |
|              |                | O |                |   | Study in the Rat  |
| (any time    | NOAEL =        | E |                |   |                   |
| period)      | 0.0047mg/m^3^  | = |                |   |                   |
|              |                | 1 |                |   |                   |
|              |                | 0 |                |   |                   |
|              |                | 0 |                |   |                   |
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+--------------+----------------+---+----------------+---+-------------------+
|              | Naphthalene    | n |                |   | Two year          |
|              |                | a |                |   | inhalation        |
|              | LOAEL = 52     | s |                |   | toxicity study -  |
|              | mg/m^3^        | a |                |   | mouse (USEPA,     |
|              |                | l |                |   | IRIS)             |
|              |                | e |                |   |                   |
|              |                | f |                |   |                   |
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|              |                | l |                |   |                   |
|              |                | f |                |   |                   |
|              |                | a |                |   |                   |
|              |                | c |                |   |                   |
|              |                | t |                |   |                   |
|              |                | o |                |   |                   |
|              |                | r |                |   |                   |
|              |                | y |                |   |                   |
|              |                | e |                |   |                   |
|              |                | p |                |   |                   |
|              |                | i |                |   |                   |
|              |                | t |                |   |                   |
|              |                | h |                |   |                   |
|              |                | e |                |   |                   |
|              |                | l |                |   |                   |
|              |                | i |                |   |                   |
|              |                | u |                |   |                   |
|              |                | m |                |   |                   |
|              |                | r |                |   |                   |
|              |                | e |                |   |                   |
|              |                | s |                |   |                   |
|              |                | p |                |   |                   |
|              |                | e |                |   |                   |
|              |                | c |                |   |                   |
|              |                | t |                |   |                   |
|              |                | i |                |   |                   |
|              |                | v |                |   |                   |
|              |                | e |                |   |                   |
|              |                | l |                |   |                   |
|              |                | y |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+
| Dermal       | 5%, determined |   |                |   |                   |
| absorption   | from the       |   |                |   |                   |
|              | results of in  |   |                |   |                   |
|              | vivo / in      |   |                |   |                   |
|              | vitro testing  |   |                |   |                   |
|              | in rats and in |   |                |   |                   |
|              | vitro testing  |   |                |   |                   |
|              | using human    |   |                |   |                   |
|              | skin.          |   |                |   |                   |
+--------------+----------------+---+----------------+---+-------------------+

**2.3 FQPA Considerations**

As there are no existing tolerances or other clearances for residues of
creosote in food, an FQPA assessment is not necessary. The available
evidence on developmental and reproductive effects of creosote was
assessed by the Health Effects Division (HED) Hazard Identification
Assessment Review Committee on April 1, 1999. The committee expressed
concern for potential infants and children's susceptibility of creosote,
based on the severity of offspring vs. maternal effects observed with
testing of creosote in the P1/P13 blend developmental toxicity study in
rats at the 175 mg/kg/day dose level as well as deficiencies observed in
the 2-generation reproduction toxicity study in rats.

Although there are no current Agency guideline neurotoxicity studies
available for creosote, the existing studies on creosote indicate no
evidence of neurotoxicity for either the P1/P13 or P2 blends of creosote
(ATSDR, 2002). Based on the above, and realizing that creosote is
currently registered only for non -food use and is a restricted use
pesticide, no additional neurotoxicity testing will be required at this
time.

**3.0 Occupational Exposures and Risks at Pressure Treatment
Facilities**

Creosote is used by occupational handlers only. Since it is a
restricted-use pesticide that can only be applied by certified
applicators or someone under their direct supervision, it is not
available for sale to or use by homeowners. Furthermore, the non
pressure treatments of creosote have been voluntarily cancelled by the
registrants. Creosote applications are now restricted to pressure
treatment cylinders.

EPA has determined that there are potential exposures to mixers,
loaders, applicators, and other handlers during typical use-patterns
associated with creosote pressure treatment uses. Table 3 provides a
summary of worker exposure scenarios at pressure treatment facilities.
Although specific job functions have been defined within each exposure
scenario, EPA acknowledges the occasional need for workers to cross over
into other job functions. Table 3 also provides the numbers of
monitoring events at each of four sites from MRID 453234-01.

+-----------+----------------------------------+----+-------+--------+
| **Table   |                                  |    |       |        |
| 3: Job    |                                  |    |       |        |
| Des       |                                  |    |       |        |
| criptions |                                  |    |       |        |
| of        |                                  |    |       |        |
| Workers   |                                  |    |       |        |
| Exposed   |                                  |    |       |        |
| at        |                                  |    |       |        |
| Pressure  |                                  |    |       |        |
| Treatment |                                  |    |       |        |
| F         |                                  |    |       |        |
| acilities |                                  |    |       |        |
| (Creosote |                                  |    |       |        |
| Council   |                                  |    |       |        |
| Study --  |                                  |    |       |        |
| MRID      |                                  |    |       |        |
| 4532      |                                  |    |       |        |
| 34-01).** |                                  |    |       |        |
+===========+==================================+====+=======+========+
| **Job     | **Description of worker          | ** |       |        |
| F         | activities**                     | Mo |       |        |
| unction** |                                  | ni |       |        |
|           |                                  | to |       |        |
|           |                                  | ri |       |        |
|           |                                  | ng |       |        |
|           |                                  | Ev |       |        |
|           |                                  | en |       |        |
|           |                                  | ts |       |        |
|           |                                  | ** |       |        |
+-----------+----------------------------------+----+-------+--------+
|           |                                  | ** | **Der | **     |
|           |                                  | Si | mal** | Inhala |
|           |                                  | te |       | tion** |
|           |                                  | ** |       |        |
+-----------+----------------------------------+----+-------+--------+
| Treatment | Operates and manages the         | A  | t     | total: |
| Operator  | treatment system; may open and   |    | otal: | 14     |
| TO        | close cylinder doors; cleans     | B  | 18 4, |        |
| (         | accumulated creosote from doors  |    | 1/day | 0      |
| engineer) | and latches; operates valves to  | C  |       |        |
|           | transfer creosote solution       |    | 4,    | 4,     |
|           | between holding tanks and        | D  | 1/day | 1/day  |
|           | treatment cylinders; handles     |    |       |        |
|           | leads and bands.                 |    | 5,    | 5,     |
|           |                                  |    | 1/day | 1/day  |
|           |                                  |    |       |        |
|           |                                  |    | 5,    | 5,     |
|           |                                  |    | 1/day | 1/day  |
+-----------+----------------------------------+----+-------+--------+
| Treatment | Performs and assists with tasks  | B  | t     | total: |
| Assistant | of the TO; charge preparation,   |    | otal: | 4      |
| TA        | cylinder cleaning, maintenance,  |    | 4     |        |
| (helper)  | filter cleaning, mixing          |    |       | 4,     |
|           | treatment solution; loader       |    | 4,    | 1/day  |
|           | operation and movement of        |    | 1/day |        |
|           | charges.                         |    |       |        |
+-----------+----------------------------------+----+-------+--------+
| Oil       | Operates creosote tank car       | A  | t     | total: |
| unloader  | unloading and transfer system;   |    | otal: | 5      |
|           | takes samples from tank cars;    | D  | 9     |        |
| OU        | inserts siphons into tanks.      |    |       | 0      |
|           |                                  |    | 4,    |        |
|           | (At site C, the tasks for this   |    | 1/day | 5,     |
|           | position were performed by the   |    |       | 1/day  |
|           | TO; position was not monitored   |    | 5,    |        |
|           | at Site B)                       |    | 1/day |        |
+-----------+----------------------------------+----+-------+--------+
| Loader    | Operates self-propelled vehicles | C  | t     | total: |
| Operator  | for loading wood on and off      | LO | otal: | 14     |
|           | trams, moving charges in and out |    | 18    |        |
| CLO       | of cylinders, and to and from    | A  |       | 0      |
| (cylinder | load out areas. Out-of-cab tasks |    | 4,    |        |
| area)     | include tram placement, and      | B  | 1/day | 4,     |
|           | handling chains and leads.       |    |       | 1/day  |
| LLO (load |                                  | C  | 4,    |        |
| out area) |                                  |    | 1/day | 5,     |
|           |                                  | D  |       | 1/day  |
|           |                                  |    | 5,    |        |
|           |                                  |    | 1/day | 5,     |
|           |                                  |    |       | 1/day  |
|           |                                  |    | 5,    |        |
|           |                                  |    | 1/day |        |
+-----------+----------------------------------+----+-------+--------+
|           |                                  | L  | t     | total: |
|           |                                  | LO | otal: | 19     |
|           |                                  |    | 19    |        |
|           |                                  | B  |       | 4,     |
|           |                                  |    | 4,    | 1/day  |
|           |                                  | C  | 1/day |        |
|           |                                  |    |       | 5,     |
|           |                                  | D  | 5,    | 1/day  |
|           |                                  |    | 1/day |        |
|           |                                  |    |       | 10,    |
|           |                                  |    | 10,   | 2/day  |
|           |                                  |    | 2/day |        |
+-----------+----------------------------------+----+-------+--------+
| Loader    | Assists the LO in some tasks;    | B  | t     | total: |
| helper    | works mainly on the drip pad and |    | otal: | 14     |
|           | load out area, placing and       | C  | 14    |        |
| CH; LH    | removing charge leads, opening   |    |       | 4 LH,  |
|           | and closing cylinder doors,      | D  | 4 LH, | 1/d    |
|           | retrieving leads, adjusting      |    | 1/d   |        |
|           | track switches, and banding and  |    |       | 5 CH,  |
|           | unbanding charges.               |    | 5 CH, | 1/d    |
|           |                                  |    | 1/d 5 |        |
|           |                                  |    | CH,   | 5 CH,  |
|           |                                  |    | 1/d   | 1/d    |
+-----------+----------------------------------+----+-------+--------+
| Checker   | Performed tasks of the loader    | C  | t     | total: |
|           | helper as well as inspecting     |    | otal: | 5      |
| CK        | treated lumber. Worker part time |    | 5     |        |
|           | in the treatment area.           |    |       | 5 CH,  |
|           |                                  |    | 5 CH, | 1/d    |
|           |                                  |    | 1/d   |        |
+-----------+----------------------------------+----+-------+--------+
| Test      | Takes core samples to test for   | A  | t     | total: |
| Borer/QC  | creosote penetration; may test   |    | otal: | 5      |
| Person    | creosote solution concentration  | C  | 9     |        |
|           | (site C); other QC laboratory    |    |       | 0      |
| TB        | duties. (These tasks performed   |    | 4,    |        |
|           | by CLO at site B)                |    | 1/day | 5,     |
|           |                                  |    |       | 1/day  |
|           |                                  |    | 5,    |        |
|           |                                  |    | 1/day |        |
+-----------+----------------------------------+----+-------+--------+
| Water     | Operates chemical/biological     | A  | t     | total: |
| Treatment | water recovery equipment (At     |    | otal: | 4      |
| System    | Site C, the tasks associated     | B  | 8     |        |
| Operator  | with this position were          |    |       | 0      |
|           | performed by the TB; position    |    | 4,    |        |
| WO        | not monitored at Site D)         |    | 1/day | 4,     |
|           |                                  |    |       | 1/day  |
|           |                                  |    | 4,    |        |
|           |                                  |    | 1/day |        |
+-----------+----------------------------------+----+-------+--------+
| Drip pad  | Steam-cleans drip pad area;      | C  | t     | total: |
| cleaner   | disposes of sludge and treated   |    | otal: | 4      |
|           | wood waste; other cleanup duties |    | 4     |        |
| DP        | in treatment and drip pad area.  |    |       | 4,     |
|           |                                  |    | 4,    | 1/day  |
|           |                                  |    | 1/day |        |
+-----------+----------------------------------+----+-------+--------+
| Total     |                                  |    | 108   | 88     |
+-----------+----------------------------------+----+-------+--------+

