-------
EPA-600/8 34-001A
February 1984
External Review Draft
DRAFT
Do not dte or quote
HEALTH ASSESSMENT DOCUMENT
FOR
HEXACHLOROCYCLOPENTADIENE
Notice
This document 1s a preliminary draft. It has not been
formally released by EPA and should not at this stage be
construed to represent Agency policy. It 1s being circu-
lated for comment on Us technical accuracy and policy Im-
plications.
U.S. ENVIRONMENTAL PROTECTION AGI-NCY
Office of Research and Development
Environmental Criteria and Assessment Office
Cincinnati, Ohio 45268
Project Manager: David J. Relsman
U.S. E^v'rTsn'-Tif'M Fraction Agency
Re;.••-.-< '
230 So. . • - ii C'.--.,Jt
Chicago, iiiincls 60604
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DISCLAIMER
This report Is an Internal draft for review purposes only and does not
constitute Agency policy. Mention of trade names or commercial products does
not constitute endorsement or recommendation for use. Reports submitted by
Velslcol Chemical Corporation to the U.S. EPA and reviewed 1n this document
are for research purposes only. Permission for any other use of these studies
should be directed to that company.
NOTE
For Information concerning this document, please contact the project
manager, David J. Relsman (513/684-7572) of the Environmental Criteria and
Assessment Office, Cincinnati, OH 45268.
Dl.r. ..
' -election Agency
11
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PREFACE
The Office of Health and Environmental Assessment of the Office of
Research and Development has prepared this Health Assessment Document (HAD)
at the request of the Office of A1r Quality Planning and Standards. Hexa-
chlorocyclopentadlene (HEX) 1s an Intermediate In the pesticide manufactur-
ing process and 1s currently being studied by the Environmental Protection
Agency (EPA) to determine 1f 1t should be regulated as a hazardous air
pollutant under the Clean Air Act.
The scientific literature has been searched and Inventoried, key studies
have been reviewed and evaluated and summaries and conclusions have been
directed at Identifying the health effects from exposure to HEX. At several
stages 1n the HAD development process, the HEX document has been reviewed
for scientific and technical accuracy. These peer reviews have been by
scientists from Inside and outside the EPA. Observed effect levels and
dose-response relationships are discussed where appropriate 1n order to
Identify the critical effect and to place adverse health responses 1n
perspective with observed environmental effects.
111
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Document Development
David J. Relsman
Jerry F. Stara
Project Manager
Office Director
Contributors
F1n1s Cavender
W. Bruce Pelrano
Randall J.F. Bruins
Sheila Rosenthal
Dharm V. Singh
Charles H. Nauman
S. Que Hee
Ralph Northrop
Carol Glasgow
Richard Hertzberg
The MHre Corporation
ECAO-CIN
ECAO-CIN
OHEA-REAG
OHEA-CAG
OHEA-EAG
University of Cincinnati
OTS
01S
ECAO-CIN
Reviewers
Franklin M1nk
William Pepelko
Michael Oourson
Erma Durden
Linda Erdrelch
ECAO-CIN
ECAO-CIN
ECAO-CIN
ECAO-CIN
ECAO-CIN
Technical Services Staff
Document Production
ECAO-CIN
1v
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Co-chairmen:
Hexachlorocyclopentadlene Peer Review Panel Members
June 29, 1983 Cincinnati, Ohio
Jerry F. Stara, ECAO-CIN
David J. Relsman, ECAO-CIN
Finis Cavender, Mitre
James WUhey
Frederick Coulston
Mary Anne Zanetos
C. Ralph Buncher
Fumlo Matsumura
Wyman Dorough
Joseph Borzelleca
Jack L. Egle
Shane Que Hee
Charles H. Nauman
Randall J.F. Bruins
W. Bruce Pelrano
Linda S. Erdrelch
Richard C. Hertzberg
Ralph Northrop
John Komlnsky
Alfred A. Levin
Mildred S. Root
James Grutsch
Members
Food Directorate, Canada
Coulston International
Battelle Memorial Institute
University of Cincinnati
Michigan State University
University of Kentucky
Medical College of Virginia
Medical College of Virginia
University of Cincinnati
U.S. EPA, OHEA
U.S. EPA, ECAO-CIN
U.S. EPA, ECAO-CIN
U.S. EPA, ECAO-CIN
U.S. EPA, ECAO-CIN
U.S. EPA, OTS
U.S. DHHS, NIOSH
Velslcol Chemical Corp.
Velslcol Chemical Corp.
Velslcol Chemical Corp.
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TABLE OF CONTENTS
Page
1. INTRODUCTION
2. SUMMARY, CONCLUSIONS AND RESEARCH NEEDS
2.1.
2.2.
2.3.
SUMMARY
2.1.1. Properties, Production and Uses
2.1.2. Sources, Environmental Levels, Transport and Fate .
2.1.3. Aquatic Life, Vegetation and Wildlife
2.1.4. Pharmacoklnetlcs, Toxicology, Exposure and
Health Effects
CONCLUSIONS
RESEARCH NEEDS
3. PHYSICAL AND CHEMICAL PROPERTIES/ANALYTICAL METHODOLOGY
3.1.
3.2.
3.3.
3.4.
SYNONYMS, TRADE NAMES AND IDENTIFICATION
PHYSICAL AND CHEMICAL PROPERTIES
3.2.1. Physical Properties
3.2.2. Chemical Properties
ANALYTICAL METHODOLOGY
3.3.1. A1r
3.3.2. Water
3.3.3. Soil
BIOLOGICAL MEDIA
3.4.1. Sampling
3.4.2. Analysis
4. PRODUCTION, USE, SOURCES AND AMBIENT LEVELS
4.1.
4.2.
4.3.
4.4.
4.5.
4.6.
PRODUCTION
USE
SOURCES
AMBIENT LEVELS
4.4.1. Air
4.4.2. Water
4.4.3. Food
4.4.4. Soil
RELATIVE SOURCE CONTRIBUTIONS
SUMMARY AND CONCLUSIONS
1-1
2-1
2-1
2-1
2-1
2-2
2-3
2-4
2-5
3-1
3-1
3-1
3-1
3-4
3-4
3-4
3-8
3-11
3-12
3-12
3-13
4-1
4-1
4-1
4-1
4-2
4-4
4-4
4-7
4-7
4-7
4-7
V1
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Page
ENVIRONMENTAL FATE AND TRANSPORT 5-1
5.1. FATE 5-1
5.1.1. Air 5-1
5.1.2. Water 5-2
5.1.3. Soil 5-12
5.2. TRANSPORT 5-18
5.2.1. Air 5-18
5.2.2. Water 5-19
5.2.3. Soil 5-22
5.3. BIOCONCENTRATION/BIOACCUMULATION 5-23
5.4. SUMMARY AND CONCLUSIONS 5-29
ECOLOGICAL EFFECTS 6-1
6.1. EFFECTS ON AQUATIC ORGANISMS 6-1
6.1.1. Freshwater Aquatic Life 6-1
6.1.2. Marine and Estuarlne Aquatic Life 6-4
6.2. EFFECTS ON OTHER ECOSYSTEMS 6-8
6.3. EFFECTS ON TERRESTRIAL VEGETATION 6-10
6.4. EFFECTS ON WILDLIFE 6-10
6.5. SUMMARY 6-10
TOXICOLOGY AND HEALTH EFFECTS 7-1
7.1. PHARMACOKINETICS 7-1
7.1.1. Absorption, Distribution, Metabolism and
Excretion 7-1
7.1.2. Summary 7-9
7.2. MAMMALIAN TOXICOLOGY 7-10
7.2.1. Acute Tox1c1ty 7-10
7.2.2. Subchronlc Tox1c1ty 7-14
7.2.3. Chronic Toxldty 7-20
7.3. MUTAGENICITY 7-22
7.3.1. Mutagenldty 7-22
7.3.2. Summary 7-25
7.4. CARCINOGENICITY 7-25
7.4.1. In vivo Cardnogenldty 7-25
7.4.2. In vitro Carc1nogen1c1ty 7-25
7.4.3. Summary 7-26
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Page
7.5. TERATOGENIC AND REPRODUCTIVE EFFECTS 7-26
7.5.1. TeratogenlcHy 7-26
7.5.2. Reproductive Effects 7-27
7.5.3. Summary 7-27
7.6. HUMAN EXPOSURE AND HEALTH EFFECTS 7-28
7.6.1. Human Exposure 7-28
7.6.2. Health Effects 7-28
7.6.3. Summary 7-41
8. OVERVIEW 8-1
8.1. EFFECTS OF MAJOR CONCERN 8-1
8.1.1. Principal Effects and Target Organs 8-1
8.1.2. Animal Toxldty Studies Most Useful for Hazard
Assessments 8-2
8.2. FACTORS INFLUENCING HEALTH HAZARD ASSESSMENT 8-6
8.2.1. Exposure 8-6
8.2.2. Lowest Observed Effect Level 8-6
8.2.3. Carc1nogen1c1ty 8-7
8.3. REGULATIONS AND STANDARDS 8-8
8.3.1. Occupational Standards 8-8
8.3.2. Transportation Regulations 8-8
8.3.3. Solid Waste Regulations 8-9
8.3.4. Food Tolerances 8-9
8.3.5. Water Regulations 8-10
8.3.6. A1r Regulations 8-10
8.3.7. Other Regulations 8-10
9. REFERENCES 9-1
APPENDIX: Toxlclty Table for Hexachlorocyclopentadlene A-l
-------
LIST OF TABLES
No. Title Page
3-1 Identity of Hexachlorocyclopentadlene 3-2
3-2 Physical Properties of Hexachlorocyclopentadlene 3-3
3-3 Characteristics of the Porapak T Collection System 3-9
3-4 Optimized GC Analytical Procedure for HEX 3-10
4-1 HEX Content 1n the Effluent Stream of the Memphis North
Sewage Treatment Plant, 1982 4-3
4-2 Area A1r Samples Collected at the Memphis North Treatment
Plant, 1978 4-5
4-3 Concentrations of Selected Organic Compounds 1n Influent
Wastewater at Memphis North Treatment Plant, 1978 4-6
5-1 Summary of Constants Used 1n the Exposure Analysis
Modeling System (EXAMS) at 25°C In Water 5-6
5-2 Summary of Results of Computer Simulation of the Fate and
Transport of Hexachlorocyclopentadlene 1n Four Typical
Aquatic Environments 5-7
5-3 M1crob1al Degradation of HEX During 14-Day Exposure 1n a
Test Medium 5-17
5-4 Relative Distribution of HEX and Its Degradation Products . . 5-27
6-1 Acute Toxlclty Data for Freshwater Species Exposed to HEX . . 6-2
6-2 Acute Toxlclty Data on Marine Organisms Exposed to HEX. . . . 6-6
6-3 Effects of 28 Days Exposure of Mysld Shrimp, Mys1dops1s
bahla. to HEX 6-7
7-1 Disposition of Radioactivity from 14C-HEX 1n Rats Dosed
by Various Routes 7-5
7-2 Fate of Radiocarbon Following Oral, Inhalation and
Intravenous Exposure to 14C-HEX In Rats 7-6
7-3 Distribution of HEX Equivalents 1n Tissues and Excreta
of Rats 72 Hours After Oral, Inhalation and Intravenous
Exposure to 14C-HEX 7-7
1x
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No. Title Page
7-4 Acute ToxIcHy of HEX 7-11
7-5 Subchronlc ToxIcHy of HEX 7-16
7-6 lexicological Parameters for Mice and Rats Administered
HEX for 91 Days 7-17
7-7 Memphis HEX Monitoring Summary 7-29
7-8 Marshall HEX Monitoring Summary 7-31
7-9 Symptoms of 145 Wastewater Treatment Plant Employees
Exposed to HEX 7-34
7-10 Abnormalities for 18 of 97 Cleanup Workers at the Morris
Forman Treatment Plant 7-36
7-11 Overview of Individual Exposure - Symptomatology Corre-
lations at the Morris Forman Treatment Plant 7-37
7-12 Hepatic Profile Comparison of Hardeman County: Exposed
Group (November 1978) and Control Group 7-39
8-1 Oral ToxIcHy Data for Threshold Estimates 8-3
8-2 Inhalation ToxIcHy Data for Threshold Estimates 8-4
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LIST OF FIGURES
No. Title Page
1 Structure Diagram of Hexachlorocyclopentadlene x1
3-1 Synthesis of Chlorinated Pesticides from
Hexachlorocyclopentadlene 3-5
5-1 Proposed Pathway of Aqueous HEX Phototransformatlon 5-5
5-2 Rate of Blodegradatlon of 14C-HEX to 14C02 5-11
5-3 Persistence of Nonpolar 14C when 14C-HEX 1s Applied to
Unaltered and Altered Soils 5-15
x1
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FIGURE 1
Structure Diagram of Hexachlorocyclopentadlene
xll
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1. INTRODUCTION
Hexachlorocyclopentadlene (HEX) 1s an unsaturated. highly reactive,
chlorinated cyclic hydrocarbon of low water solubility and relatively high
vapor pressure. Hexachlorocyclopentadlene 1s a chemical Intermediate 1n the
manufacture of chlorinated pesticides and flame retardants with essentially
no end uses of Us own. The major source of environmental contamination by
HEX 1s the aqueous discharge from production facilities, with small concen-
trations present as Impurities 1n commercial products made from 1t. Thus,
HEX 1s not frequently found 1n the environment and, even when present, It 1s
rapidly degraded. In view of this and recent controls on environmental
emissions, environmental exposure to HEX Is extremely low. However, from
time to time, Isolated Instances such as the sewer system disposal of HEX
wastes (an Illegal act) In 1977 1n Louisville, KY, and the cleanup of a
large waste disposal site 1n Michigan In 1983, have brought this chemical to
the forefront of environmental news.