Site A is Florence, SC. Site B is Delson, Quebec. Site C is Denver, CO.
Site D is Somerville, Tx.

The worker exposure study on pressure treatment applications submitted
by the Creosote Council II to provide chemical-specific handler dermal
and inhalation exposure data in support of the re-registration of
pressure treatments of creosote (Creosote Council II, 2001, MRID
453234-01) is presented in Section 3.1. Other published studies for
creosote are presented in Section 4.0.

Because of the overall variability in the composition of creosote (e.g.,
over 100 known chemicals are components of creosote), it is difficult to
characterize its exact nature. Since neither the characterization of
airborne creosote nor the development of inhalation sampling methods is
specific for creosote, there exists a high variability in the creosote
inhalation data presented in the literature. Most of the studies
presented in the literature were conducted by industrial hygienists
using methods approved by the National Institute for Occupational Safety
and Health (NIOSH) and Occupational Safety and Health Administration
(OSHA) for polycyclic aromatic hydrocarbons (PAHs), phenols/creosols,
and the individual constituents of the PAHs (i.e., naphthalene,
phenanthrene, anthracene, etc). The Creosote Council study is the most
recent study presented on creosote exposure and presents both dermal and
inhalation exposure. This study provides the best available data on
worker exposure estimates and encompasses all of the worker activities
contributing to exposure. Nonetheless, other studies available in the
literature are also presented below in Section 4.0.

**3.1 Worker Exposure at Pressure Treatment Facilities**

The 2001 Creosote Council II study was conducted to determine the dermal
and inhalation exposure of workers exposed to creosote while performing
routine tasks related to pressure treatment of lumber, utility poles,
and railroad ties. The study was conducted at four typical commercial
treatment facilities in the U.S. and Canada, per the requirements of the
U.S. Environmental Protection Agency, Canada's Pesticide Management
Regulatory Agency (PMRA), and the California Department of Pesticide
Regulation. The four sites include older facilities from the 1940s as
well as more modern facilities with additional engineering controls.
Therefore, the exposure and risk estimates have been presented
separately for each site. The job functions monitored in the study are
presented in Table 3 above.

Previous drafts of the EPA's creosote assessment have defined the job
functions at pressure treatment facilities as either handlers or
postapplication. Since the job functions previously categorized as
handlers (treatment operators and assistants) perform many functions,
this creosote assessment does not highlight the job functions as being
either handler or postapplication. Workers in the study performed
typical tasks related to their job functions and were monitored during a
full work cycle beginning at 7 AM and ending at 3 PM.

1.  [**Pressure Treatment Process**]{.underline}

Pressure treatment is often required because of the resistance of wood
to deep penetration by preservatives. The pressure treatment process
begins when untreated wood is loaded onto rail/tram cars that are pushed
into the treating cylinder using locomotives, forklifts, or similar
equipment. The cylinder door is sealed via a pressure-tight door and the
operation remains a closed system during the entire treatment process.
Treating solutions are then pumped into the cylinder and the inside
pressure is raised. At the end of the treatment process, the excess
treating solution is pumped out of the treating cylinder and back to
storage for reuse. The cylinder is opened, and the rail/tram cars
holding the treated wood are pulled out of the cylinder using a
locomotive, forklift, or similar equipment.

The amount of creosote handled in a given day among pressure treatment
facilities depends on such factors as the size of the facility and the
number of treatment cylinders on site. In a given facility, the amount
of creosote handled per day varies depending on the wood conditioning
techniques used for a given charge, on the type of wood being treated,
and the type of product being produced (e.g., marine piling vs utility
poles).

According to information provided by industry sources (Krygsman, 1994),
wood pressure treatment of railroad ties in a retort may last anywhere
from 4 to 24 hours. A typical retort cylinder has a diameter of about 8
feet and a length of about 120 feet. About 16 rail/tram cars can be
placed in a retort at one time. The rail/tram cars usually are connected
together and are pushed in and out of the retort on railroad tracks
using a locomotive. Wood preservative is loaded into the wood pressure
treatment retort facilities from rail tank cars using hoses and metered
pumps. The wood preservative is stored in two or three holding tanks
that may be as large as 60,000 gallons. During the wood treatment
process the wood is sprayed under pressure in the enclosed retort. In
the retort, a "charge" of liquid preservative is pumped into the trams
and then later pumped out. After the wood preservative is pumped out,
the wood is dried through a vacuum treatment and the tram cars
containing wood (e.g. railroad ties) are then pulled out. Since the wood
in the tram cars is pulled by mechanical means there is very little
direct human contact with the exposed wood. Likely contact is through
dermal contact with equipment that was previously in the retort,
removing cables that separated layers of ties, dermal and inhalation
contact to vapors inside the retort before and after pressure treatment,
cleaning the retort, and inspecting wood pieces by coring the wood.

2.  **[Dermal Exposure Monitoring]{.underline}**

Since creosote is a complex mixture of over 100 chemicals including
phenols, creosol, and aromatic hydrocarbons, it is analytically
difficult and cost prohibitive to identify all of the chemicals in the
mix. In addition, creosote cannot be measured directly because of its
complex mixture. Dermal exposure to "total creosote" was estimated by
measuring the levels of 10 individual polynuclear aromatic hydrocarbon
(PNA) compounds. Each analyte was determined in each whole-body
dosimeter (WBD) and glove sample as if it represented total creosote.
The goal was to use these marker compounds to represent "total
creosote".

The creosote dermal exposure to each worker was determined using a WBD,
consisting of a 100% cotton thermal shirt and long pants. Each worker at
Sites A, C, or D wore his WBD under a fresh work uniform consisting of a
cotton long-sleeved work shirt and cotton work trousers (or one-piece
cotton coverall) provided by the test site. The workers at Site B were
not provided uniforms therefore; each worker wore a WBD under a fresh
lightweight cotton/polyester sweat shirt and pants purchased locally by
study personnel. The workers at all four sites wore a lightweight 100%
cotton glove dosimeter on each hand under his chemical-resistant or work
gloves, as appropriate. Each of these 10 analytes was determined for
each WBD and glove sample as if it represented total creosote. The
average of the analyte concentrations were used to estimate the level of
total creosote present in/on the individual sample.

**3.1.3 [Inhalation Exposure Monitoring]{.underline}**

Inhalation exposure for each worker was monitored by a personal air
sampling train. Inhalation exposure was estimated for 11 individual PNA
compounds as well as for benzene-soluble PNAs and related compounds
collectively known as coal tar pitch volatiles (CTPVs). The
Polytetrafluroethylene (PTFE) filter retained the CTPVs, while the PNAs
were retained in the XAD-2 resin tubes. Each worker wore a sampling
train consisting of a PTFE filter upstream from two in-line XAD-2
resin-filled air sampling tubes. However, there was no attempt by the
study sponsors to relate inhalation levels found for PNAs and CTPVs to
\"total creosote\" \-- a significant weakness with the study. Moreover,
there were analytical problems encountered with the CTPV samples and all
samples were non detect. Therefore, EPA did not rely on the CTPV
inhalation exposure monitoring results. Instead, naphthalene was used to
indicate inhalation exposure concerns.

Inhalation exposure monitoring at Site A was unsuccessful because a
single XAD-2 tube was used along with a non-solvent-resistant filter
cassette. Therefore, the sampling methodology was changed to include the
use of a second XAD-2 resin tube in the sampling train prior to sampling
at Sites B, C, and D. Inhalation exposure monitoring was performed
successfully at these sites. Each worker at Sites B, C, and D was
equipped with an air sampling train consisting of a PTFE filter in an
opaque, solvent-resistant plastic cassette connected upstream from two
in-line XAD-2 resin-filled air sampling tubes. The intake orifice of the
filter was placed in the worker's breathing zone, directed downward. Air
was pulled through the sampling train by a portable air sampling pump
attached to the worker's belt. The pump drew air through the sampling
tube at approximately 1 L/minute while the worker performed his tasks.
Pumps were calibrated immediately prior to and after each monitoring
period using a mass flow meter or bubble calibrator. The pumps were
turned on at the beginning of each work cycle and were left running
during restroom, coffee, or other short breaks, but were turned off or
set on "hold" during lunch breaks.

The pumps and samplers were removed from the worker during the lunch
break. At the conclusion of the lunch break, the pump and sampling train
were reinstalled and the pump restarted. All start and stop times for
breaks were recorded.