Hexachlorocyclopentadlene 1s not readily absorbed because It is highly
reactive, especially with the contents of the gastrointestinal (GI) tract.
HEX 1s moderately toxic when given orally and has been estimated to be 100
times more toxic when Inhaled. The data base for chronic toxlclty of HEX 1s
very limited. A chronic Inhalation bloassay 1s scheduled by the National
Toxicology Program (NTP) and may provide data regarding any carcinogenic
potential of HEX.
Several literature reviews on the health and environmental effects of
HEX are available and Include the following: Equitable Environmental
Health, Inc. (1976), National Academy of Sciences (NAS, 1977), Bell et al.
(1978) and U.S. EPA (1980c). Although each of these reports 1s different 1n
scope and emphasis, a large amount of the scientific knowledge about HEX 1s
1808A 1-1 01/19/84
-------
Included In these documents. To avoid unnecessary duplication, previously
reviewed material found In these documents will not be considered at great
length, except when It Impinges directly upon present critical considera-
tions. The Information presented 1n this document 1s up-to-date through
1983, and contains a critical evaluation of some data which were not avail-
able at the publication time of the previously mentioned documents.
1808A 1-2 01/05/84
-------
2. SUMMARY, CONCLUSIONS AND RESEARCH NEEDS
2.1. SUMMARY
2.1.1. Properties, Production and Uses. Hexachlorocyclopentadlene (HEX,
C-56) 1s a dense pale-yellow or greenish-yellow, nonflammable liquid with a
unique, pungent odor. HEX has a molecular weight of 272.77, low water solu-
bility and a relatively high vapor pressure. It 1s highly reactive and
undergoes addition, substitution and D1els-Alder reactions.
Hexachlorocyclopentadlene Is produced by only one company 1n the United
States, Velslcol Chemical Corporation. Production data are considered
proprietary; however, 1t has been estimated that between 8 and 15 million
pounds/year are produced. HEX has been used as an Intermediate 1n the pro-
duction of many pesticides; however, this use has been limited by restric-
tions on the production of certain organochlorlne pesticides. HEX 1s also
used 1n the manufacture of flame retardants, resins and dyes.
2.1.2. Sources, Environmental Levels, Transport and Fate. HEX 1s
released Into the environment during Us manufacture and during the manufac-
ture of products requiring HEX. HEX can enter the environment as an Impur-
ity and contaminant 1n some of the products using HEX as an Intermediate.
There are only limited monitoring data available concerning the environment-
al levels of HEX. The available Information suggests that HEX will be
present mainly 1n the aquatic compartment and associated with bottom sedi-
ments and organic matter.
The fate and transport of HEX In the atmosphere, considering available
Information, suggests that the compound has a tropospherlc residence time
(the time required for the concentration to be reduced by 1/e) of only ~5
hours. However, atmospheric transport of HEX from an area of stored wastes
and from wet wells during treatment of Industrial wastes has been demon-
strated.
1809A 2-1 01/05/84
-------
In water, HEX may undergo photolysis, hydrolysis and blodegradatlon. In
shallow water, HEX has a photolytlc half-life of <1 hour. In deeper water
where photolysis 1s precluded, the hydrolytlc half-life of HEX 1s several
days, while blodegradatlon 1s predicted to occur more slowly. HEX 1s known
to volatilize from water, but this 1s Influenced by turbulence and adsorp-
tion on to sediments.
HEX should be relatively Immobile In soil based on Us low water solu-
bility. Volatilization, which 1s likely to occur primarily at the soil
surface, 1s Inversely related to the organic matter levels and water-holding
capacity of the soil. Chemical hydrolysis and mlcroblal metabolism are
expected to reduce levels of HEX 1n soils.
The b1oconcentrat1on/b1oaccumulat1on/b1omagn1f1cat1on potential of HEX
appears to be substantial based on Us high log P value. B1oaccumulat1on
factors derived from a short-term model ecosystem study appear to Indicate a
moderate accumulation potential for algae, snails, mosquito larvae, and
mosquito fish. However, the compound did not blomagnlfy substantially from
algae to snails or from mosquito larvae to fish. In addition, steady-state
bloconcentratlon factors, measured 1n 30 to 32-day flow-through exposures,
were only 29 and <11 1n fish exposed to constant HEX levels of 20.9 yg/9.
and 9.1 ppb, respectively.
2.1.3. Aquatic Life, Vegetation and Wildlife. Low concentrations of HEX
have been shown to be toxic to aquatic life. Lethality In acute (48 to
96-hour) exposures has been observed In both freshwater and saltwater crus-
taceans and fish at nominal concentrations of 32-180 pg/9. In static
exposure systems 1n which the water Is not renewed during the test. In the
only studies using flowing water, measured HEX concentrations, Identical
1809A 2-2 01/05/84
-------
96-hour LCrn values of 7 yq/H were obtained for a freshwater fish and
bu
a saltwater shrimp. Chronic tests with the latter two species showed
adverse effects at levels as low as 7.3 and 0.70 yg/fc, respectively.
Seven-day static tests with marine algae showed median reduction of
growth (EC™) at nominal concentrations ranging from 3.5-100 yg/H,
depending on the species.
In aqueous media, HEX Is toxic to many microorganisms at nominal concen-
trations of 0.2-10 mg/i, or levels substantially higher than those needed
to kill most aquatic animals or plants. Some microorganisms are able to
withstand HEX exposures as high as 1000 mg/fc. HEX appears to be less
toxic to microorganisms in soil than 1n aquatic media, probably due to
adsorption of HEX on the soil matrix.
Sufficient Information Is not available to determine the effects of HEX
exposure on terrestrial vegetation or wildlife, although data from labora-
tory studies summarized 1n the following sections could be used to estimate
effects on mammals 1n the wild.
2.1.4. Pharmacoklnetlcs, Toxicology, Exposure and Health Effects. HEX 1s
not readily absorbed because 1t Is highly reactive, especially with the
contents of the gastrointestinal tract. HEX 1s considered a primary Irri-
tant, extremely toxic by Inhalation, and moderately toxic by oral 1nges-
tlon. Radlolabeled 14C-HEX 1s retained by the kidneys and liver of ani-
mals after oral or Inhalation dosing; after Inhalation, the trachea and
lungs also retain radlolabeled material. Absorbed HEX 1s metabolized and
rapidly excreted, predominantly 1n the urine and feces with <1% of the HEX
found 1n expired air. Following Inhalation or Intravenous Injection no
unchanged HEX Is excreted, and the fecal and urinary metabolites have been
Isolated, but not Identified.
1809A 2-3 01/05/84
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The acute Inhalation lethal concentration (LC5Q) of 1.6 and 3.5 ppm 1n
male and female rats, respectively, has been demonstrated. Although there
are some Interspedes differences between guinea pigs, rabbits, rats and
mice, HEX vapors are toxic to all species tested. HEX appears most toxic
when administered via Inhalation, with oral and then dermal administration
being less toxic routes. Systemic effects of acute exposure Include degen-
erative changes In the lungs, liver, kidneys and adrenal glands.
Subchronlc oral dosing of rats (38 mg/kg/day) and mice (75 mg/kg/day)
' '„ ••_ 6': • ,,,-., ^ -
for 91 days produced nephrosls and Inflammation and hyperplasla of the fore-
stomach. No overt signs were noted when mice or rats were exposed by In-
halation at 0.2 ppm of HEX (6 hours/day, 5 days/week) for 14 weeks. How-
ever, Inhalation exposure of rats at 0.5 ppm for 30 weeks caused degenera-
tive changes 1n the liver, respiratory tract and kidneys. In. vitro test
results from three species have not shown HEX to be a mutagen. HEX was also
Inactive 1n the mouse dominant lethal assay.
Limited data are available on the effects of exposure In humans. Expo-
sure to HEX vapors causes severe Irritation of the eyes, nose, throat and
lungs. Dermal contact causes skin Irritation and chemical burns. Informa-
tion on oral exposures 1n humans has not been located.
2.2. CONCLUSIONS
This document presents the current scientific data base for hexachloro-
cyclopentadlene. During the course of review, two other chemicals were
Identified as having toxic effects similar to HEX, but very IHtle research
on their health effects could be located 1n the scientific literature.
These two chemicals, hexachloronorbornadlene (HEX-BCH) and heptachloronor-
bornene (HEX-VCL), along with HEX were all found In the Influent wastewater
of a treatment plant with a nearby pesticide manufacturing plant. The toxic
Interactions of these chemicals are not known.
1809A 2-4 01/19/84
-------
The data base 1s neither extensive nor adequate for assessing the
cardnogenlcHy of HEX. The National Toxicology Program (NTP) has recently
completed a subchronlc animal study and will begin a lifetime animal Inhala-
tion bloassay using both rats and mice 1n 1984. Two epidemlologic studies
*.: .• I 4
were cited In the literature; however, no Increased Incidences of neoplasms
at any site were reported which could be related to HEX. These studies were
Insensitive because of the short duration of follow-up. A final judgment of
cardnogenlcHy will have to be deferred until the results of the NTP bio-
assay are available. According to the International Agency for Research on
Cancer (IARC) criteria, HEX Is classified as Group 3.
There are Inadequate data to assess the long-term effects of low-level
and/or acute Intermittent HEX exposure 1n humans.
2.3. RESEARCH NEEDS
An unresolved Issue at the peer review workshop concerned the matter 1n
which external factors Influence the vapor pressure of HEX. Consider-
able discussion resulted 1n the recommendation that a study of vapor
pressure should be Included as a priority Hem 1n future research.
The greatest deficiency 1n the HEX data 1s the absence of a thorough
metabolism study In which the metabolites are Isolated and Identified.
Continuous monitoring and study of groups exposed to continuous low
levels of HEX 1s warranted. Monitoring data are needed to derive esti-
mates of exposure, especially for those areas 1n close proximity to
production and formulation facilities. Continue and expand epidemic-
logic studies.
Further studies to determine the ultimate fate of HEX 1n the environment
are needed.
Teratogenlclty studies should be conducted using various routes of expo-
sure, with emphasis on the Inhalation route.
1809A 2-5 01/19/84
-------
3. PHYSICAL AND CHEMICAL PROPERTIES/ANALYTICAL METHODOLOGY
3.1. SYNONYMS. TRADE NAMES AND IDENTIFICATION
Hexachlorocyclopentadlene (HEX) Is the most commonly used name for the
compound that Is designated 1,2,3,4,5,5'-hexachloro-l,3-cyclopentadlene by
the International Union of Pure and Applied Chemistry (IUPAC) system.
Table 3-1 cites the IUPAC name and synonyms, Identification numbers and
molecular and structural formulas of HEX.
3.2. PHYSICAL AND CHEMICAL PROPERTIES
3.2.1. Physical Properties. Hexachlorocyclopentadlene 1s a nonflammable
liquid with a characteristic pungent, musty odor; the pure compound 1s light
lemon-yellow. Impure HEX may have a greenish tinge (Stevens, 1979). It has
a molecular weight of 272.79 and Us molecular formula 1s CrCl,. Hexa-
b o
chlorocyclopentadlene (98%) 1s a dense liquid (sp. gr. 1.7019 at 15°C) with
low solubility In water (0.805-2.1 mg/8. at 25°C). A detailed 11st of
physical properties Is presented 1n Table 3-2. The compound Is strongly
adsorbed by soil colloids. It volatilizes rapidly from water (Atallah et
al., 1980). According to the Handbook of Chemistry and Physics (Weast and
Astle, 1980), the ultraviolet visible x m, In heptane 1s 323 nm with a
max
log (molar absorptivity) of 3.2. This absorption band reaches Into the vis-
ible spectrum, as evidenced by the yellow color of HEX. Facile carbon-
chlorine bond scission might be expected 1n sunlight or under fluorescent
light. The IR spectrum has characteristic absorptions at 6.2, 8.1, 8.4,
8.8, 12.4, 14.1 and 14.7 ym. The mass spectrum of HEX shows a weak molec-
ular Ion (M) at H/e 270, but a very Intense (M-35) 1on making this latter
1on suitable for sensitive specific 1on monitoring.
1810A 3-1 01/06/84
-------
TABLE 3-1
Identity of Hexachlorocyclopentadlene
Identifying Characteristic
Name/Number/Structure
IUPAC Name:
Trade Names:
Synonyms:
CAS Number
CIS Accession Number:
Molecular Formula:
Molecular Structure:
1,2,3,4,5,5'-Hexachloro-l,3-cyclopentad1ene
C56; HRS 1655; Graphlox
Hexachlorocyclopentadlene
Perchiorocyclopentad1ene
HEX
HCPD
HCCP
HCCPD
C-56
HRS 1655
Graphlox
77-47-4
7800117
C5C16
nn
r\* |
Cl
Cl
Cl Cl
1818A
3-2
6/8/83
-------
TABLE 3-2
Physical Properties of Hexachlorocyclopentadlene
Property
Value/Description
Reference
Molecular Weight:
Physical Form (25°C)
Odor:
Electronic Absorption Max-
imum [(In 50% acetonl-
trlie-water); nm]
Solubility (25°C)
Water (mg/fc):
Organic Solvents:
Vapor Density (air = 1)
Vapor Pressure
(mmHg, °C):
Specific Gravity:
Melting Point (°C):
Boiling Point (°C):
Octanol/Water Partition
Coefficient (log P)
(measured):
(estimated):
Latent Heat of Vaporiza-
tion
Henry's Law Constant
(atm-mVmole)
272.79 Stevens, 1979
Pale yellow liquid Hawley, 1977; Irish, 1963
Pungent Hawley, 1977; Irish, 1963
322
2.1
0.805
1.8 (28°C)
M1sc1ble (Hexane)
9.4.
0.08 (25°C)
0.975 (62°C)
1.717 (15°C)
1.710 (20°C)
1.7019 (25°C)
-9.6
-11.34
239
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3.2.2. Chemical Properties. Commercial HEX has various purities depend-
ing upon the route of synthesis. HEX made by chlorlnatlon of cyclopenta-
dlene by alkaline hypochloMte at 40°C. followed by fractional distillation,
1s only 75% pure, and contains many lower chlorinated cyclopentadlenes.
Purities >90% have been obtained by thermal dechlorlnatlon of octachloro-
cyclopentene at 470~480°C (Stevens, 1979).
If moisture 1s excluded, HEX can be stored without harming the product
or Us containers. Storage containers should not have Iron 1n their Inner
linings (Stevens, 1979).
Hexachlorocyclopentadlene 1s a highly reactive dlene that readily under-
goes addition and substitution reactions and also participates 1n D1els-
Alder reactions (Ungnade and McBee, 1958). The products of the D1els-Alder
reaction of HEX with a compound containing a non-conjugated double bond are
generally 1:1 adducts containing a hexachlorob1cyclo(2,2,l)heptene struc-
ture; the monoene derived part of the adduct 1s nearly always 1n the endo-
posHlon, rather than the exo-pos1t1on (Stevens, 1979). Figure 3-1 Illus-
trates synthetic pathways to various chlorinated pesticides for which HEX 1s
a precursor. Flame retardant chemicals for which HEX 1s a precursor Include
chlorendlc add, chlorendlc anhydride and Dechlorane Plus (Stevens, 1979).
Two excellent early reviews of the chemistry of HEX were- published by
Roberts (1958) and Ungnade and McBee (1958). Look (1974) reviewed the for-
mation of HEX adducts of aromatic compounds and the by-products of the Dlels
Alder reaction.
3.3. ANALYTICAL METHODOLOGY
3.3.1. A1r.
3.3.1.1. SAMPLING — The techniques used to collect samples of HEX
vapor In air Involve the adsorption and concentration of the vapors 1n
liquid-filled 1mp1ngers or solid sorbent-packed cartridges.
1810A 3-4 01/19/84
-------
ISODHIN
ENORIN
CD
O
I
in
o
o
^
co
HEPTACHIOK
ENDOSULFAN
EPOXIDATION
PE» ACIDS
AlClj, 5.02 OR FUUEKS
£A«TH IN CCI< 0*
O* SOjCI;' SfNZOYL
P6ROXIDE IN
Cj-HYD«OCAMONS =-^ CMICTINATION
0 > HEXACHLOROCYCIOPENTADIENE
OICYClOPENTA
OlENt
•CHjCI
ffNTAC
KFPONE
FIGURE 3-1
Synthesis of Chlorinated Cyclodlene Pesticides from Hexachlorocyclopentadlene
Source: Adapted from Lawless et al., 1972; Bell et al.f 1978
-------
WhHmore et al. (1977) pumped airborne vapors through a miniature glass
Implnger tube containing hexane or benzene and through a solid sorbent
packed (Chromasorb* 102) tube. Sampling efficiency was 97% with hexane
and -100X with benzene. The sampling efficiency for the solid sorbent tube
was -100X. The sensitivity of the liquid 1mp1nger system was found to be <1
ppb 1n ambient air.
Komlnsky and Wlsseman (1978) collected HEX vapor on Chromasorb® 102
(20/40 mesh) sorbent previously cleaned by extraction with 1:1 acetone/
methanol. The extraction removed Interfering compounds. The sorbent was
packed Into a front 100-mg and a back 50-mg section separated by a 2 mm
polyurethane plug 1n a glass tube, 7 cm long and 4 mm 1.d. The samplers
were collected using battery powered vacuum pumps operating at 0.05 or 0.20
l/m1nute. HEX was desorbed with carbon dlsulflde (68% efficiency) and
analyzed by gas chromatography-flame 1on1zat1on detection (Neumelster and
KuMmo, 1978).
In studying the pyrolysls products of Endosulfan, Chopra et al. (1978)
collected the vapors of Endosulfan-treated tobacco smoke 1n a cold trap con-
taining pentane cooled to 0 and -80°C. The pentane extract was then pre-
pared for gas chromatographlc (GC) analysis; HEX was qualitatively deter-
mined to be one of the pyrolysls products formed.
Under contract with NIOSH, Boyd et al. (1981) and Dillon (1980) of the
Southern Research Institute developed and validated sampling and analytical
methods for air samples containing HEX. Methods were reliable below the
8-hour time-weighted-average (TWA) Threshold Limit Value (TLV) of 0.1
mg/m3 recommended by the American Conference of Governmental Industrial
Hyg1en1sts (ACGIH).
1810A 3-6 01/06/84
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The current NIOSH method, P 8. CAM 308 (NIOSH, 1979) utilizes adsorption
on Porapak® T (80/100 mesh), desorptlon with hexane (100% for 30 ng of HEX
on 50-100 mg adsorbent), and then analysis by GC-63N1 electron capture
detection. The solid sorbent was cleaned by soxhlet extraction with 4:1
(v/v) acetone/methanol (4 hours), and hexane (4 hours), and was allowed to
dry under vacuum at 50-70°C overnight before cooling In a desiccator. The
pyrex sampling tubes (7 cm long, 6 mm o.d., 4 mm 1.d.) contained a front 75
mg layer of sorbent and a 25 mg backup section. Each section was held 1n
place with two sllylated glass wool plugs.. A 5 mm long airspace was neces-
sary between the front and backup sections. A battery operated sampling
pump drawing air at 0.05 and 2.0 d/mlnute was utilized for personal
sampling of workers. The lowest analytically quantifiable level was 25 ng
of HEX/sorbent sample, assuming 1 ml of hexane-desorblng solvent and a
1 hour desorptlon time by ultrason1cat1on. The upper limit of the method
was 2500 ng/sorbent sample. The method was validated for air HEX concentra-
tions between 13 and 865 yg/m3 at 25-28°C at a relative humidity of >90%.
3.3.1.2. ANALYSIS — Gas chromatography 1s the preferred method for
analyzing HEX 1n air using either flame 1on1zat1on collection or electron
capture detection (e.g., Chopra et al., 1978; Neumelster and Kurlmo, 1978;
WhHmore et al., 1977; NIOSH, 1979). Gas chromatography/mass spectroscopy
(GC/MS) 1s necessary for confirmation (Elchler, 1978).
Several sorbent materials were evaluated for collection of HEX vapor:
Amber 1 He® XAD-2 (20/50 mesh), Porapak® R (50/80 mesh), Amber sorb®
XE-340 (20/50 mesh), Chromasorb® 104 (60/80 mesh), Tenax-GC® (35/60
mesh), Porapak® T (80/100 mesh) and Porapak® T (50/80 mesh). According
to the NIOSH criterion for acceptable methods, a sorbent material must have
a demonstrated sorptlon capacity for the analyte that 1s adequate for
sampling a reasonable volume of workplace air at an established rate.
1810A 3-7 01/19/84
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Table 3-3 enumerates additional factors related to the Porapak® T
collection system.
Gas chromatography with electron capture detection (ECO) was determined
to be the most sensitive analytical technique. For HEX the chromatographlc
response was stated to be a linear and reproducible function of HEX concen-
tration 1n the range of -5-142 ng/ml (25-710 pg Injected) with a correla-
tion coefficient of 0.9993 for peak height measurement. The optimized
operating conditions for this method are shown 1n Table 3-4.
Validation tests were conducted according to NIOSH guidelines. The
accuracy and precision of the overall sampling and analytical procedure for
HEX were evaluated In the concentration range of -13-865 pg/m3. The
lowest analytically quantifiable level (LAQL) of HEX was determined to be
25 ng/sorbent tube. This level represents the smallest amount of HEX that
can be determined with a recovery of >80% and a relative standard deviation
(RSO) of <1054. The desorptlon efficiency of 100% was determined by averag-
ing the levels ranging from near the LAQL of 25 ng to 1000 times the LAQL.
3.3.2. Water. Since HEX 1s sensitive to light in both organic and aque-
ous solutions, the water samples, extracts and standard HEX solutions must
be protected from light. The rate of degradation 1s dependent upon the
Intensity and wavelength with the half-life of HEX being ~7 days when the
solution was exposed to ordinary laboratory lighting conditions (Benolt and
Williams, 1981). Storing the HEX-conta1n1ng solutions 1n amber or red (low
actinic) colored glassware 1s recommended for adequate protection (Benolt
and Williams, 1981).
The XAD-2 resin extraction has been used to concentrate HEX from large
volumes of water. Solvent extraction of water has also proved successful.
1810A 3-8 01/19/84
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TABLE 3-3
Characteristics of The
Porapak T CoTlectlon System3
Characteristic HEX Type/Value
Sorbent material Porapak Tb
(80/100 mesh)
Breakthrough t1mec >8 hour (0.2 l/m1nute)
Breakthrough volume0 >100 ft,
Tube capacity0 >100 g
Average desorptlon 0.94 (27.4 ng)
efficiency of Indicated
quantity of analyte
Sorbent tube 75 mg sorblng layer,
configuration11 25 mg backup layer
Extraction solvent Hexane
aAdapted from Boyd et al., 1978
bTh1s material required cleaning by Soxhlet extraction.
cFor these tests the temperature of the generator effluent was maintained
at 25-28°C and the relative humidity at >90%. The concentration of the
analyte 1n the generator effluent was 1 mg/m3 of HEX.
dThe sorbent tubes were Pyrex (7 cm long by 6 mm o.d. and 4 mm 1.d.).
S1lan1zed glass wool plugs separated the sections.