During each work cycle, start times and end times of each task performed
by the worker were recorded. Pump parameters during use were also
recorded. At the end of each work cycle, the pumps and sample trains
were collected. Each filter cassette and sampling tube were capped,
labeled, bagged, and placed on dry ice for shipment to USX Engineers and
Consultants, Inc. (UEC) for extraction and analysis. After the
collection of the air samples, the air sampling pump was re-calibrated.

**3.1.4** **[Exposure and Risk Characterization]{.underline}**

**[Estimated Dose:]{.underline}** The short-term dermal endpoint is
based on a maternal toxicological endpoint; therefore, a female body
weight of 60 kg was used for the dose calculation. The median adult
male/female body weight of 70 kg was used for the intermediate-term,
long-term, and cancer endpoints. Short-term, long-term, and cancer
endpoints are all based on oral administrations. Therefore, the 5
percent dermal absorption factor was used to estimate an absorbed dermal
dose for comparison to an orally administered dose in the toxicity
studies. The intermediate-term endpoint is based on a dermal toxicity
study, and therefore, no absorption factor was necessary. A route
specific inhalation assessment has been developed comparing the air
concentrations monitored for workers directly to the human equivalent
concentration (HEC) without the need for an extrapolated dose estimate.

The following equation was used to estimate the dermal dose. Because EPA
traditionally uses an adult body weight of 70 kg and female body weight
of 60 kg in its exposure assessments which is slightly different then
the 71.8 kg body weight used in the Creosote Council II exposure
assessment, the doses used in this assessment had to be normalized back
to daily dermal exposures. The normalization was performed by
multiplying the exposure dose times the 71.8 kg body weight.
Subsequently, the dermal exposure was converted into an absorbed and/or
potential dose using the 60 and 70 kg body weights.

-   Absorbed Daily Dermal Dose (mg/kg/day) = Dermal Exposure (mg/day) x
    Dermal Absorption (%) x (1/Body Weight)

The estimated absorbed dermal lifetime average daily dose (LADD) is
based on the following equation:

-   LADD~\[absorbed\]~ (mg/kg/day) = Absorbed dermal dose (mg/kg/day) x
    (250 days worked/365 days) x (35 years worked/70 year lifetime)

**[Estimated Non Cancer and Cancer Risks:]{.underline}** The
calculations of the daily dermal dose of creosote received by workers
were used to calculate the non cancer MOEs for the short-term,
intermediate-term, and long-term durations. The dermal MOEs were
calculated using (1) a NOAEL of 50 mg/kg/day for short-term exposure
with a target MOE of 100: (2) a NOAEL of 40 mg/kg/day for
intermediate-term exposures with a target MOE of 100; and, (3) a LOAEL
of 25 mg/kg/day for the long-term duration with a target MOE of 300.
Note: The intermediate-term dermal endpoint was selected from a dermal
toxicity study, and therefore, a dermal absorption factor was not
necessary to calculate the potential dose. The dermal and inhalation non
cancer MOE equations are as follows:

-   MOE ~\[dermal\]~ = NOAEL or LOAEL / Potential and/or Absorbed Dermal
    Dose

-   MOE ~\[inhalation\]~ = Human Equivalent Concentration (HEC) /
    Worker's air concentration

The cancer risk for creosote is based on the estimated absorbed dermal
lifetime average daily dose (LADD) multiplied by the cancer slope factor
for creosote dose as follows:

-   Cancer Risk = LADD~\[absorbed\]~ (mg/kg/day) x CSF of 6.28 x 10^-3^
    (mg/kg/day)^-1^

Using these equations, the worker exposure and risk estimates from the
Creosote Council's exposure study are presented in Table 4 (dermal
MOEs), Table 5 (inhalation MOEs), and Table 6 (dermal cancer risk).

**[Dermal MOEs (Table 4):]{.underline}** The results indicate the
short-term (ST) non cancer dermal MOEs do not trigger a risk concern
except for the treatment operator at site C where the dermal MOE is 68
and the target MOE is 100. The intermediate-term (IT) non cancer dermal
MOEs trigger risk concerns for 8 of the 24 scenarios presented. IT MOEs
range from 3 to 2700 and the target MOE is 100. The long-term (LT) non
cancer dermal MOEs trigger risk concerns for 3 of the 24 scenarios. LT
MOEs range from 34 to 34,000 and the target MOE is 300. IT risks being
greater than the LT risks is an anomaly. However, in the case of
creosote it is explainable because the IT toxicity endpoint is based on
a dermal study while the LT endpoint is based on an oral study (i.e.,
there are differences in routes of exposure and dosing levels between
the two studies).