1810A 3-9 01/04/84
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TABLE 3-4
Optimized GC Analytical Procedure for HEXatb
Characteristic
HEX Type/Value
Detector
Column
Electron capture
354 OV-1 on Gas-Chrom Q
(100/120 mesh) 1n glass
(4 mm 1.d. by 2 m)
OPERATING CONDITIONS
Carrier gas
(20 ma/minute)
Temperatures
Injection port
Column
Detector
Detector parameters
Solvent for compound0
5% CH4, 95% Ar
150°C
135°C
250°C
Detector purge, 5% CH4 with
95% Ar (80 ml/minute)
Hexane
aAdapted from Boyd et al., 1981
bA Hewlett-Packard 5750A gas chromatograph was used.
clhe Injection volume was 5 »j«. of sample and 1 v«, of solvent flush.
1810A
3-10
01/04/84
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The detection limit used for the organic solvent extraction technique was 50
ng/fc vs. 0.5 ng/8, for the XAD-2 method. Using the solvent extraction
method under subdued laboratory lighting conditions, the efficiency of
recovery for an artificially loaded water sample was In the range of
79-8854. The authors concluded that the XAD-2 resin could not be used to
accurately sample HEX 1n water but could be used to screen samples qualita-
tively because of the low detection limit (BenoH and Williams, 1981).
3.3.3. Soil.
3.3.3.1. SAMPLING — In the method described by DeLeon et al.
(1980a), samples were taken from vertical borings 30 feet deep using the
split-spoon method. The samples were then placed 1n jars and sealed with
Teflon®-!1ned screw caps. During shipment, the samples were maintained at
6-10°C. Upon their arrival at the analysis site, they were maintained at
-20°C until required for analysis.
3.3.3.2. ANAYLSIS — DeLeon et al. (1980a) have developed a method
for determining volatile and semlvolatlle organochlorlne compounds 1n soil
and chemical waste disposal site samples. This procedure Involves hexane
extraction followed by analysis of the extract by temperature-programmed gas
chromatography on high-resolution glass capillary columns using electron
capture detection; GC/MS 1s used for confirmation of the presence of the
chlorocarbons. The method has a lower detection limit of 10 yg/g.
Spiked samples of soil were used to test the recovery and reprodudbll-
1ty of the procedure. When a soil sample was spiked with a 10 vg/g con-
centration of HEX, the recovery was 59.8% (S.D. 6.1); at 100 vg/g, 95.9%
(S.D. 15.9); at 300 yg/g, 90.2% (S.D. 4.1). However, as the authors
state, some modifications may be necessary for analysis of the more volatile
one to four carbon chlorinated compounds, since some compounds may be lost
1810A 3-11 01/04/84
-------
1n the concentration step before gas chromatographlc analysis. Of the 11
compounds tested 1n three different concentration levels by the authors, the
100 yg/g HEX sample had the highest standard deviation of all compounds.
Over 100 chemical waste disposal site and soil samples have been evaluated
by this method. In this study, HEX was not detected 1n three typical
samples each taken from a different location within and around a chemical
waste disposal site (DeLeon et al., 1980a).
3.4. BIOLOGICAL MEDIA
3.4.1. Sampling. A method to determine levels of HEX 1n blood and urine
has been described by DeLeon et al. (1980b). This method Involves Isolation
of the compound from the blood or urine sample by liquid-liquid extraction,
GC analysis with electron capture detection and confirmation by GC/MS. Mean
recoveries of 28.8 and 54.5% were reported for blood samples containing 50
and 500 ng/mfc, respectively; for urine, mean recoveries of 35.0 and 51.8%
were reported for samples containing 10 and 200 ng/mt, respectively. The
best recoveries were obtained 1n the study through the use of a toluene-
acetonltrlle extraction combination for blood assays, and petroleum ether
extraction for urine assays. The authors concluded that this method 1s
useful for the detection and Identification of nanogram quantities of HEX,
with low detection limits of 50 ng/mft, for blood and 10 ng/mft, for urine.
Studies by Velslcol Chemical Corporation have shown that up to 30% of the
HEX can be lost If the extracts are concentrated to 0.1 ml. Quantitative
recovery was possible only for volumes of concentrate >0.5 mfc. This
limits the sensitivity of the method. As such, this method may offer a
sensitive means of monitoring occupational exposure.
1810A 3-12 01/04/84
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3.4.2. Analysis. Velslcol Chemical Corporation (1979) has developed
three analytical methods for urine, fish fillet, beef liver, beef skeletal
muscle, beef adipose tissue, beef kidney, chicken liver, chicken skeletal
muscle and chicken adipose tissue. The respective recoveries were: 80+flO
(1-50 ppb), 8U1, 69+4, 884-2, 86+5, 7H3, 55+9, 76+4 and 85+2% The level
of fortification for the tissue samples was 10 ppb. For urine, up to 3154
HEX could be degraded when the fortified urine sample was stored overnight
1n a cooler.
Urine was extracted with hexane, the hexane passed through anhydrous
sodium sulfate, and evaoporated to 1 ma. The limit of detection for HEX
without concentrating the extract was 0.5 ppb. For cattle, poultry and fish
tissues, the tissues were extracted with 2:1 pentane/acetone, the homogenate
diluted with 10% sodium chloride solution, centMfuged, and the pentane
layer transferred Into a separatory funnel. The residues were then parti-
tioned Into acetonltrlle, water diluent added to the acetonltrlle, and then
extraced with pentane. The pentane extract was then treated with concen-
trated sulfurlc add then water, and concentrated to ~3 ma. Upon dilution
to 10 ma with hexane, the solution was treated with a 1:1 concentrated
sulfurlc add/fuming sulfurlc add solution, water, and a 9:1 mixture
(solid) of sodium sulfate/sodlum carbonate. Packed columns (3% OV-1 on Gas
Chrom Q-100/120 mesh-1n 2 m x 2 mm 1.d. glass column) or capillary columns
(30 m x 0.25 mm SE-30 WCOT) can be used for GC using a 63N1-electron
capture detector.
1810A 3-13 01/06/84
-------
4. PRODUCTION, USE, SOURCES AND AMBIENT LEVELS
4.1. PRODUCTION
Because there 1s only one producer of HEX, production statistics are
considered confidential business Information (CBI) and are not available to
the general public. Production estimates for HEX, based on the manufacture
of chlorinated cyclodlene pesticides 1n the early 1970's, were -50 million
pounds per year (Lu et al., 1975). Following restrictions 1n the use of
pesticides produced from HEX, production estimates were lowered to a range
of 8-15 million pounds per year (U.S. EPA, 1977). Technical grade HEX
usually contains other chemicals as contaminants of manufacture (e.g., hexa-
chlorobenzene, octachloropentene or polychlorlnated blphenyls).
4.2. USE
HEX 1s the key Intermediate 1n the manufacture of some chlorinated
cyclodlene pesticides (see Figure 3-1). These include heptachlor, chlor-
dane, aldrin, dleldrin, endrin, mlrex, PENTAC and endosulfan. Another major
use of HEX 1s in the manufacture of flame retardants such as chlorendic
anhydride and dodecachlorotetracyclopentalene. HEX is also used to a lesser
extent in the manufacture of resins and dyes (U.S. EPA, 1980c), and has been
used previously as a general biocide (Cole, 1954). Currently, HEX is pro-
duced at two locations: Memphis, TN and Marshall, IL. All of the HEX pro-
duced at the Illinois plant goes Into the production of chlordane, hepta-
chlor and endrin, while that produced at the Memphis plant is used to pro-
duce heptachlor and endrin as well as the fire-retardant chlorendic anhy-
dride (Levin, 1982a,b).
4.3. SOURCES
HEX is released into the environment during its manufacture and during
the manufacture of products requiring HEX (U.S. EPA, 1980c). It is also
found as an impurity and a degradation product 1n compounds manufactured
1811A 4-1 12/27/83
-------
from HEX (Spehar et al., 1977; Chopra et al., 1978). Limited monitoring
data from production sites Indicated that HEX was present at 18 mg/8. (on
February 2, 1977) 1n the aqueous discharge from the Memphis pesticide plant
(U.S. EPA, 1980c). In the summer of 1977, shortly after these readings, a
new wastewater treatment plant began operation. Prior to construction of
the plant, wastewater flowed directly to the Mississippi River or through
one of Its tributaries (Ella, 1983). Voluntary Improvements In controlling
the discharge from the Memphis plant resulted In reported levels of 0.07 ppb
HEX 1n the Mississippi River, near the mouth of Wolf Creek (Velslcol Chemi-
cal Corp., 1978a). HEX measurements were taken from the effluent stream of
the Memphis North Sewage Treatment Plant from February to July 1982. Month-
ly averages ranging from 0.15-0.61 ppb were reported. Table 4-1 summarizes
these data (Levin, 1982b). In May 1977, HEX was also detected at 0.17
mg/a, 1n the aqueous discharge and at 56 ppb In air samples collected from
a waste site 1n Montague, MI (U.S. EPA, 1980c). At a waste site 1n Hardeman
County, Tennessee, HEX has been shown to be emitted Into the air, ground-
water, wastewater and drinking water (Clark, 1982). Indoor air concentra-
tions of HEX 1n houses with contaminated groundwater supplies ranged from
0.06 to 0.10 pg/m3. HEX has also been Identified 1n the soil and river
sediments downstream from a Virginia manufacturing plant, even after pesti-
cide production was discontinued (U.S. EPA, 1980c).
4.4. AMBIENT LEVELS
Published reports, environmental releases and physlcochemlcal properties
of HEX Imply that 1t will be present mainly 1n the aquatic compartment and
associated with bottom sediments and organic matter. Relatively much lower
concentrations will be found 1n the soil and air compartments.
1811A 4-2 01/19/84
-------
TABLE 4-1
HEX Content 1n the Effluent Stream
of the Memphis North Sewage Treatment Plant, 1982a
Month
February
March
April
May
June
July
Number of
Samples Analyzed
19
15
30
31
29
30
High
0.80
0.60
3.04
0.54
0.57
1.80
HEX Level (ppb)
Low
NDC
NDC
NDC
NDC
NDC
NDC
Average*3
0.32
0.34
0.61
0.24
0.18
0.15
aSource: Levin, 1982b
''Average of all samples taking all ND (not detected) values as zero.
C0etect1on limit 1s <0.01 ppb
1811A
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12/27/83
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4.4.1. A1r. Data sent to EPA regarding emission levels from Velslcol
plants Indicate that small quantities of HEX are emitted Into the air; how-
ever, these data are not considered public Information. Therefore, current
estimates of emissions are not available. No data were found that reported
ambient atmospheric levels of HEX; however, the half-life of HEX 1n air 1s
<5 hours (CupHt, 1980), which greatly reduces the potential for measure-
ment. The highest concentration of HEX measured 1n Hardeman County homes was
0.10 yg/m3, while air levels at the Memphis North Treatment plant ranged
as high as 39 yg/m3 (Clark, 1982; Ella, 1983). A 11st of values 1s
given 1n Table 4-2 for these air samples. This plant handles the wastewater
from a pesticide manufacturer five miles away. The only other air monitor-
Ing was done on an abandoned waste site 1n Michigan where the average HEX
emission rate was 0.26 g/hr ^O.OS).
4.4.2. Water. Environmental monitoring data for HEX are available from a
number of sources. The bulk of the reported levels are contained within the
STORE! data base (U.S. EPA, 1980b). The available monitoring data (STORET)
do not provide specific Information about the sampling site and analytical
methodology. Additionally, the STORET data has not been verified and 1t 1s
not possible, therefore, to critically analyze the reported data.
As previously mentioned, water samples were taken of the Influent waste-
water at the Memphis North Treatment plant (Table 4-3). However, 1n the
Clark (1982) study, HEX was not detected 1n the private wells of Hardeman
County.