+------+---+---+----------------+---------+---------+-----+----+-----+
| **T  |   |   |                |         |         |     |    |     |
| able |   |   |                |         |         |     |    |     |
| 4.   |   |   |                |         |         |     |    |     |
| Creo |   |   |                |         |         |     |    |     |
| sote |   |   |                |         |         |     |    |     |
| De   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| MOE  |   |   |                |         |         |     |    |     |
| s.** |   |   |                |         |         |     |    |     |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      |   |   |                | Po      | A       | Der |    |     |
|      |   |   |                | tential | bsorbed | mal |    |     |
| Job  | S | n | Site           |         |         | M   |    |     |
|      | i | = | Description    | dermal  | Dermal  | OEs |    |     |
|      | t |   |                | dose    | Dose    |     |    |     |
|      | e |   |                |         |         |     |    |     |
|      |   |   |                | (mg/    | (mg/    |     |    |     |
|      |   |   |                | kg/day) | kg/day) |     |    |     |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      |   |   |                |         |         | ST  | IT |     |
|      |   |   |                |         |         |     |    |     |
|      |   |   |                |         |         |     |    | LT  |
+------+---+---+----------------+---------+---------+-----+----+-----+
| TO   | A | 4 | 1940s; manual  | 0.414   | 0.021   | 2   | 97 | 1   |
|      |   |   |                |         |         | 415 |    | 208 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | B | 4 | 1983; Eng.     | 0.015   | 0.001   | 67  | 27 | 33  |
|      |   |   | Controls       |         |         | 568 | 03 | 784 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | C | 5 | 1940s          | 14.800  | 0.740   | 68  | 3  | 34  |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | D | 5 | 1970s;         | 0.132   | 0.007   | 7   | 3  | 3   |
|      |   |   | Automated      |         |         | 576 | 03 | 788 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| TA   | B | 4 | 1983; Eng.     | 0.025   | 0.001   | 40  | 16 | 20  |
|      |   |   | Controls       |         |         | 323 | 13 | 161 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| OU   | A | 4 | 1940s; manual  | 0.887   | 0.044   | 1   | 45 | 564 |
|      |   |   |                |         |         | 127 |    |     |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | D | 5 | 1970s;         | 0.938   | 0.047   | 1   | 43 | 533 |
|      |   |   | Automated      |         |         | 066 |    |     |
+------+---+---+----------------+---------+---------+-----+----+-----+
| CLO  | A | 4 | 1940s; manual  | 0.212   | 0.011   | 4   | 1  | 2   |
|      |   |   |                |         |         | 717 | 89 | 358 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | B | 4 | 1983; Eng.     | 0.089   | 0.004   | 11  | 4  | 5   |
|      |   |   | Controls       |         |         | 299 | 52 | 650 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | C | 5 | 1940s          | 2.120   | 0.106   | 472 | 19 | 236 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | D | 5 | 1970s;         | 0.117   | 0.006   | 8   | 3  | 4   |
|      |   |   | Automated      |         |         | 547 | 42 | 274 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| LLO  | B | 4 | 1983; Eng.     | 0.018   | 0.001   | 55  | 22 | 27  |
|      |   |   | Controls       |         |         | 249 | 10 | 624 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | C | 5 | 1940s          | 0.203   | 0.010   | 4   | 1  | 2   |
|      |   |   |                |         |         | 926 | 97 | 463 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | D | 1 | 1970s;         | 0.077   | 0.004   | 12  | 5  | 6   |
|      |   | 0 | Automated      |         |         | 953 | 18 | 477 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| LL   | D |   | 1970s;         | 0.244   | 0.012   | 4   | 1  | 2   |
| O(F) |   |   | Automated      |         |         | 098 | 64 | 049 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| LH   | B | 4 | 1983; Eng.     | 0.023   | 0.001   | 43  | 17 | 21  |
|      |   |   | Controls       |         |         | 860 | 54 | 930 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | C | 5 | 1940s          | 1.810   | 0.091   | 552 | 22 | 276 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | D | 5 | 1970s;         | 0.383   | 0.019   | 2   | 1  | 1   |
|      |   |   | Automated      |         |         | 611 | 04 | 305 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| CK   | C | 5 | 1940s          | 0.822   | 0.041   | 1   | 49 | 608 |
|      |   |   |                |         |         | 217 |    |     |
+------+---+---+----------------+---------+---------+-----+----+-----+
| TB   | A | 4 | 1940s; manual  | 0.112   | 0.006   | 8   | 3  | 4   |
|      |   |   |                |         |         | 929 | 57 | 464 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | C | 5 | 1940s          | 1.060   | 0.053   | 943 | 38 | 472 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| WO   | A | 4 | 1940s; manual  | 0.204   | 0.010   | 4   | 1  | 2   |
|      |   |   |                |         |         | 902 | 96 | 451 |
+------+---+---+----------------+---------+---------+-----+----+-----+
|      | B | 4 | 1983; Eng.     | 0.047   | 0.002   | 21  | 8  | 10  |
|      |   |   | Controls       |         |         | 322 | 53 | 661 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| DP   | C | 4 | 1940s          | 0.150   | 0.008   | 6   | 2  | 3   |
|      |   |   |                |         |         | 667 | 67 | 333 |
+------+---+---+----------------+---------+---------+-----+----+-----+
| Site |   |   |                |         |         |     |    |     |
| A,B  |   |   |                |         |         |     |    |     |
| ,C,D |   |   |                |         |         |     |    |     |
| indi |   |   |                |         |         |     |    |     |
| cate |   |   |                |         |         |     |    |     |
| dif  |   |   |                |         |         |     |    |     |
| fere |   |   |                |         |         |     |    |     |
| nces |   |   |                |         |         |     |    |     |
| in   |   |   |                |         |         |     |    |     |
| site |   |   |                |         |         |     |    |     |
| s    |   |   |                |         |         |     |    |     |
| etup |   |   |                |         |         |     |    |     |
| (e   |   |   |                |         |         |     |    |     |
| .g., |   |   |                |         |         |     |    |     |
| eng  |   |   |                |         |         |     |    |     |
| co   |   |   |                |         |         |     |    |     |
| ntro |   |   |                |         |         |     |    |     |
| ls). |   |   |                |         |         |     |    |     |
|      |   |   |                |         |         |     |    |     |
| De   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| e    |   |   |                |         |         |     |    |     |
| xpos |   |   |                |         |         |     |    |     |
| ures |   |   |                |         |         |     |    |     |
| are  |   |   |                |         |         |     |    |     |
| not  |   |   |                |         |         |     |    |     |
| no   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| ized |   |   |                |         |         |     |    |     |
| to   |   |   |                |         |         |     |    |     |
| the  |   |   |                |         |         |     |    |     |
| var  |   |   |                |         |         |     |    |     |
| ious |   |   |                |         |         |     |    |     |
| am   |   |   |                |         |         |     |    |     |
| ount |   |   |                |         |         |     |    |     |
| of   |   |   |                |         |         |     |    |     |
| wood |   |   |                |         |         |     |    |     |
| trea |   |   |                |         |         |     |    |     |
| ted. |   |   |                |         |         |     |    |     |
|      |   |   |                |         |         |     |    |     |
| Ar   |   |   |                |         |         |     |    |     |
| ithm |   |   |                |         |         |     |    |     |
| etic |   |   |                |         |         |     |    |     |
| mean |   |   |                |         |         |     |    |     |
| of   |   |   |                |         |         |     |    |     |
| the  |   |   |                |         |         |     |    |     |
| de   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| dose |   |   |                |         |         |     |    |     |
| from |   |   |                |         |         |     |    |     |
| T    |   |   |                |         |         |     |    |     |
| able |   |   |                |         |         |     |    |     |
| 9 of |   |   |                |         |         |     |    |     |
| the  |   |   |                |         |         |     |    |     |
| PMRA |   |   |                |         |         |     |    |     |
| wo   |   |   |                |         |         |     |    |     |
| rker |   |   |                |         |         |     |    |     |
| s    |   |   |                |         |         |     |    |     |
| tudy |   |   |                |         |         |     |    |     |
| rev  |   |   |                |         |         |     |    |     |
| iew. |   |   |                |         |         |     |    |     |
|      |   |   |                |         |         |     |    |     |
| Abs  |   |   |                |         |         |     |    |     |
| De   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| Dose |   |   |                |         |         |     |    |     |
| (mg  |   |   |                |         |         |     |    |     |
| /kg/ |   |   |                |         |         |     |    |     |
| day) |   |   |                |         |         |     |    |     |
| =    |   |   |                |         |         |     |    |     |
| de   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| dose |   |   |                |         |         |     |    |     |
| (mg  |   |   |                |         |         |     |    |     |
| /kg/ |   |   |                |         |         |     |    |     |
| day) |   |   |                |         |         |     |    |     |
| x 5% |   |   |                |         |         |     |    |     |
| de   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| ab   |   |   |                |         |         |     |    |     |
| sorp |   |   |                |         |         |     |    |     |
| tion |   |   |                |         |         |     |    |     |
|      |   |   |                |         |         |     |    |     |
| W    |   |   |                |         |         |     |    |     |
| here |   |   |                |         |         |     |    |     |
| ST   |   |   |                |         |         |     |    |     |
| N    |   |   |                |         |         |     |    |     |
| OAEL |   |   |                |         |         |     |    |     |
| is   |   |   |                |         |         |     |    |     |
| 50   |   |   |                |         |         |     |    |     |
| m    |   |   |                |         |         |     |    |     |
| g/kg |   |   |                |         |         |     |    |     |
| /day |   |   |                |         |         |     |    |     |
| (Ta  |   |   |                |         |         |     |    |     |
| rget |   |   |                |         |         |     |    |     |
| MOE  |   |   |                |         |         |     |    |     |
| =    |   |   |                |         |         |     |    |     |
| 100) |   |   |                |         |         |     |    |     |
| and  |   |   |                |         |         |     |    |     |
| LT   |   |   |                |         |         |     |    |     |
| L    |   |   |                |         |         |     |    |     |
| OAEL |   |   |                |         |         |     |    |     |
| is   |   |   |                |         |         |     |    |     |
| 25   |   |   |                |         |         |     |    |     |
| m    |   |   |                |         |         |     |    |     |
| g/kg |   |   |                |         |         |     |    |     |
| /day |   |   |                |         |         |     |    |     |
| (Ta  |   |   |                |         |         |     |    |     |
| rget |   |   |                |         |         |     |    |     |
| MOE  |   |   |                |         |         |     |    |     |
| =    |   |   |                |         |         |     |    |     |
| 3    |   |   |                |         |         |     |    |     |
| 00). |   |   |                |         |         |     |    |     |
|      |   |   |                |         |         |     |    |     |
| W    |   |   |                |         |         |     |    |     |
| here |   |   |                |         |         |     |    |     |
| IT   |   |   |                |         |         |     |    |     |
| N    |   |   |                |         |         |     |    |     |
| OAEL |   |   |                |         |         |     |    |     |
| is   |   |   |                |         |         |     |    |     |
| 40   |   |   |                |         |         |     |    |     |
| m    |   |   |                |         |         |     |    |     |
| g/kg |   |   |                |         |         |     |    |     |
| /day |   |   |                |         |         |     |    |     |
| (Ta  |   |   |                |         |         |     |    |     |
| rget |   |   |                |         |         |     |    |     |
| MOE  |   |   |                |         |         |     |    |     |
| =    |   |   |                |         |         |     |    |     |
| 100) |   |   |                |         |         |     |    |     |
| from |   |   |                |         |         |     |    |     |
| a    |   |   |                |         |         |     |    |     |
| de   |   |   |                |         |         |     |    |     |
| rmal |   |   |                |         |         |     |    |     |
| st   |   |   |                |         |         |     |    |     |
| udy. |   |   |                |         |         |     |    |     |
+------+---+---+----------------+---------+---------+-----+----+-----+

**[Inhalation MOEs (Table 5):]{.underline}** The non cancer inhalation
MOEs for worker exposure to naphthalene range from 23 to 1900 with a
target MOE of 300. Sixteen of the 19 inhalation MOEs presented exceed
the target MOE of 300, and therefore, are of concern. None of the
average air concentrations for the various job functions exceeded the
ACGIH TLV and OSHA PEL of 52 mg/m^3^.