Benolt and Williams (1981) sampled both raw and drinking waters from an
Ottawa water treatment plant. No HEX was detected (using solvent extraction
analysis with a detection sensitivity of 50 ng/fc or using the XAD-2 resin
extraction method with a detection sensitivity of -0.5 ng/a.) 1n the raw
1811A 4-4 12/27/83
-------
TABLE 4-2
Area A1r Samples Collected at the
Memphis North Treatment Plan, 1978a
Concentration'', pg/m3
Date
A. WET WELL
May
June
September
October
November
B. GRIT CHAMBER
May
June
July
September
October
November
NC
3
2
2
1
1
3
7
2
4
1
1
HEX
0.03
18
8
15
39
0.03
1.9
0.03
0.03
0.04
12
HEX-BCH
219
278
25
2
7
4.1
6.5
0.5
0.5
1.2
2.6
HCBCHd
87
15
200
1
85
1.9
1.7
0.7
1.1
1.0
4.3
Chlordene
45
16
44
0.1
7.8
0.9
7.5
2.3
2.7
0.8
1.0
aSource: Ella, 1983
bMean values of the number of samples, N, Indicated
CN designates the number of samples collected
dHeptachlorob1cycloheptene
1811A
4-5
12/27/83
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TABLE 4-3
Concentrations of Selected Organic Compounds
1n Influent Wastewater at Memphis North Treatment Plant, 1978a
Concentration'3, yg/L
Date
June
August6
September
October-November
Nc
1
5
2
2
HEX
3
0.8
4
0.8
HEX-BCH
334
329
292
11
HCBCHd
57
115
668
17
Chlordene
87
216
58
32
aSource: Ella, 1983
^Mean values for the number of samples Indicated
cNumber of samples
^Heptachloroblcycloheptene
eThese values are furnished by the chemist at the North plant (Lurker, et
al., 1981).
1811A 4-6 12/27/83
-------
water, but levels ranging from 57-110 ng/i were reported 1n the finished
drinking water, suggesting that HEX was Introduced Into the drinking water
during the treatment process. The authors did not find the source of the
HEX, and are Investigating their findings further (Benolt, 1983).
4.4.3. Food. HEX was qualitatively detected 1n fish samples taken from
water near the Hooker plant 1n Michigan (Spehar et al., 1977); however, none
has been detected 1n fish samples taken from the waters near the Velslcol
plant 1n Memphis (Velslcol Chemical Corp., 1978; Bennett, 1982). No Infor-
mation was available regarding HEX contamination of other foods.
4.4.4. Soil. Ambient monitoring data for the terrestrial environment are
not available. However, 1t appears that these concentrations should be much
lower than concentrations present 1n the aquatic environment. Depositing of
HEX from the atmospheric (and aquatic) compartment Into the terrestrial
environment 1s expected to be minimal. Similarly, direct release of HEX
Into the terrestrial environment (I.e., as an Impurity 1n chlorinated pesti-
cides) should be decreasing with the possible exceptions of disposal at
waste sites (e.g., Michigan and Tennessee) and of other Improper disposal
methods.
4.5. RELATIVE SOURCE CONTRIBUTIONS
Available data are Insufficient to derive relative source contributions.
After considering the available Information, the U.S. EPA has reported that
human exposure through the environment via air or water would be extremely
low except for workers and residents near manufacturing, shipping and waste
sites, and concluded that exposure was not considered significant or sub-
stantial (U.S. EPA, 1982).
4.6. SUMMARY AND CONCLUSIONS
Measured ambient concentrations of HEX are available for aquatic com-
partments (U.S. EPA, 1980b). These Include freshwater and sediments of
1811A 4-7 12/27/83
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streams, lakes and wells. Limited data are also available for estuaries and
oceans. Additional saltwater, as well as atmospheric and terrestrial moni-
toring data, are needed to determine the ambient concentrations 1n these
compartments.
Freshwater levels of HEX are estimated to range from 0-800 pg/l,
based on non-verified STORE! data. Estimates for atmospheric concentrations
are not available In the literature. Estimates for HEX concentrations 1n
soils are limited. To properly conclude the levels of HEX 1n the environ-
ment, careful monitoring must be conducted. To date, this Information 1s
very limited.
A1r levels In areas near previous dump sites have been shown to be
high. Some contamination of drinking (well) water exists near these sites.
High concentrations of HEX have been recorded 1n wastewater and In two Inci-
dences have Increased the ambient HEX levels Inside treatment facilities
above the ACGIH time-weighted average.
1811A 4-8 12/27/83
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5. ENVIRONHENTAL FATE AND TRANSPORT
5.1. FATE
The evidence presented 1n this section Indicates that HEX 1s not persis-
tent 1n the air, water or soil. Photolysis, hydrolysis and blodegradatlon
have been shown to be the key processes Influencing the environmental fate
of HEX.
5.1.1. A1r. Little relevant Information 1s available to predict the fate
of HEX 1n air. Its tropospherlc residence time was estimated by CupHt
(1980) to be ~5 hours based on estimated rates of reaction with hydroxyl
radicals and ozone. The respective reaction rates were theoretically esti-
mated to be 59xlO~12 and 8xlO~18 cm3 molecule"1 sec"1. In estima-
ting the tropospherlc residence time, or time for a quantity of HEX to be
reduced to 1/e (or -37%) of Us original value, 1t was assumed that the rate
constants calculated at room temperature for both reactions are valid 1n the
ambient atmosphere and that the background concentrations of hydroxyl radi-
cal and ozone are 106 and 1012 molecules cm"3, respectively. Atmos-
pheric photolysis of HEX was also rated as "probable", since HEX has a
chromophore that absorbs light 1n the solar spectral region, and 1s known to
photolyze 1n aqueous media (see Section 5.1.2.1.). No attempt was made to
estimate a rate for atmospheric photolysis. CupHt (1980) listed the theo-
& *
retlcal degradation products as Cl CO, dlacylchlorldes, ketones and free
Cl radical, all of which would be likely to react with other elements and
compounds. ,,^_ , ;, ...!/,. , - M, . . .. , c ,. ,Lt ,„ , ,,,,,|ivl „,
Korte (1978) demonstrated the photom1nera!1zat1on of HEX (1.9 g) applied
to silica gel (400 g) after 4 days 1rrad1aton (\ > 290) 1n an atmosphere
of pure oxygen. The mineralization products were chloride (C1-, 44.9%),
carbon dioxide (CO , 48.3%), chlorine gas (Cl , 5.4%) and carbon monox-
ide (CO, 1.2%).
A ^ , ,.,-.,-> • .'.-<""• ' • °(- -'- - "•
1812A 5-1 ]i,,y< <•;• - '-'' 12/27/83 -•"•••
; ,' -"^" • * l " . <•;
-------
5.1.2. Water. In the event of release Into shallow or flowing bodies of
water, degradatlve processes such as photolysis, hydrolysis and blodegrada-
tlon, as well as transport processes Involving volatilization and other
physical loss mechanisms, are expected to be prominent 1n HEX dissipation.
In deeper, nonflowlng bodies of water, hydrolysis and blodegradatlon may
become the predominant fate processes.
5.1.2.1. PHOTOTRANSFORMATION — Zepp et al. (1979) and Wolfe et al.
(1982) reported the results of U.S. EPA studies on the rate of HEX photo-
transformation 1n water. Under a variety of sunlight conditions, 1n both
distilled and natural waters of 1-4 cm depth, phototransformation half-life
was <10 minutes. Addition of natural sediments to distilled water contain-
ing HEX had little effect on phototransformation rate. These findings Indi-
cated that the dominant mechanism of HEX phototransformation was direct
absorption of light by the chemical, rather than photosens1t1zat1on reac-
tions Involving other dissolved or suspended materials.
The direct photoreactlon of HEX 1n water was also studied under control-
led conditions 1n the laboratory using a monochromatic light (313 nm) Isola-
ted by filters from a mercury lamp. Phototransformation rate constants,
computed for the study location (Athens, GA, 34°N latitude), agreed with
those observed In the sunlight experiments described above. Rate constants
were also computed for various times of day at 40°N latitude. The near-
surface phototransformation rate constant of HEX at this latitude on cloud-
less days (averaged over both light and dark periods for a year) was
3.9 hr"1, which corresponds to a half-life of 10.7 minutes (Zepp et al.,
1979; Wolfe et al., 1982).
These researchers suggested that the primary phototransformation product
was the hydrated form of tetrachlorocyclopentadlenone (C Cl 0, TCPD),
1812A 5-2 12/27/83
-------
although 1t was not Isolated. Several chlorinated photoproducts with higher
molecular weights than HEX were detected by GC/MS analysis of the reaction
mixture. Photolysis of HEX 1n methanol gave a product Identified as the
dimethyl ketal of TCPO (Wolfe et al., 1982). According to Zepp et al.
(1979), H 1s likely that TCPO exists predominantly 1n Us hydrated form 1n
the aquatic environment. The compound was not Isolated, supposedly because
1t rapidly dlmerlzes or reacts to form higher molecular weight products.
To the contrary, other research Indicates that formation of higher
molecular weight products 1s a relatively minor pathway of phototransforma-
tlon. Yu and Atallah (1977b) found that at a concentration of 2.2 mg/8. 1n
water, uniformly labeled 14C-HEX was rapidly converted to water-soluble
products upon Irradiation with light from a mercury-vapor lamp (light energy
40-48% ultraviolet, 40-43% visible, remainder Infrared). In exposures of
0.5-5.0 hours, 46-53% of the radlolabel was recovered as water-soluble prod-
ucts (compared to 7% at Initiation), whereas the amount recovered by organic
(petroleum ether) extraction decreased with Increasing exposure duration
from 25 to 6% (compared to 66% at Initiation). No HEX was detected among
the photoproducts 1n the organic extraction.
Butz et al. (1982) also found that 14C-HEX, when dissolved and Irradi-
ated as above, was rapidly photodegraded. Failure to detect HEX after 10
minutes, with a detection limit of 0.13% of the starting amount, suggested a
photolytlc half-life under these conditions of <1.03 minutes, assuming
first-order kinetics. Reaction products were extracted and radloassayed.
After both 5- and I0-m1nute exposures, 44% of the recovered radioactivity
was 1n the water-soluble fraction (total percent recovery was not speci-
fied). Photoproducts were purified by thin-layer chromatography (TIC) and
Identified by GC/MS. The authors concluded that pentachlorocyclopentenone
1812A 5-3 12/27/83
-------
O) was the major degradation Intermediate, which subsequently
A
degraded to water-soluble products. Dlmerlzatlon. of pentachlorocyclopente-
none to hexachlorolndenone (CqCl,0) was thought to occur by hydrolysis,
rather than phototransformatlon, and to represent a minor pathway {Figure
5-1). Other high molecular weight compounds Identified were believed to be
artifacts of the GC/MS analysis of pentachlorocyclopentenone. M1rex and
kepone were analyzed for but not detected after 5 hours Irradiation (Butz et
al., 1982).
The environmental fate and transport of HEX was modeled 1n four simula-
ted aquatic ecosystems using the Exposure Analysis Modeling System for Toxic
Organic Pollutants 1n Aquatic Ecosystems (EXAMS) with experimentally derived
constants (Table 5-1) (Zepp et al., 1979; Wolfe et al., 1982). The four
ecosystems considered In the model Included a 35 km x 100 m river segment; a
small eutrophlc pond with a 31-day retention time 1n the water column; and
two lakes (35 ha), one eutrophlc and the other a stratified ollgotrophic
lake. Results Indicate that 1n the river, export from the system and photo-
lysis were the dominant processes (Table 5-2). In the simulated pond and
both lake environments, photolysis was predicted to be the dominant process,
accounting for more than 80% of the HEX transformation occurring at each of
these sites. Although HEX 1s quite reactive, the recovery times (I.e., the
times needed to reduce steady-state concentration by five halfUves) 1n the
pond and lakes were predicted to be on the order of 2-3 months. This was
attributed to slow release of HEX from the bottom sediments where the photo-
lytlc rate 1s retarded (Wolfe et al., 1982).
5.1.2.2. HYDROLYSIS — Studies of the hydrolysis of HEX Indicate that
at 25-30°C and 1n the environmental pH range of 5-9, a hydrolytlc half-life
of -3-11 days 1s observed (Wolfe et al., 1982; Yu and Atallah, 1977a).
Zi
1812A 5-4 12/27/83
-------
Cl
Cl
Ar.
Cl^x^CI
Cl Cl
-Cl
»OH
HydfOlytl*
-2MCI
-COCI,
Ma, or
Minor
Cl
f
Cl Cl
Wii«r-*olubl*
Photoproducl*
c. c.^V^V^c.
Cl 0
XI
FIGURE 5-1
Proposed Pathway of Aqueous HEX Phototransformatlon
Source: Butz et al., 1982
1812A
5-5
12/23/83
-------
TABLE 5-1
Summary of Constants Used 1n the Exposure
Analysis Modeling System (EXAMS) at 25°C In Water*
Constants
Water solubility
Henry's law constant
Octanol/water partition
coefficient
Photolysis
Hydrolysis
Oxidation
B1odegradat1on
Symbols, Units
Ks, mg/8.