+------+---+---+---------------+---------+----------+-------+-------+
| **T  |   |   |               |         |          |       |       |
| able |   |   |               |         |          |       |       |
| 5.   |   |   |               |         |          |       |       |
| In   |   |   |               |         |          |       |       |
| hala |   |   |               |         |          |       |       |
| tion |   |   |               |         |          |       |       |
| MOEs |   |   |               |         |          |       |       |
| for  |   |   |               |         |          |       |       |
| Na   |   |   |               |         |          |       |       |
| phth |   |   |               |         |          |       |       |
| alen |   |   |               |         |          |       |       |
| e**. |   |   |               |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
|      |   |   |               | Average | Average  |       | MOE   |
|      |   |   |               |         |          |       |       |
| Job  | S | n | Site          | Naphth  | Naphth   | \% of | (T    |
|      | i | = | Description   | (u      | (        | TLV   | arget |
|      | t |   |               | g/m^3^) | mg/m^3^) |       | 300)  |
|      | e |   |               |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| TO   | A | 4 | 1940s; manual | NA      | NA       | NA    | NA    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | B | 4 | 1983; Eng.    | 221     | 0.221    | 0.4   | 235   |
|      |   |   | Controls      |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
|      | C | 5 | 1940s         | 1320    | 1.32     | 2.5   | 39    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | D | 5 | 1970s;        | 802     | 0.802    | 1.5   | 65    |
|      |   |   | Automated     |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| TA   | B | 4 | 1983; Eng.    | 406     | 0.406    | 0.8   | 128   |
|      |   |   | Controls      |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| OU   | A | 4 | 1940s; manual | NA      | NA       | NA    | NA    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | D | 5 | 1970s;        | 925     | 0.925    | 1.8   | 56    |
|      |   |   | Automated     |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| CLO  | A | 4 | 1940s; manual | NA      | NA       | NA    | NA    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | B | 4 | 1983; Eng.    | 227     | 0.227    | 0.4   | 229   |
|      |   |   | Controls      |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
|      | C | 5 | 1940s         | 2033    | 2.033    | 3.9   | 26    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | D | 5 | 1970s;        | 574     | 0.574    | 1.1   | 91    |
|      |   |   | Automated     |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| LLO  | B | 4 | 1983; Eng.    | 27      | 0.027    | 0.1   | 1926  |
|      |   |   | Controls      |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
|      | C | 5 | 1940s         | 694     | 0.694    | 1.3   | 75    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | D | 1 | 1970s;        | 195     | 0.195    | 0.4   | 267   |
|      |   | 0 | Automated     |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| LL   | D |   | 1970s;        | 679     | 0.679    | 1.3   | 77    |
| O(F) |   |   | Automated     |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| LH   | B | 4 | 1983; Eng.    | 43      | 0.043    | 0.1   | 1209  |
|      |   |   | Controls      |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
|      | C | 5 | 1940s         | 1870    | 1.87     | 3.6   | 28    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | D | 5 | 1970s;        | 2251    | 2.251    | 4.3   | 23    |
|      |   |   | Automated     |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| CK   | C | 5 | 1940s         | 117     | 0.117    | 0.2   | 444   |
+------+---+---+---------------+---------+----------+-------+-------+
| TB   | A | 4 | 1940s; manual | NA      | NA       | NA    | NA    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | C | 5 | 1940s         | 853     | 0.853    | 1.6   | 61    |
+------+---+---+---------------+---------+----------+-------+-------+
| WO   | A | 4 | 1940s; manual | NA      | NA       | NA    | NA    |
+------+---+---+---------------+---------+----------+-------+-------+
|      | B | 4 | 1983; Eng.    | 917     | 0.917    | 1.8   | 57    |
|      |   |   | Controls      |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+
| DP   | C | 4 | 1940s         | 347     | 0.347    | 0.7   | 150   |
+------+---+---+---------------+---------+----------+-------+-------+
| Site |   |   |               |         |          |       |       |
| A,B  |   |   |               |         |          |       |       |
| ,C,D |   |   |               |         |          |       |       |
| indi |   |   |               |         |          |       |       |
| cate |   |   |               |         |          |       |       |
| dif  |   |   |               |         |          |       |       |
| fere |   |   |               |         |          |       |       |
| nces |   |   |               |         |          |       |       |
| in   |   |   |               |         |          |       |       |
| site |   |   |               |         |          |       |       |
| s    |   |   |               |         |          |       |       |
| etup |   |   |               |         |          |       |       |
| (e   |   |   |               |         |          |       |       |
| .g., |   |   |               |         |          |       |       |
| eng  |   |   |               |         |          |       |       |
| c    |   |   |               |         |          |       |       |
| ontr |   |   |               |         |          |       |       |
| ols) |   |   |               |         |          |       |       |
|      |   |   |               |         |          |       |       |
| TLV  |   |   |               |         |          |       |       |
| = 10 |   |   |               |         |          |       |       |
| ppm  |   |   |               |         |          |       |       |
| (52  |   |   |               |         |          |       |       |
| mg/m |   |   |               |         |          |       |       |
| ^3^) |   |   |               |         |          |       |       |
| STEL |   |   |               |         |          |       |       |
| 15   |   |   |               |         |          |       |       |
| ppm  |   |   |               |         |          |       |       |
| (79  |   |   |               |         |          |       |       |
| mg/m |   |   |               |         |          |       |       |
| ^3^) |   |   |               |         |          |       |       |
|      |   |   |               |         |          |       |       |
| mg/  |   |   |               |         |          |       |       |
| m^3^ |   |   |               |         |          |       |       |
| =    |   |   |               |         |          |       |       |
| u    |   |   |               |         |          |       |       |
| g/m3 |   |   |               |         |          |       |       |
| /    |   |   |               |         |          |       |       |
| 1000 |   |   |               |         |          |       |       |
|      |   |   |               |         |          |       |       |
| \%   |   |   |               |         |          |       |       |
| of   |   |   |               |         |          |       |       |
| TLV  |   |   |               |         |          |       |       |
| =    |   |   |               |         |          |       |       |
| (mg/ |   |   |               |         |          |       |       |
| m^3^ |   |   |               |         |          |       |       |
| /    |   |   |               |         |          |       |       |
| 52)  |   |   |               |         |          |       |       |
| x    |   |   |               |         |          |       |       |
| 100  |   |   |               |         |          |       |       |
|      |   |   |               |         |          |       |       |
| MOE  |   |   |               |         |          |       |       |
| =    |   |   |               |         |          |       |       |
| HEC  |   |   |               |         |          |       |       |
| /    |   |   |               |         |          |       |       |
| air  |   |   |               |         |          |       |       |
| c    |   |   |               |         |          |       |       |
| onc; |   |   |               |         |          |       |       |
| W    |   |   |               |         |          |       |       |
| here |   |   |               |         |          |       |       |
| HEC  |   |   |               |         |          |       |       |
| = 52 |   |   |               |         |          |       |       |
| mg/m |   |   |               |         |          |       |       |
| ^3^. |   |   |               |         |          |       |       |
+------+---+---+---------------+---------+----------+-------+-------+

**[Cancer Risks (Table 6):]{.underline}** All of the cancer risks exceed
the Agency's level of concern of 1 x 10^-6^ but only 4 of the risks
exceed 1 x 10^-4^ (i.e., risks range from 2.5 x 10^-5^ to 1.6 x 10^-6^).

+------+---+---+---------------+---------+----------+---------+------+
| **T  |   |   |               |         |          |         |      |
| able |   |   |               |         |          |         |      |
| 6.   |   |   |               |         |          |         |      |
| Creo |   |   |               |         |          |         |      |
| sote |   |   |               |         |          |         |      |
| De   |   |   |               |         |          |         |      |
| rmal |   |   |               |         |          |         |      |
| Ca   |   |   |               |         |          |         |      |
| ncer |   |   |               |         |          |         |      |
| Risk |   |   |               |         |          |         |      |
| s.** |   |   |               |         |          |         |      |
+------+---+---+---------------+---------+----------+---------+------+
|      |   |   |               | Po      |          |         |      |
|      |   |   |               | tential |          |         |      |
| Job  | S | n | Site          |         | Abs      | Abs     | Creo |
|      | i | = | Description   | dermal  | Dermal   | LADD    | sote |
|      | t |   |               | dose    | Dose     |         |      |
|      | e |   |               |         |          | (mg/    | Risk |
|      |   |   |               | (mg/    | (mg      | kg/day) |      |
|      |   |   |               | kg/day) | /kg/day) |         |      |
+------+---+---+---------------+---------+----------+---------+------+
| TO   | A | 4 | 1940s; manual | 0.414   | 0.0207   | 0.0071  | 4.5  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
|      | B | 4 | 1983; Eng.    | 0.0148  | 0.0007   | 0.0003  | 1.6  |
|      |   |   | Controls      |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
|      | C | 5 | 1940s         | 14.8    | 0.7400   | 0.2534  | 1.6  |
|      |   |   |               |         |          |         | E-03 |
+------+---+---+---------------+---------+----------+---------+------+
|      | D | 5 | 1970s;        | 0.132   | 0.0066   | 0.0023  | 1.4  |
|      |   |   | Automated     |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
| TA   | B | 4 | 1983; Eng.    | 0.0248  | 0.0012   | 0.0004  | 2.7  |
|      |   |   | Controls      |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
| OU   | A | 4 | 1940s; manual | 0.887   | 0.0444   | 0.0152  | 9.5  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
|      | D | 5 | 1970s;        | 0.938   | 0.0469   | 0.0161  | 1.0  |
|      |   |   | Automated     |         |          |         | E-04 |
+------+---+---+---------------+---------+----------+---------+------+
| CLO  | A | 4 | 1940s; manual | 0.212   | 0.0106   | 0.0036  | 2.3  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
|      | B | 4 | 1983; Eng.    | 0.0885  | 0.0044   | 0.0015  | 9.5  |
|      |   |   | Controls      |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
|      | C | 5 | 1940s         | 2.12    | 0.1060   | 0.0363  | 2.3  |
|      |   |   |               |         |          |         | E-04 |
+------+---+---+---------------+---------+----------+---------+------+
|      | D | 5 | 1970s;        | 0.117   | 0.0059   | 0.0020  | 1.3  |
|      |   |   | Automated     |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
| LLO  | B | 4 | 1983; Eng.    | 0.0181  | 0.0009   | 0.0003  | 1.9  |
|      |   |   | Controls      |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
|      | C | 5 | 1940s         | 0.203   | 0.0102   | 0.0035  | 2.2  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
|      | D | 1 | 1970s;        | 0.0772  | 0.0039   | 0.0013  | 8.3  |
|      |   | 0 | Automated     |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
| LL   | D |   | 1970s;        | 0.244   | 0.0122   | 0.0042  | 2.6  |
| O(F) |   |   | Automated     |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
| LH   | B | 4 | 1983; Eng.    | 0.0228  | 0.0011   | 0.0004  | 2.5  |
|      |   |   | Controls      |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
|      | C | 5 | 1940s         | 1.81    | 0.0905   | 0.0310  | 1.9  |
|      |   |   |               |         |          |         | E-04 |
+------+---+---+---------------+---------+----------+---------+------+
|      | D | 5 | 1970s;        | 0.383   | 0.0192   | 0.0066  | 4.1  |
|      |   |   | Automated     |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
| CK   | C | 5 | 1940s         | 0.822   | 0.0411   | 0.0141  | 8.8  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
| TB   | A | 4 | 1940s; manual | 0.112   | 0.0056   | 0.0019  | 1.2  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
|      | C | 5 | 1940s         | 1.06    | 0.0530   | 0.0182  | 1.1  |
|      |   |   |               |         |          |         | E-04 |
+------+---+---+---------------+---------+----------+---------+------+
| WO   | A | 4 | 1940s; manual | 0.204   | 0.0102   | 0.0035  | 2.2  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
|      | B | 4 | 1983; Eng.    | 0.0469  | 0.0023   | 0.0008  | 5.0  |
|      |   |   | Controls      |         |          |         | E-06 |
+------+---+---+---------------+---------+----------+---------+------+
| DP   | C | 4 | 1940s         | 0.15    | 0.0075   | 0.0026  | 1.6  |
|      |   |   |               |         |          |         | E-05 |
+------+---+---+---------------+---------+----------+---------+------+
| Site |   |   |               |         |          |         |      |
| A,B  |   |   |               |         |          |         |      |
| ,C,D |   |   |               |         |          |         |      |
| indi |   |   |               |         |          |         |      |
| cate |   |   |               |         |          |         |      |
| dif  |   |   |               |         |          |         |      |
| fere |   |   |               |         |          |         |      |
| nces |   |   |               |         |          |         |      |
| in   |   |   |               |         |          |         |      |
| site |   |   |               |         |          |         |      |
| s    |   |   |               |         |          |         |      |
| etup |   |   |               |         |          |         |      |
| (e   |   |   |               |         |          |         |      |
| .g., |   |   |               |         |          |         |      |
| eng  |   |   |               |         |          |         |      |
| c    |   |   |               |         |          |         |      |
| ontr |   |   |               |         |          |         |      |
| ols) |   |   |               |         |          |         |      |
|      |   |   |               |         |          |         |      |
| De   |   |   |               |         |          |         |      |
| rmal |   |   |               |         |          |         |      |
| expo |   |   |               |         |          |         |      |
| sure |   |   |               |         |          |         |      |
| not  |   |   |               |         |          |         |      |
| no   |   |   |               |         |          |         |      |
| rmal |   |   |               |         |          |         |      |
| ized |   |   |               |         |          |         |      |
| to   |   |   |               |         |          |         |      |
| var  |   |   |               |         |          |         |      |
| ious |   |   |               |         |          |         |      |
| amo  |   |   |               |         |          |         |      |
| unts |   |   |               |         |          |         |      |
| of   |   |   |               |         |          |         |      |
| wood |   |   |               |         |          |         |      |
| tre  |   |   |               |         |          |         |      |
| ated |   |   |               |         |          |         |      |
| per  |   |   |               |         |          |         |      |
| site |   |   |               |         |          |         |      |
|      |   |   |               |         |          |         |      |
| Ar   |   |   |               |         |          |         |      |
| ithm |   |   |               |         |          |         |      |
| etic |   |   |               |         |          |         |      |
| mean |   |   |               |         |          |         |      |
| from |   |   |               |         |          |         |      |
| T    |   |   |               |         |          |         |      |
| able |   |   |               |         |          |         |      |
| 9 of |   |   |               |         |          |         |      |
| the  |   |   |               |         |          |         |      |
| PMRA |   |   |               |         |          |         |      |
| rev  |   |   |               |         |          |         |      |
| iew. |   |   |               |         |          |         |      |
|      |   |   |               |         |          |         |      |
| Abs  |   |   |               |         |          |         |      |
| De   |   |   |               |         |          |         |      |
| rmal |   |   |               |         |          |         |      |
| Dose |   |   |               |         |          |         |      |
| (mg  |   |   |               |         |          |         |      |
| /kg/ |   |   |               |         |          |         |      |
| day) |   |   |               |         |          |         |      |
| =    |   |   |               |         |          |         |      |
| de   |   |   |               |         |          |         |      |
| rmal |   |   |               |         |          |         |      |
| dose |   |   |               |         |          |         |      |
| (mg  |   |   |               |         |          |         |      |
| /kg/ |   |   |               |         |          |         |      |
| day) |   |   |               |         |          |         |      |
| x 5% |   |   |               |         |          |         |      |
| de   |   |   |               |         |          |         |      |
| rmal |   |   |               |         |          |         |      |
| abs  |   |   |               |         |          |         |      |
|      |   |   |               |         |          |         |      |
| Creo |   |   |               |         |          |         |      |
| sote |   |   |               |         |          |         |      |
| Risk |   |   |               |         |          |         |      |
| =    |   |   |               |         |          |         |      |
| LADD |   |   |               |         |          |         |      |
| (mg  |   |   |               |         |          |         |      |
| /kg/ |   |   |               |         |          |         |      |
| day) |   |   |               |         |          |         |      |
| x    |   |   |               |         |          |         |      |
| creo |   |   |               |         |          |         |      |
| sote |   |   |               |         |          |         |      |
| oral |   |   |               |         |          |         |      |
| CSF  |   |   |               |         |          |         |      |
| of   |   |   |               |         |          |         |      |
| 6.2  |   |   |               |         |          |         |      |
| 8E-3 |   |   |               |         |          |         |      |
| (mg  |   |   |               |         |          |         |      |
| /kg/ |   |   |               |         |          |         |      |
| day) |   |   |               |         |          |         |      |
| ^-1^ |   |   |               |         |          |         |      |
+------+---+---+---------------+---------+----------+---------+------+