KH» atm mVmole
Kow
Kp, hr
K^pQ, hr
Kox, M"1 sec"1
Kg, ma org"1 hr""1
Values Used
1.8
2.7xlO~2
l.lxlO5
3.9
4.0xlO~3b
lxlO~loC
lxlO'sd
aAdapted from Wolfe et al., 1982
bExtrapolated to 25°C
cEst1mated value (see Wolfe et al., 1982)
dTh1s Is a maximum value based on the observation that there was no
de tectable difference 1n the hydrolysis rate 1n either sterile or
nonsterlle studies and measured organism numbers (plate counts).
1812A
5-6
12/27/83
-------
TABLE 5-2
Summary of Results of Computer Simulation of the Fate and Transport
of Hexachlorocyclopentadlene 1n Four Typical Aquatic Environments3
River
Pond
Eutrophlc Ollgotrophlc
Lake Lake
Accumulation factor
Distribution (percent)
Water column
Sediment
5.4xl04
1.22
98.78
2.4
14
86
17
12.97
87.03
54
2.91b
97.09
Recovery t1mec (days)
Load reduction (percent)
by processes:
52
81
58
87
Hydrolysis
Oxidation
Photolysis
B1odegradat1on
(biolysis)
Volatilization
Export0"
8.04
0.00
18.68
0.57
0.69
72.02
17.85
0.00
80.39
0.23
1.33
0.20
8.29
0.00
89.18
0.30
1.56
0.01
16.50
0.00
82.41
0.01
1.08
0.00
aAdapted from Wolfe et al., 1982, with correction applied.
bValue was Incorrectly reported as 32.91 1n original paper.
clhe time needed to reduce steady-state concentration by five half-lives.
dPhys1cal loss from the system by any pathway other than volatilization.
1812A
5-7
12/27/83
-------
Hydrolysis Is much slower than photolysis (see Table 5-1), but may be a sig-
nificant load-reducing process 1n waters where photolysis and physical
transport processes are not Important (I.e., 1n deep, non-flowing waters).
Wolfe et al. (1982) found hydrolysis of HEX to be Independent of pH over
a range of 3-10. The rate was adequately described by a neutral hydrolysis
rate constant (KH2o ± standard deviation) of (1.5+0.6) x 10"6 sec"1 at 30°C,
which corresponds to a half-life of 5.35 days. The rate constant was depen-
dent on temperature at pH 7.0 with the half-life estimated to be 3.31, 1.71
and 0.64 days at 30, 40 and 50°C, respectively. The addition of various
buffers or 0.5 M NaCl did not affect the hydrolysis rate constant, suggest-
ing that the rate constant obtained would be applicable to marine environ-
ments as well. The addition of natural sediments sufficient to adsorb up to
92% of the compound caused the rate constant to vary by less than a factor
of 2. It was therefore concluded that sorptlon to sediments would not
significantly affect the rate of hydrolysis (Wolfe et al., 1982).
Some variability of hydrolysis rate with changes 1n pH was demonstrated
by Yu and Atallah (1977a). They studied the stability of ^C-HEX In water
at pH 3, 6, 9 and 12 at 25°C and 45°C, under dark conditions. HEX was rela-
tively unstable at alkaline pH. At 25°C, the half-lives were 11.4, 11.4 and
6.0 days at pH 3, 6 and 9, respectively, and <2 hours (0.1 day) at pH 12.
At 450C the half-lives at pH 3, 6 and 9 were 9.2, 10.6 and 4.4 days, res-
pectively. Degradation of HEX resulted 1n water-soluble products, and based
upon their chromatographlc behavior, the hydrolysis products appear to be
polyhydroxy compounds, with CO as a minor hydrolysis product.
In the Wolfe et al. study (1982), a preliminary Investigation was con-
ducted to determine the products from hydrolysis. The hydrolysis reaction
was conducted at 60-70°C In 40% acetonltrlle-water at 10"* M HEX and
1812A 5-8 01/19/84
-------
proceeded through approximately two half-lives. After extraction and con-
centration of the Upophlllc reaction products, analysis by GC/MS showed
nine major peaks 1n the chromatogram. Several of these were high molecular
weight compounds, but, as with the Yu and Atallah study (1977a), Identifica-
tion was not positive.
The degradation of HEX by hydrolysis In the EXAMS model environments,
consisting of a simulated river, pond, eutrophlc lake and ollgotrophic lake
were estimated to be 8.0, 17.9, 8.3 and 16.5%, respectively, of the total
Initially present (see Table 5-2). Hydrolysis 1n these aquatic environments
was considered to be minor relative to photolysis In the overall degradation
of HEX (Wolfe et al., 1982). The above data Indicate that at neutral pH the
hydrolysis half-life 1s from 3-11 days, compared to a much more rapid photo-
lytlc half-life of <10 minutes.
5.1.2.3. OXIDATION -- HEX 1s not expected to be oxidized under ordi-
nary environmental conditions. In the laboratory, HEX has been reported to
react with molecular oxygen at 95-105°C to form a mixture of hexachlorocy-
clopentenones (Molotsky and Ballweber, 1957). However, based on an estima-
ted first order oxidation rate constant of lxlO~10 M"1 sec"1 at 25°C
1n water (see Table 5-1), the EXAMS computer simulation of Wolfe et al.
(1982) predicted that HEX would not be oxidized 1n the simulated river,
pond, eutrophlc lake or ollgotrophic lake (see Table 5-2).
5.1.2.4. BIODEGRADATION — Tabak et al. (1981) stated that HEX 1s
blodegraded fairly rapidly 1n a static laboratory culture. Bottles contain-
ing HEX added to 5 mg yeast extract/8, as the synthetic medium were Inocu-
lated with an unspecified domestic wastewater and kept 1n the dark at 25°C.
1812A 5-9 12/27/83
-------
Extractions for gas chromatography were done with 20 ml portions of
methylene chloride (neutral pH) at an efficiency of >75%. HEX at 5 and 10
mg/J. (concentrations exceeding the compound's aqueous solubility limits)
was degraded below the GC method minimum sensitivity limits (0.1 mg/8.) 1n
7 days. Volatilization was stated not to occur during a 10-day period 1n
which control bottles having no Inoculum were studied. The Importance of
chemical hydrolysis was not discussed by the authors. According to studies
presented 1n Section 5.1.2.2., 7 days could represent as much as 1-2 hydro-
lytlc half-lives, accounting for loss by as much as a factor of 4. Based on
nominal concentrations, loss of HEX 1n these tests exceeded a factor of
50-100; therefore, hydrolysis cannot fully account for Us disappearance.
Atallah et al. (1980) reported on an aqueous aerobic blodegradabilHy
study to determine 1f, and at what rate, HEX can be degraded to CO . The
Inoculum was a mixed acclimated culture containing secondary municipal waste
effluent and several strains of Pseudomonas putlda. HEX, labeled with
i4C, was the sole source of carbon In the study, with the exception of
trace levels of vitamins. Total removal of 14C, primarily as volatile
organlcs, was >80% In the first day 1n both unlnoculated (45 mg/a. HEX) and
Inoculated (4.5 and 45 mg/8. HEX) media, although removal was slightly
higher 1n Inoculated media. 14CO was released from both media, Indica-
ting C0_ was a product from hydrolysis as well as blodegradatlon. The
rate of conversion to C0? was Initially higher 1n the unlnoculated, but
after a week, became higher 1n the Inoculated media (Figure 5-2).
These studies show clearly that HEX can be blodegraded In aquatic media
under laboratory conditions. However, Wolfe et al. (1982) stated that they
failed to detect any difference 1n the HEX degradation rate between hydro-
lysis experiments where sterile and nonsterlle natural sediments were added
1812A 5-10 12/27/83
-------
LL-S
VZL8L
X CONVERSION TO
c/o o
o -n
c
-> o
O at
i-f i-r -n
ft) -» I—I
—•00
—i 3 <=
CU TO
J O m
-ft
fD tn
l-f M I
00 O
o
o
o
K
en
3 ** S
* 3 a
M «
5 i
C c
3 £
iniiniiiiiiiiiiiiiii
-------
to water (1.0 g/100 ml). Thus they calculated a relatively low value
(IxlCT5 ms, org"1 hr"1; see Table 5-1) as a maximum blodegradatlon
rate, and consequently blodegradatlon was estimated to be a relatively unim-
portant fate process 1n the EXAMS model (see Table 5-2).
5.1.2.5. ADSORPTION — On the basis of computer simulations, Wolfe et
al. (1982) predicted that HEX would adsorb strongly to sediments found 1n
various aquatic environments (see Table 5-2). The distribution 1n sediments
from a simulated river, pond, eutrophlc lake and ol1gotroph1c lake was esti-
mated to be 98.8, 86.0, 87.0 and 97.T/4, respectively, of total HEX 1n the
system (see Table 5-2). The sorptlve properties of HEX 1n relation to soil
are discussed below.
5.1.3. Soil. Upon release onto soil, HEX Is likely to adsorb strongly to
any organic matter or humus present (Kenaga and Goring, 1980; Weber, 1979).
With time, HEX concentrations should decrease as populations of soil micro-
organisms better adapted to metabolize HEX Increase (R1eck, 1977b,c; Ihuma
et al., 1978). Volatilization (See Section 5.2.3.), photolysis, and various
chemical processes may also dissipate the compound 1n certain soil environ-
ments.
5.1.3.1. ADSORPTION — The soil adsorption properties of compounds
such as HEX can be predicted from their soil organic carbon-water partition
coefficients (K ). Kenaga (1980) examined the adsorption properties of
100 chemicals and concluded that compounds with K values >1000 are
tightly bound to soil components and are Immobile 1n soils. Those possess-
ing values below 100 are adsorbed less strongly and are considered moderate-
ly to highly mobile. Accordingly, the theoretical K value 1s useful as
an Indicator of potential soil Teachability or binding of the chemical.
1812A 5-12 12/27/83
-------
K values also Indicate whether a chemical 1s likely to enter water by
oc
leaching or adsorbed to eroded soil particles. Because K values for HEX
are not available 1n the literature, these values were calculated using the
mathematical equation developed by Kenaga and Goring (1980) and Kenaga
(1980). The equation used was:
log K = 3.64 - 0.55 (log WS) +1.23 OH
oc
where WS 1s water solubility (mg/8.), and the 95% confidence limits are
+1.23 orders of magnitude (OM). The calculated range of K values for
HEX using the reported water solubility values of 2.1 mg/lt (Dal Monte and
Yu, 1977), 1.8 mg/S, (Wolfe et a!., 1982) and 0.805 mg/S. (Lu et al.,
1975) are 2903, 3159 and 4918, respectively. These calculated KQC values
are all >1000 and suggest that HEX Is tightly bound to soil components and
Immobile 1n the soil compartment. Similarly, BMggs (1973) concluded that
compounds with a log octanol/water partition coefficient (log P) >3.78 are
Immobile 1n soil. The measured log P value of HEX 1s 5.04 (Wolfe et al.,
1982), further Indicating that the compound 1s Immobile with respect to
leaching.
The only sorptlon data found 1n the literature were for an experimental-
ly flooded soil. Weber (1979) reported that an average of 68% of applied
HEX was adsorbed to Cape Fear loam soil present 1n aqueous solutions. In
these experiments, aqueous solutions (50 ml) containing 0.0, 0.41 (1.5
viM), 0.82 (3.0 yM) and 1.64 (6.0 pM) mg/kg of 14C-HEX were added to
soil samples (0.50 mg) 1n stoppered bottles, which were shaken at room temp-
erature for 24 hours. Standards, controls and two replications were used 1n
all cases. The difference between the Initial and the 24-hour equilibrium
concentration of radlolabel 1n water was considered to be the amount of HEX
adsorbed to soil. Less than 5% of the radlolabel was lost
1812A 5-13 12/27/83
-------
from the bottles over the 24-hour period. About 62, 66 and 75% of the
applied dose was adsorbed to the soil at 0.41, 0.82 and 1.64 ppm concentra-
tions, respectively. Weber (1979) suggested that the HEX 1s very strongly
adsorbed by organic soil colloids because of Us UpophlUc character.