**3.2** **Post-application Exposures and Risks**

There is the potential for post-application exposures to creosote.
Potential post-application exposure may occur as a result of creosote
treated wood in commercial, industrial, and residential settings. There
is the potential for contact with creosote treated wood for occupational
workers who install railroad ties and poles. Railroad workers may become
exposed during the mechanical and manual installation of pressure
treated railroad crossties as well as during inspection procedures
(ATSDR, 1990). Pole installers may also contact creosote treated wood
while attaching fittings on telephone poles, installing new telephone
poles, conducting ground line treatment of telephone poles, and
maintaining and repairing existing telephone poles (ATSDR, 1990). No
dermal exposure data were available for these scenarios. Mechanical
installation and/or the use of appropriate PPE are recommended to reduce
exposure/contact with creosote treated wood.

There is no creosote product registered for residential uses; however,
EPA recognizes that some creosote-treated wood such as railroad ties are
used outdoors in home landscaping. Based on the label directions of
creosote products, EPA considers such uses of creosote-treated wood to
be illegal under FIFRA 12(a) (2) (G). For creosote-treated wood that is
misused in residential landscaping, the potential dermal and incidental
oral exposures to outdoor landscape timbers are expected to be episodic
in nature. During the public comment period on this risk assessment, EPA
received comments recommending wipe studies to assess dermal and
incidental oral exposure to children contacting creosote treated
landscape ties. EPA has considered the need for surface residue data on
recycled, creosote-treated railroad ties once they are removed from
service. A similar type of assessment was conducted for CCA-treated
lumber using the SHEDS model. The CCA SHEDS assessment was developed for
arsenic exposure to treated dimensional lumber. The CCA SHEDS model
assesses children that are exposed to play sets and decks specifically
built for contact by children. Compared to play sets EPA expects there
would be considerably less contact and less frequent contact by children
with landscape ties and on wood not used for specific children's play
structures. Based on this type of comparison, the fact that creosote
used in residential settings is a misuse of the product, and creosote is
less potent of a carcinogen then arsenic, EPA does not believe a
SHEDS-type of an assessment for creosote treated ties used as landscape
timbers is warranted at this time.

**4.0 Summary of Literature Exposure Studies**

Additional creosote exposure studies in the literature are summarized
below and presented in Table 7. Some of the air concentrations in Table
7 from these published studies exceed the ACGIH TLV and PEL of 0.2
mg/m^3^ for CTPV. The results of the air concentrations reported in the
literature support the results of the Creosote Council's worker exposure
study indicating that exposure to creosote should be reduced.

Todd and Timbie **(NIOSH 1980)** estimated occupational exposures of
workers to creosote in a railroad tie treatment plant in Somerville,
Texas. Petroleum oil/creosote solutions of 70/30 and 50/50 were used
respectively to treat the cross ties and bridge timbers in the plant.
The concentrations of creosote (i.e., coal-tar pitch volatiles; CTPV) in
personal air samples over a two-day monitoring period ranged from 0.002
to 1.211 mg/m^3^.

Another NIOSH study **(NIOSH 1981a)** of occupational exposure to
creosote at a wood-treatment facility in Tacoma, Washington reported
CTPV concentrations in personal air samples ranging from less than
0.0004 to 0.112 mg/m^3^ with the highest concentration found at the end
of the treatment process when the cylinder was opened. NIOSH also
reported creosote exposures of dock builders ranging from zero to 0.059
mg/m^3^ based on cyclohexane extractable fraction of CTPV **(NIOSH;
1981b)**.

Studies conducted by **Markel et al. (1977) and SRI (1993)** indicated
that particulate polycyclic organic materials (PPOM) was within 0.1
mg/m^3^, the NIOSH permissible level for CTPV, when estimating
occupational exposure to creosote in wood treatment plants. The
concentrations of naphthalene, methylnaphthalene, and acenaphthene (the
only components in the vapor-phase fractions that could be reliably
measured) ranged from 0.54 to 2.0 mg/m^3^. Benzene-soluble particulates
(PPOM) ranged from 0.02 to 0.10 mg/m^3^.

**Hiekkila et al. (1987)** conducted an occupational study in Finland
estimating workers' exposure to creosote in the creosote impregnation
plants and when they were handling the impregnated wood. The average
vapor concentrations (naphthalene being the major component) ranged from
0.5 to 71 mg/m^3^ in the impregnation plants; while the vapor
concentrations ranged from 0.1 to 11 mg/m^3^ in the handling of
impregnated wood. Most of the airborne contaminants in workers'
breathing zones were in the vapor phase; the proportion of particulate
polycyclic aromatic hydrocarbons (PAHs) to total concentration of vapors
was less than 0.5 to 3.7 percent.

**Rotard and Mailahn (1987)** reported high levels of carcinogenic PAHs,
such as benzo\[a\]pyrene, benzo\[b\]-fluoranthene, and
benzo\[j\]fluoranthene, and cocarcinogenic PAHs in samples of wooden
sleepers (railroad cross ties) installed in playgrounds.

**Borack et. al. 2002** conducted air sampling and biological monitoring
of 36 workers at a wood treatment plant where railroad ties were treated
with creosote. There were 18 low exposure workers who worked as
secretaries or clerical staff, 13 moderate exposure workers who
transported cured ties to the shipment yard and 3 high exposure workers
who worked in the retort building and handled ties immediately after
creosote application. Air sampling was conducted with a filters and
adsorbent tubes both of which were analyzed for benzene soluble PAHs.
Six filter samples had detectable levels of particulate PAHs and the
highest level was 0.33 ug/m^3^ for pyrene. Thirty two of the tube
samples had detectable levels of vapor phase PAHs but levels were
generally low. The highest levels were for pyrene and naphthalene
measured in the high exposure group and ranged from 1.5 to 2.5 ug/m^3^
for pyrene and 210 ug/m^3^ to 330 ug/m^3^ for naphthalene. Biomonitoring
was performed using urinary 1-hydroxypropene and the results suggested
that more than 90% of the measured 1-hydroxypropene could be attributed
to dermal exposure.

**Elovarra et.al. 1995** conducted air sampling and biological
monitoring of six workers (1 impregnator, 2 assistant operators, 1 lorry
driver and 2 tie platers) at an impregnation plant in Russia where
railroad ties were treated with creosote. The air sampling was conducted
for five consecutive days using filters and adsorbent tubes. The filters
were analyzed for nine PAHS other than naphthalene and the tubes were
analyzed for naphthalene. The results for the filter samples ranged from
1.23 to 13.74 ug/m^3^ with a GM of 4.77 ug/m^3^ and an AM of 5.7
ug/m^3^. The naphthalene results of the tube samples ranged from 370 to
4200 ug/m^3^ with a GM of 1536 ug/m^3^ and an AM of 1254 ug/m^3^.
Biomonitoring was performed using urinary 1-hydroxypropene and indicated
that dermal uptake was much greater than inhalation uptake.

**Flickinger and Lawrence, 1982** data was cited in Wong and Harris,
2005 which is an epidemiological study of creosote workers at 11 plants
in the United States. This data indicates that 95 percent of the workers
at the woodtreating plants were exposed to no more than 0.14 mg/m^3^
CTPV-BSF. In terms of specific jobs, the typical time-weighted average
of treating operators at the participating plants ranged from 0.04 to
0.11 mg/m^3^ CTPV-BSF with most measurements centered on 0.05 or 0.06
mg/m^3^ CTPV. Because of the limited nature of the data, however, the
epidemiology study was based on job/exposure categories rather than the
data.

**Heikkila et. al. 1997** conducted air sampling and biological
monitoring of six workers at an impregnation plant where railroad ties
were treated with creosote. The air sampling was conducted for one
workweek and samples were analyzed for ten PAHs and naphthalene. The
mean exposures were 1.5 mg/m^3^ for naphthalene vapor, 5.9 ug/m^3^ for
particulate PAHs and 1.4 ug/m^3^ for PAHs with 4-6 aromatic rings.
Biomonitoring was conducted in conjunction with the air sampling and
indicated that airborne naphthalene correlated fairly well with urinary
1-napthol (r = 0.745). It was also determined, however, that urinary
1-naphthol alone is not a suitable marker for inhalatory or cutaneous
exposure to PAH originating from creosote.

**Baker and Fannick, 1980** surveyed worker exposures to coal tar pitch
volatiles during a NIOSH health hazard evaluation on October 14, 1980 at
the New York Port Authority. The evaluation was requested by a union
representative on behalf of six workers engaged in pile driving creosote
preserved wood logs for a dock underpinning. Personal and area air
samples were collected. Breathing zone CPTV concentrations ranged up to
0.06 mg/m^3^ and area CPTV concentrations ranged up to 0.02 mg/m^3^.
These concentrations were below the NIOSH recommended limit of 0.1
mg/m^3^, however weather conditions on the sampling day probably caused
substantial reductions in exposure. The authors concluded that on
typical days workers may be exposed to significant amounts of CPTV.

**Unwin et. al. 2006** conducted air sampling and biological monitoring
of eleven workers at a timber impregnation plant as part of a larger
study of PAH occupational exposure in the U.K that was funded by the
British Health Executive. The workers included 2 pole fabricators, 2
pole loaders, 1 timber loader, 2 creosote plant operators, 1 unchainer,
2 labourers and 1 QC inspector. The air sampling was conducted for one
day using an IOM fitted with glass fiber filters and followed by an
XAD-2 adsorbent tube. The air samples were analyzed for 17 PAHs
including napthalene. The results expressed as total PAH ranged from
29.9 to 1913 ug/m^3^ with a mean of 835 ug/m^3^. The PAH profile was
dominated by naphthalene and the results for total 3-6 ring PAH and BaP
were much lower with mean values of 0.05 ug/m^3^ for 3-6 ring PAH and
0.01 ug/m^3^ for BaP. Biomonitoring was performed using urinary
1-hydroxypropene and indicated that the creosote workers had the highest
exposure among the 25 workplaces surveyed.

**Table 7. Summary of Occupational Inhalation Exposure Studies of
Creosote**

+--------------+----------------+---------------------+---+---------------+
| **Study**    | **Sett         | **Components        |   | **Co          |
|              | ing/Subjects** | Reported            |   | ncentration** |
|              |                | (Analyzed)**        |   |               |
|              |                |                     |   | (mg/m^3^)     |
+==============+================+=====================+===+===============+
| NIOSH; 1980  | railroad tie   | coal-tar pitch      |   | 0.002-1.211   |
| (Todd &      | treatment      | volatiles (CTPV)    |   |               |
| Timbie)      | plant          |                     |   |               |
+--------------+----------------+---------------------+---+---------------+
| NIOSH; 1981a | wood treatment | CTPV                |   | 0.0004-0.112  |
| (Todd &      | facility       |                     |   |               |
| Timbie)      |                |                     |   |               |
+--------------+----------------+---------------------+---+---------------+
| NIOSH; 1981b | dock builder   | CTPV (cyclohexane   |   | 0-0.059       |
| (Baker &     |                | extractables)       |   |               |
| Fannick)     |                |                     |   |               |
+--------------+----------------+---------------------+---+---------------+
| Markel et    | wood treatment | polycyclic organic  |   | \<0.1         |
| al. (1977)   | facility       | materials (PPOM)    |   |               |
| and SRI      |                |                     |   |               |
| (1993)       |                |                     |   |               |
+--------------+----------------+---------------------+---+---------------+
| Hiekkila et  | creosote       | average total vapor |   | 0.5-71        |
| al. (1987)   | impregnation   | (naphthalene being  |   |               |
|              | plant;         | the major           |   |               |
|              |                | component)          |   |               |
+--------------+----------------+---------------------+---+---------------+
| Hiekkila et  | handling       | average total vapor |   | 0.1-11        |
| al. (1987)   | impregnated    | (naphthalene being  |   |               |
|              | wood           | the major           |   |               |
|              |                | component)          |   |               |
+--------------+----------------+---------------------+---+---------------+
| Elovaara et. | Railroad Tie   | 10 PAHs include     | 0 |               |
| al., 1995    | impregnation   | Naphthalene         | . |               |
|              | plant in       |                     | 4 |               |
|              | Russia/six     |                     | 0 |               |
|              | workers, 5     |                     | t |               |
|              | days           |                     | o |               |
|              |                |                     | 4 |               |
|              |                |                     | . |               |
|              |                |                     | 2 |               |
|              |                |                     | N |               |
|              |                |                     | a |               |
|              |                |                     | p |               |
|              |                |                     | h |               |
|              |                |                     | t |               |
|              |                |                     | h |               |
|              |                |                     | a |               |
|              |                |                     | l |               |
|              |                |                     | e |               |
|              |                |                     | n |               |
|              |                |                     | e |               |
+--------------+----------------+---------------------+---+---------------+
| Borak,       | Railroad Tie   | Benzene Soluble     | 0 |               |
| et.al., 2002 | impregnation   | Fraction/16 PAHS    | . |               |
|              | plant /34      |                     | 2 |               |
|              | workers, all   |                     | 1 |               |
|              | jobs including |                     | - |               |
|              | office/1 days  |                     | - |               |
|              |                |                     | 0 |               |
|              |                |                     | . |               |
|              |                |                     | 3 |               |
|              |                |                     | 3 |               |
|              |                |                     | N |               |
|              |                |                     | a |               |
|              |                |                     | p |               |
|              |                |                     | h |               |
|              |                |                     | t |               |
|              |                |                     | h |               |
|              |                |                     | a |               |
|              |                |                     | l |               |
|              |                |                     | e |               |
|              |                |                     | n |               |
|              |                |                     | e |               |
|              |                |                     |   |               |
|              |                |                     | 0 |               |
|              |                |                     | . |               |
|              |                |                     | 0 |               |
|              |                |                     | 1 |               |
|              |                |                     | 5 |               |
|              |                |                     | t |               |
|              |                |                     | o |               |
|              |                |                     | 0 |               |
|              |                |                     | . |               |
|              |                |                     | 0 |               |
|              |                |                     | 0 |               |
|              |                |                     | 2 |               |
|              |                |                     | 5 |               |
|              |                |                     | p |               |
|              |                |                     | y |               |
|              |                |                     | r |               |
|              |                |                     | e |               |
|              |                |                     | n |               |
|              |                |                     | e |               |
+--------------+----------------+---------------------+---+---------------+
| Flicker and  | Wood           | CTPV-BSF            | 0 |               |
| Lawrence,    | Preserving     |                     | . |               |
| 1982         | Ind            |                     | 0 |               |
|              | ustry/Treating |                     | 4 |               |
| Cited in     | Operators      |                     | - |               |
| Wong and     |                |                     | - |               |
| Harris, 2005 |                |                     | 0 |               |
|              |                |                     | . |               |
|              |                |                     | 1 |               |
|              |                |                     | 1 |               |
+--------------+----------------+---------------------+---+---------------+
| Heikkila et. | Railroad tie   | Naphthalene and 10  | 1 |               |
| al. 1997     | impregnation   | PAHs                | . |               |
|              | plant/six      |                     | 5 |               |
|              | workers/one    |                     | N |               |
|              | week           |                     | a |               |
|              |                |                     | p |               |
|              |                |                     | h |               |
|              |                |                     | t |               |
|              |                |                     | h |               |
|              |                |                     | a |               |
|              |                |                     | l |               |
|              |                |                     | e |               |
|              |                |                     | n |               |
|              |                |                     | e |               |
|              |                |                     | ( |               |
|              |                |                     | m |               |
|              |                |                     | e |               |
|              |                |                     | a |               |
|              |                |                     | n |               |
|              |                |                     | ) |               |
|              |                |                     |   |               |
|              |                |                     | 0 |               |
|              |                |                     | . |               |
|              |                |                     | 0 |               |
|              |                |                     | 0 |               |
|              |                |                     | 5 |               |
|              |                |                     | 9 |               |
|              |                |                     | P |               |
|              |                |                     | A |               |
|              |                |                     | H |               |
|              |                |                     | ( |               |
|              |                |                     | m |               |
|              |                |                     | e |               |
|              |                |                     | a |               |
|              |                |                     | n |               |
|              |                |                     | ) |               |
+--------------+----------------+---------------------+---+---------------+
| Baker and    | Pile Driving   | CPTV                | U |               |
| Fannick,     | Creosote       |                     | p |               |
| 1980         | Dock/New York  |                     | t |               |
|              | Port           |                     | o |               |
|              | Authority/six  |                     | 0 |               |
|              | workers/one    |                     | . |               |
|              | day            |                     | 0 |               |
|              |                |                     | 6 |               |
|              |                |                     | ( |               |
|              |                |                     | n |               |
|              |                |                     | = |               |
|              |                |                     | 6 |               |
|              |                |                     | ) |               |
+--------------+----------------+---------------------+---+---------------+
| *Unwin et.   | *Timber        | *Total PAH          | * |               |
| al. 2006*    | im             | (Primarily          | 0 |               |
|              | pregnation/UK* | naphthalene)*       | . |               |
|              |                |                     | 0 |               |
|              |                |                     | 3 |               |
|              |                |                     | 0 |               |
|              |                |                     | - |               |
|              |                |                     | - |               |
|              |                |                     | 1 |               |
|              |                |                     | . |               |
|              |                |                     | 9 |               |
|              |                |                     | ( |               |
|              |                |                     | n |               |
|              |                |                     | = |               |
|              |                |                     | 1 |               |
|              |                |                     | 1 |               |
|              |                |                     | ) |               |
|              |                |                     | * |               |
+--------------+----------------+---------------------+---+---------------+

**5.0 Uncertainties and Limitations**

This section summarizes the uncertainties and data limitations in the
creosote assessment.