5.1.3.2. BIODEGRADATION — The metabolism of HEX by soil micro-
organisms apparently 1s an Important process 1n Us environmental degrada-
tion. Soil degradation 1s rapid under nonsterlle aerobic and anaerobic
conditions, with Indirect evidence for microblal Involvement reported by
R1eck (1977b,c). In one of his studies, R1eck (1977b) used several types of
treatments and soil pHs to determine 1f the blodegradatlon of HEX 1n Maury
silt loam soil was either biologically or chemically mediated, or both
(Figure 5-3). Soils were Incubated 1n glass flasks covered with perforated
aluminum foil and kept on a laboratory shelf, presumably exposed to ambient
lighting through the flask walls. When 14C-HEX was applied to nonsterlle
soil at 1 mg/kg, only 6.1% was recovered as nonpolar material (either HEX or
nonpolar degradation products) 7 days after treatment, and -71.7% was polar
and unextractable material. Adjustment of pH to 4 or 8 had little effect on
these results. By comparison, 1n autoclaved soil (the control), 36.1% of
the applied dose was recovered as nonpolar material and only 33.4% recovered
as polar and unextractable material (see Figure 5-3). The degradation of
HEX under anaerobic (flooded) conditions occurred at a slightly faster rate
than under aerobic conditions. However, no sterile, flooded control was
used to determine the effects of hydrolysis, which could have accounted for
the observed difference 1n this treatment. The mean total recovery 1n all
treatments decreased from 67% at 7 days to 55% at 56 days. This decrease
was attributed to volatilization of HEX and/or degradation products.
1812A 5-14 12/27/83
-------
so
40
O
tu
O.
a.
3O
2O
O
• UNALTERED
D pH 4
O pH 8
A AUTOCLAVED
A SODIUM AZIDE
• FLOODED
DAYS AFTER TREATMENT
FIGURE 5-3
Persistence of Nonpolar 14C when 14C-HEX 1s Applied
to Unaltered and Altered Soils
Source: Adapted from R1eck, 1977b
1812 A
5-15
12/23/83
-------
Volatilization from soil was examined 1n another experiment (Rleck,
1977c). In a 14-day study, radiocarbon volatilized from nonsterlle,
14C-HEX-treated soil was trapped and assayed. Over the study duration, a
total of 20.2% of the applied 14C was trapped; 11.2% 1n hexane and 9.0% 1n
ethanolamlne-water. Most of the hexane fraction (9.3% of applied 14C) was
trapped during the first day, probably representing volatilized HEX. How-
ever, the ethanolamlne-water fraction, considered to represent evolved
C0?, was released gradually over the 14-day period. In the soil analysis,
nonpolar (extractable) and polar (extractable and unextractable) material
accounted for 3.4 and 40.0% of the dose, respectively, during the 14 days;
thus, total recovery was only 63.6% Including volatilization. No metabolic
products were Identified 1n either study by Rleck (1977b,c).
In these studies (Rleck, 1977b,c), HEX was degraded to polar material 1n
both sterile and nonsterlle soils, Indicating the occurrence of an abiotic
degradation process such as hydrolysis by soil water and possibly some
photolysis. Since degradation occurred more quickly In nonsterlle soils,
blodegradatlon evidently was also occurring. Volatilization of HEX occurred
mainly during the first day, and apparently represented no more than 11.2%
of the total amount applied (Rleck, 1977c), although the low total recovery
in this experiment decreases the reliability of this figure.
Under contract with the U.S. EPA, Thuma et al. (1978) studied the
feasibility of using selected pure cultures (organisms not Identified) to
biodegrade spills of hazardous chemicals on soils, including HEX. They
tested 23 organisms and found that from 2-76% of the HEX had been removed
from the aqueous culture medium within 14 days. Seven of the 23 organisms
degraded more than 33% of the HEX within 14 days (Table 5-3). Losses of HEX
not due to blodegradatlon were accounted for by the use of controls.
1812A 5-16 12/27/83
-------
TABLE 5-3
M1crob1al Degradation of HEX During
14-day Exposure 1n a Test Medium*
Organism
Code Number
Control 1
Control 2
006
016
020
022
123
369
505
HEX Remaining 1n
Test Medium (ppm)
635
630
410
415
410
150
395
350
265
Percent Degraded
Relative to Control
—
--
35
34
35
76
38
45
58
*Source: Adapted from Thuma et al., 1978
1812A 5-17 12/27/83
-------
These studies Indicate that the persistence of HEX 1n soil Is brief,
with degradation of >90% of applied HEX to nonpolar products within ~7 days.
Factors contributing to this loss Include abiotic and blotlc degradation
processes and volatilization, although the relative Importance of each 1s
difficult to quantify given the limited Information available.
5.2. TRANSPORT
5.2.1. A1r. The vapor pressure, water solubility, vapor density,
adsorption properties, rapid photolysis (Wolfe et al., 1982) and high reac-
tivity (Callahan et al., 1979) of HEX combine to affect Us atmospheric
transport. The atmospheric transport of HEX vapor from a closed Hooker
Chemicals and Plastics Corp. site at Montague, Michigan, was demonstrated by
Peters et al. (1981). HEX was detected 1n air an unspecified distance down-
wind of the site, at concentrations of 0.032-0.053 ppb (0.36-0.59
pg/m3). Based on the concentration ratio of HEX and a tracer gas re-
leased at a known rate, the average HEX emission rate during the measurement
period was calculated to be 0.26 g/hour.
Volatilization of HEX from water may occur following either Industrial
discharge [e.g., a concentration of 18 mg/S. was found 1n the aqueous dis-
charge at a Memphis pesticide plant (U.S. EPA, 1980c)] or accidental spill.
The tendency of HEX to adsorb to organic matter 1n water or soil would limit
the compound's volatility, as would suspended solids 1n surface water.
Transport of HEX vapor will also be limited by the estimated atmospheric
residence time, based on photolysis, hydrolysis and ozone reaction rates, of
~5 hours (Cupitt, 1980). HEX adsorbed onto aquatic or terrestrial particles
may also enter the atmosphere and be transported 1n the air for a time while
being transformed by photolysis or other processes.
1812A 5-18 12/27/83
-------
As part of an experiment with chlordane, Bevenue and Yeo (1969) found
some Interesting vaporization and adsorption properties of HEX, which may
exist 1n an amount as large as 1% 1n commercially available chlordane.
Small quantities of HEX (0.5 mg) 1n open vials were placed 1n closed glass
vessels containing 20 ma of either distilled water or isooctane, so that
only vaporized HEX could contact the solvent. Vessels were stored under
fluorescent lighting. Gas chromatographlc data from the solutions of dis-
tilled water Initially revealed the presence of adsorbed vapor of HEX and
Us degradation products, Indicating transport from air to water. Beyond 3
days exposure, however, the chemical and Us products had completely disap-
peared from the GC chromatogram, Indicating either dissipation or decomposi-
tion of the compound. The data obtained from the Isooctane solutions re-
vealed a different GC pattern. No degradation was observed after 24 hours,
while a multiple-peak chromatogram (Indicating degradation products) was
obtained after the solutions were exposed 7-21 days. This chromatogram
suggests that the compound may be susceptible to atmospheric oxidation
and/or photodecomposHlon (NCI, 1977). The more rapid disappearance of
compound and degradation products 1n water than In the Isooctane solution
may further Indicate the occurrence of hydrolysis.
More Information on the volatility and adsorption of HEX 1s presented 1n
Sections 5.2.2. and 5.2.3., respectively.
5.2.2. Water. HEX Introduced Into water bodies may be transported 1n
either undlssolved, dissolved or adsorbed forms. In Us undlssolved form,
HEX will tend to sink owing to Us high specific gravity and may then become
concentrated 1n deeper waters, where photolysis and volatilization would be
precluded. Some HEX may be dissolved 1n water (up to ~2 mg/l) and then be
dispersed with water flow (I.e., 1n a river). HEX tends to adsorb onto
1812A 5-19 12/27/83
-------
organic matter because of Us UpophlUc nature and may then be transported
with water flow 1n a suspended form. Transport to the air may occur by
volatilization, which was measured In laboratory studies (Kllzer et al.,
1979; Weber, 1979) and predicted using the EXAMS model by Wolfe et al.
(1982). However, suspended solids In surface water may be a major factor 1n
reducing volatilization.
Weber (1979) measured the volatility of 14C-HEX from distilled water
following the Incubation of the glass-stoppered and unstoppered test bottles
shaken at room temperature for 24 hours. Experiments were performed with
standard HEX solutions of 1.5xlO~6M (0.41 mg/9.) 1n distilled water,
with readings taken 24 hours later. From the full glass-stoppered bottles,
only 4-5% of the HEX was lost, while in the half-full stoppered bottles,
15-16% of the chemical was missing. This suggests that head space in the
bottle contributed to the loss of HEX. The volatility of HEX was shown by
the loss of 45-47% from the half-full, unstoppered bottles over the 24-hour
period.
Kllzer et al. (1979) determined the rate of 14C-HEX volatilization
from water as a function of the rate of water evaporation. Bottles contain-
ing aqueous HEX solutions (50 yg/8.) were kept without shaking at 25°C.
The escaping vapor condensed on a "cold finger" and was quantified by liquid
scintillation spectroscopy. Based on recovery of added label, the HEX vola-
tilization rates for the first and second hours of testing were calculated
to be 5.87 and 0.75% / ml HO, respectively. Since the water evaporation
rate was 0.8-1.5 ml/hour, rates for HEX were within the ranges of 4.7-8.8
and 0.6-1.1%/hour, respectively. These results suggest that a fairly rapid
initial volatilization occurred at the water surface, and that by the second
hour, diffusion of HEX to the water surface may have been limiting because
of the static conditions of the test. If the rate observed during the
1812A 5-20 12/27/83
-------
second hour had continued for the remainder of 24 hours, total loss would
have been -18-34%, or somewhat less than that observed 1n the above test
(Weber, 1979) where unstoppered bottles were shaken.
In the aqueous blodegradatlon test of Atallah et al. (1980) described 1n
Section 5.1.2.4., a very high rate of volatilization was determined. Over
80% of the radlolabel added as 14C-HEX had disappeared after the first
day, even from unlnoculated media. Most was found to have volatilized
(total recovery averaged 94%) and was primarily 1n organic form. The physi-
cal conditions of the test, such as covering, shaking or aeration of test
solutions, were unspecified. In addition, disappearance of label at Initia-
tion was >50%. This peculiarity was not explained, but could be due to the
use of HEX concentrations of 4.5 and 45.3 mg/8., which exceed the limit of
aqueous solubility.
Wolfe et al. (1982) also studied the evaporation rate of HEX from water
and experimentally determined the Henry's law constant (H) to be 0.027+0.010
atm mVmole. This value corresponds with 0.0137 and 0.0357 atm mVmole
calculated from the measured vapor pressure (0.08 mmHg at 25°C) (Irish,
1963) and the water solubilities (2.1 and 0.805 mg/8.) (Dal Monte and Yu,
1977; Lu et al., 1975, respectively), according to the following equation:
Vapor pressure (atm)
H =
Water solubility (mole/m3)
The mathematical EXAMS model (see Section 5.1.2.) was used to Indicate the
relative Importance of volatilization and other processes 1n the fate and
transport of HEX (load reduction) of four aquatic systems (see Table 5-2).
The model Indicated that volatilization of HEX from a river, pond, eutrophlc
lake and ollgotrophic lake would account for only 0.69, 1.33, 1.56 and 1.08%
of load reduction, respectively. These values are quite low compared to the
laboratory values described previously. This discrepancy 1s apparently due
1812A 5-21 12/27/83
-------
to the fact that the model estimates that 86-99% of the HEX present in these
systems will be adsorbed to sediment, and thus not subject to volatiliza-
tion. Experiments measuring vaporization of HEX from water-sediment systems
have not been conducted.
Export (I.e., physical loss by methods other than volatilization) was
predicted to be a very important transport mechanism in the simulated river
environment (Wolfe et al., 1982). Using the EXAMS model, export accounted
for load reductions of 72% in the river, as compared to the three nonflowing
environments mentioned previously, where photolysis was the dominant removal
mechanism.
5.2.3. Soil. As indicated previously (Section 5.1.3.1.), HEX in soils is
predicted to be tightly adsorbed to organic matter and relatively resistant
to leaching by soil water. Thus, the primary routes of transport for soil
applied HEX are via movement of particles to which it is adsorbed or via
volatilization. No data are available pertaining to HEX transport on soil
particles; however, a few studies have determined the rate of volatilization
from soils.
Kilzer et al. (1979) determined that 14C-HEX volatilized from moist
soils (sand, loam and humus) at a faster rate in the first hour than in the
second hour of the study. HEX (50 jjg/kg) was placed 1n bottles with each
soil type and shaken vigorously. The bottles were Incubated for 2 hours at
25°C, apparently without shaking. The evaporating HEX condensed on a "cold
finger" and was quantified by liquid scintillation counting. For sand, loam
and humus, the volatilization rate was expressed as the percentages of
applied radioactivity per ma of evaporated water and were for the first
hour 0.83, 0.33 and 0.14%, while for the second hour they were 0.23, 0.11
and 0.05%, respectively. Volatilization was much higher from the sand.