-   The amount of product applied and the amount of active ingredient
    handled by each worker was not calculated because the creosote was
    applied in a closed system which recovered and retained excess
    treatment solution from the wood and treatment vessel while sealed.
    The amount of wood treated at the 4 sites is believed to be
    representative of the industry.

-   The number of field fortification samples collected at the sites was
    less than the required number to satisfy Series 875 guidelines.
    According to the guidelines, there should be at least one
    fortification sample per worker per monitoring period (8 hour shift)
    per fortification level (three levels) for each matrix and at least
    one field blank per worker per monitoring period for each matrix.
    There were more workers monitored than there were field
    fortifications and field blank samples collected.

-   The overall inhalation field fortification percent recoveries for
    the coal tar pitch volatiles (CTPVS) were poor. The overall recovery
    for Site B was 57%. The overall recoveries for Sites C and D were
    51% and 57%, respectively. The analytical method for quantifying
    CTPVs in the creosote study was inadequate and only one filter had a
    detectable level. Therefore, inhalation exposure to CTPVs was not
    determined. Instead, risk concerns are indicated using the results
    of the naphthalene inhalation samples.

-   There were some dermal fortification levels with extremely high
    recoveries for WBD's and some with unacceptable low recoveries for
    gloves. As an example, for a 60 μg/sample "total creosote"
    fortification for Site B, the recoveries for the WBD's were as high
    as 150% and recoveries for the gloves as low as 52.3%. There were
    measurable amounts of total creosote found in each of the control
    samples prepared at each facility.

-   The study sponsors made no attempt to relate inhalation levels found
    for PNAs and CTPVs to \"total creosote\" \-- a significant weakness
    with the study.

**6.0** **References**

Agency for Toxic Substances and Disease Registry (ATSDR, 1990).
Toxicological Profile for Creosote. U.S. Public Health Service. February
16, 1990.

Agency for Toxic Substances and Disease Registry (ATSDR, 1995).
Toxicological Profile for Creosote. U.S. Public Health Service.

Baker and Fannick, 1980. HHE-80-238-931 New York Port Authority,
Brooklyn New York, NIOSH 1980.

Borak et. al. 2002. Biological Versus Ambient Exposure Monitoring of
Creosote Facility Workers, JOEM, Vol. 44, No. 4, April 2002.

Butala J. H. February, 1999. Creosote Council II memorandum with
attachment to Nader Elkassabany, U.S. Environmental Protection Agency,
Antimicrobial Division.

Creosote Council II, 1998. "Assessment of Potential Creosote Inhalation
and Dermal Exposure Associated with Pressure- Treatment of Wood with
Creosote." Submitted by John H. Buttala, Creosote Council II. Field work
by George M. Singer, Ph.D, American Agricultural Services Inc.
Analytical work by David A. Winkler, EN-CAS Laboratories.

Creosote Council II, 2001. "Assessment of Potential Creosote Inhalation
and Dermal Exposure Associated with Pressure Treatment of Wood with
Creosote." Submitted by John H. Butala, Creosote Council II. Field work
by Mark G. Bookbinder, Ph.D, c/o American Agricultural Services Inc.
Analytical work by Bert Clayton, EN-CAS Laboratories and Stephanie
Guilyard, USX Engineers and Consultants. MRID 453234-01.

Elovaara et. al. 1995. Significance of Dermal and Respiratory Uptake in
Creosote Workers: Exposure to Polycyclic Aromatic Hydrocarbons and
Urinary Excretion of 1-hydroxypyrene, Finnish Institute of Occupational
Safety and Health, Occup. Environ Med 1995: 52:196-203.

Flickinger and Lawrence, 1982. Occupational Health Experience in the
Wood Preserving Industry. Koppers Company, Inc. MRID 447595-02.

Flickinger and Lawrence, 1982. Occupational Health Experience in the
Wood-Preserving Industry, American Wood-Preservers Association, 1982
(Cited in Wong and Harris).

Heikkila PR, Hameila M, Pyy L, et al. 1987. Exposure to Creosote in the
Impregnation and Handling of Impregnated Wood. Scand J Work Environ
Health 13:431‑437.

Heikkila et.al. 1997. Urinary 1-naphthol Excretion in the Assessment of
Exposure to Creosote in an Impregnation Facility, Scand J. Work Environ
Health, 1997.

Krygsman, Adrian 1994. "Wood Preservation. An Overview of Biocide Use
and Application." NIOSH (1980a). Industrial Hygiene Report,
Comprehensive Survey of Wood Preservative Treatment Facility at Santa Fe
Centralized Tie Plant, Somerville, Texas. National Institute for
Occupational Safety and Health, Division of Surveillance, Hazard
Evaluations and Field Studies, Cincinnati, OH. (by Todd AS & Timbie CY).
NTIS PB83‑133892.

Markel, H.L.; Ligo, R.N.; Lucas, J.B. 1977. Health Hazard
Evaluation/Toxicity Determination Report 75-117-372. Koppers Company,
Inc. North Little Rock, Arkansas.

NIOSH (1980). Industrial Hygiene Report, Comprehensive Survey of Wood
Preservative Treatment Facility at Santa Fe Centralized Tie Plant,
Sommerville, Texas. National Institute of Occupational Safety and
Health, Division of Surveillance Hazard Evaluations and Field Studies,
Cincinnati, OH. (by Todd AS and Timbie CY). NTIS PB83-133892.

NIOSH (1981a). Industrial Hygiene Report, Comprehensive Survey of Wood
Preservative Treatment Facility at Cascade Pole Company, McFarland
Cascade, Tacoma, Washington. National Institute for Occupational Safety
and Health, Division of Surveillance, Hazard Evaluations and Field
Studies, Cincinnati, OH. (by Todd AS and Timbie CY). NTIS PB82‑174160.

NIOSH (1981b). Health Hazard Evaluation: New York Port Authority,
Brooklyn, New York. U.S. Department of Health and Human Services,
National Institute for Occupational Safety and Health, Cincinnati, OH.
(by Baker D & Fannick N). HHE 80‑238‑931.

Rotard W, Mailahn W (1987). Gas Chromatographic-Mass Spectrometric
Analysis of Creosotes Extracted from Wooden Sleepers Installed in
Playgrounds. Anal. Chem. 59:65-69.

SRI. 1993. Directory of chemical producers: United States of America.
SRI International, Menlo Park, CA.

The Environmental Degradation of Creosote, 1998.

http://inweh1.uwaterloo.ca/biol447new/assignments/creo2.html.

United States Environmental Protection Agency (USEPA), 1984. "Wood
Preservative Pesticides: Creosote, Pentachlorophenol, Inorganic
Arsenicals. Position Document 4." Registration Division. Office of
Pesticides and Toxic Substances. Washington, DC. July, 1994.

United States Environmental Protection Agency (USEPA), 1997a. Standard
Operating Procedures for Residential Exposure Assessments. December,
1997. Residential Exposure Assessment Work Group, U.S. Environmental
Protection Agency.

United States Environmental Protection Agency (USEPA), 1997b. Exposure
Factors Handbook. Volume 1. Office of Research and Development.
Washington, DC. EPA/600/P-95/002Fa.

United States Environmental Protection Agency (USEPA), 1998a. Route to
Route Extrapolations. Memorandum from John E. Whalan EPA/OPP/HED to
Margaret Stasikowski, Director EPA/OPP/HED.

United States Environmental Protection Agency (USEPA), 1998b. Creosote
LUIS Database. USEPA Report Run Date 3/09/98.

United States Environmental Protection Agency (USEPA), 1998c.
International Harmonization Position Paper. Antimicrobial Exposure
Databases. An Overview of the NAFTA Member Agencies Regulatory Authority
Over Antimicrobial Pesticides And An Evaluation of Existing Databases
Used in Antimicrobial Exposure Assessments. Prepared by Antimicrobial
Division. Office of Pesticide Programs.

United States Environmental Protection Agency (USEPA), 1998d. Inhalation
Risk Characterizations and the Aggregate Risk Index (ARI). Memorandum
from John E. Whalan, EPA/OPP/HED, to Margaret Stasikowski, Director,
EPA/OPP/HED.

United States Environmental Protection Agency (USEPA), 1998e. Integrated
Risk Information System (IRIS) database.

United States Environmental Protection Agency (USEPA), 1999. Creosote -
Report of the Hazard Identification Review Committee, April 1, 1999.

United States Environmental Protection Agency (USEPA), 2001. Assessment
of Potential Creosote Inhalation and Dermal Exposure Associated with
Pressure-Treatment of Wood with Creosote. Office of Pesticides and Toxic
Substances, January 30, 2001.

Unwin et. al. 2006. An Assessment of Occupational Exposure to Polycyclic
Aromatic Hydrocarbons in the UK, Ann. Occupational Hygiene, Vol. 50, No.
4, pp 395-403, 2006.

Wong and Harris, 2005. Retrospective Cohort Mortality Study and Nested
Case Control Study of Workers Exposed to Creosote at 11 Wood-Treating
Plants in the United States, JOEM, Vol. 47, no. 7, July 2005.