1812A 5-22 12/27/83
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For HEX and nine other tested chemicals, KHzer and coworkers found that the
volatilization rate from distilled water cannot be used to predict the rate
from wetted soils. Among the chemicals tested, there was no correlation
between water solubility or vapor pressure and volatllzatlon from soils.
The volatilization rate for HEX 1n soil was primarily dependent upon soil
organic matter content, mainly because of the highly adsorptlve properties
of HEX.
R1eck (1977c) measured the rate of volatilization of HEX from Maury silt
loam soils (see Section 5.1.3.2.). Following the application of 100 mg of
14C-HEX to soil, the cumulative evaporation of HEX and Us nonpolar meta-
bolites (penta- and tetrachlorocyclopentadlene} on days 1, 2, 3, 5, 7 and 14
were 9.3, 10.2, 10.6, 10.8, 11.0 and 11.2%, respectively. The results Indi-
cate that HEX evaporation to air occurred mainly during the first day fol-
lowing application and was probably associated with the surface soil only.
When compared with data presented 1n the preceding section (5.2.2.),
these studies demonstrate that HEX volatilizes from soils much more slowly
than from sediment-free water. This difference is most likely due to
adsorption of HEX to the soil matrix, and possibly to slow diffusion to the
soil surface.
5.3. BIOCONCENTRATION/BIOACCUMULATION
The log octanol/water partition coefficient (log P) of HEX has been
experimentally determined to be 5.04 (Wolfe et al., 1982) and 5.51 (Velth et
al., 1979), which Indicates a substantial potential for bloconcentration,
bloaccumulatlon and blomagnifIcation. Actual determinations of bloconcen-
tration and bloaccumulatlon In several aquatic organisms, however, Indicate
that HEX does not accumulate to a great extent (Podowski and Khan, 1979;
Velth et al., 1979; Spehar et al., 1979; Lu et al., 1975).
1812A 5-23 12/27/83
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Podowski and Khan (1979) conducted several experiments concerning the
uptake, bloaccumulatlon and elimination of 14C-HEX 1n goldfish (Carassius
auratus) and concluded that the species eliminated absorbed HEX rapidly. In
one experiment, fish were transfered dally Into fresh solutions of 14C-HEX
for 16 days. Nominal HEX concentrations of 10 pg/s, resulted 1n measured
water concentrations (based on radioactivity) 1n the range of 3.4-4.8
vg/S., because of rapid volatilization of the compound. Radioactivity
accumulated rapidly 1n fish tissue, reaching a maximum on day 8 correspond-
ing to ~6 mg HEX/kg. Since an undetermined amount of the radioactivity was
present as metabolites, no bioconcentratlon factor can be calculated. From
day 8 to day 16, tissue levels declined 1n spite of daily renewal of expo-
sure solutions, Indicating that excretion of HEX and/or Us metabolites was
occurring more rapidly than uptake. In a static exposure to an Initial
measured HEX concentration of 5 jjg/8., radioactivity was taken up by the
fish to a level corresponding to 1.6 mg HEX/kg on day 2, accompanied by a
slight decrease of HEX 1n the water. By day 4, -50% of the absorbed acti-
vity had been excreted, and the water level Increased. Over the following
12 days, radioactivity in both water and fish declined slowly.
Podowski and Khan (1979) also studied elimination, metabolism and tissue
distribution of HEX Injected into goldfish and concluded that goldfish
eliminate absorbed or injected HEX both rapidly and linearly (biological
half-life ~9 days). F1sh (27-45 g) were injected with 39.6 vg of
14C-HEX and analyzed 3 days later. Of the 97% of the radlolabeled dose
accounted for, -18.9% was eliminated by the fish, leaving a residual of
78.1%. Of the residue found in the fish, 47.2% was extractable 1n organic
solvent (little of the radlolabeled material could be Identified as HEX,
1812A 5-24 12/27/83
-------
which Indicated that blotransformatlon had occurred); 10.6% was watersoluble
metabolites; and 20.3% was unextractable. None of the metabolites were
Identified.
In the final experiment, residual activity 1n several fish tissues was
assayed 2, 4, 6 and 8 days following an Injection of 38.4 pg/flsh of
14C-HEX. Results showed activity corresponding to 0.2 and 0.3 mg HEX/kg
in the spinal cord and gills, respectively. These concentrations were
constant throughout the 8-day period of the study. Residues 1n the kidneys
and bile Increased within the same period from 1-3 and 0-32 mg/kg, respect-
ively, Indicating elimination via these routes. The authors stated that the
Increase was probably from enhanced conversion of the parent compound into
polar products suitable for elimination. In the other tissues, all residual
levels dropped leaving only the liver with levels >1 mg/kg (Podowskl and
Khan, 1979). The authors did not Identify the metabolites.
Velth et al. (1979) determined the bloconcentratlon factor (BCF) for HEX
to be 29 1n the fathead minnow (Plmephales promelas). In a 32-day flow-
through study, 30 fish were exposed to HEX at a mean concentration of 20.9
pg/8, and were sacrificed five at a time for residue analysis at 2, 4, 8,
16, 24 and 32 days. The study was conducted using Lake Superior water at
25°C (pH 7.5, dissolved oxygen >5.0 mg/8, and hardness 41.5 mg/s. as
CaC03). On the basis of Us estimated octanol/water partition coefficient
alone (log P = 5.51), a BCF of -9600 would have been predicted. However,
HEX did not bloconcentrate substantially, and therefore deviated from the
log Prlog BCF relationship shown for most of the other 29 chemicals tested
by these researchers.
Spehar et al. (1979) conducted a 30-day early-life-stage, flowthrough
toxldty test at 25°C with the fathead minnow (P. promelas). HEX residues
1812A 5-25 12/27/83
-------
1n the fish after 30 days of continuous exposure to HEX were <0.1 mg/kg for
all concentrations tested (0.78-9.1 yg/fc), and the BCF was <11 (0.1
mg/kg 1n fish divided by 9.1 pg/8. 1n water). In addition, toxldty
results Indicated that a median lethal threshold (or Incipient LC5 ) was
attained within 4 days. The authors concluded that the rapid attainment of a
threshold toxldty level and the low BCF Indicate that HEX 1s noncumulatlve.
Lu et al. (1975) studied the fate of HEX 1n a model terrestrial-aquatic
ecosystem maintained at 26.7°C with a 12-hour photopeMod. The model eco-
system consisted of 50 sorghum (Sorghum vulgare) plants (3-4 Inches tall) 1n
the terrestrial portion; 10 snails (Physa sp.), 30 water fleas (Daphnla
magna), filamentous green algae (Oedogonlum cardlacum) and a plankton cul-
ture were added to the aquatic portion. The sorghum plants were treated
topically with 5.0 mg of 14C-HEX 1n acetone to simulate a terrestrial
application of 1.0 Ib/acre (1.1 kg/ha). Ten early-f1fth-1nstar caterpillar
larvae (Estlgmene acrea) were placed on the plants. The Insects consumed
most of the treated plant surface within 3-4 days. The feces, leaf frass
and the larvae themselves contaminated the moist sand, permitting distri-
bution of the radlolabeled metabolites by water throughout the ecosystem.
After 26 days, 300 mosquito larvae (Culex plplens qulnquef asdatus) were
added to the ecosystem, and on day 30, three mosquito fish (Gambusla
aff1n1s) were added. The experiment was terminated after 33 days, and the
various parameters were analyzed. The radioactivity was then extracted from
water with dlethyl ether and from organisms with acetone. The results of
1LC analysis of the extracts are presented 1n Table 5-4. Data were not
reported for Daphnla or the salt marsh caterpillar. Uptake In this experi-
ment occurred through food as well as water, and therefore 1s termed bloac-
cumulatlon rather than bloconcentratlon. Lu et al. (1975) used the term
ecological magnification (EM) to designate the bloaccumulatlon factor (BAF).
1812A 5-26 12/27/83
-------
TABLE 5-4
Relative Distribution of HEX and Its Degradation Products3
14C-HEX Equivalents (ppm)
Mosquito
Water Alga Snail Larva F1sh
{mg/kg) (mg/kg) (mg/kg) (mg/kg)
HEX 0.00024 0.0818 0.3922 0.2230 0.1076
Other extractable compounds 0.00204 0.1632 0.3824 0.2542 0.1542
Total extractable 14Cb 0.00228 0.2450 0.7746 0.4772 0.2618
Unextractable 1AC 0.00750 0.0094 0.0814 0.0104 0.0982
Total "C& .0.00978 0.2544 0.8560 0.4876 0.3600
aSource: Lu et al., 1975
bUnder!1nes Indicate summation
1812A
5-27
12/27/83
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BAF for HEX 1n fish was 448 (0.1076 mg/kg 1n fish divided by 0.24
In water) for the 3-day exposure period, Indicating a moderate potential for
concentration (Kenaga, 1980). BAF 1n algae (<33-day exposure), snails
(<33-day exposure) and mosquito larvae (7-day exposure) was reported to be
341, 1634 and 929, respectively (Lu et al., 1975).
B1omagn1f1cat1on, measured as the ratio of HEX residues between trophic
levels (e.g., snail/algae or f1sh/mosqu1to), was far less substantial than
bloconcentratlon. Based on the HEX tissue residues, the snail/algae ratio
was 0.3922/0.0818 -- 4.8 and the fish/mosquito ratio was 0.1076/0.2230 = 0.48.
Lu et al. (1975) also studied the metabolism of HEX by the organisms
present 1n the model terrestrial-aquatic ecosystem. None of the products
were Identified except for HEX. The authors reported that unmetabollzed HEX
represented large percentages of the total extractable 14C, being 33% 1n
algae, 50% 1n snail, 46% 1n mosquito and 41% 1n fish. Percent blodegrada-
tlon was calculated for each organism [(unextractable 14C x 100)/total
14C] and reported to be: 4% for the alga (1n <33 days); 10% for the snail
(in <33 days); 2% for the mosquito (1n 7 days); and 27% for the fish (1n 3
days). However, these values may underestimate the extent of metabolism,
since acetone extractable polar compounds were not considered 1n the calcu-
lations.
Velslcol Chemical Corporation (1978) conducted fish tissue residue
studies below their Memphis, TN facility and reported that HEX was not
detected 1n either catfish or carp, although chlorinated compounds were
detected 1n the fish tissue. The possible source of these other compounds
was not discussed. In a joint federal and state study of the Mississippi
River above, around and below Memphis, Bennett (1982) of the U.S. EPA
reported that HEX was not detected 1n any of the eight fish sample groups
analyzed by GC/MS.
1812A 5-28 12/27/83
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In contrast to the above-described findings, fish collected from the
stream In the vicinity of the Hooker chemical plant discharge 1n Montague,
Michigan, were reported to contain 4-18 pg/kg of HEX 1n the edible fil-
lets. However, there was some question as to whether the analyzed compound
was HEX or a degradation product (Swanson, 1976).
5.4. SUMMARY AND CONCLUSIONS
The fate and transport of HEX 1n the atmosphere 1s not well documented,
but available Information suggests that the compound does not persist.
Cupltt (1980) estimated Us tropospheMc residence time to be ~5 hours, with
photolysis and reaction with hydroxyl radicals and ozone being the key
degradatlve processes. However, atmospheric transport of HEX from an area
of stored wastes has been demonstrated, at least for a short distance
(Peters et al., 1981).
In water, HEX 1s likely to dissipate rapidly by means of photolysis,
hydrolysis and blodegradatlon. In shallow water (a few centimeters deep),
HEX has a photolytlc half-life of -0.2 hours (Butz et al., 1982; Wolfe et
al., 1982). In deeper water where photolysis 1s precluded, hydrolysis and
blodegradatlon should become the key degradatlve processes when there 1s
little movement from the system. The hydrolytlc half-life of HEX Is several
days, and 1s not strongly affected by pH 1n the environmental range (5-9),
by salinity or by suspended solids (Yu and Attallah, 1977a; Wolfe et al.,
1982). Blodegradatlon may also be a significant process 1n certain waters
(Tabak et al., 1981), although the evidence Is weak. HEX is known to vola-
tilize from water (Kllzer et a"!., 1979; Weber, 1979). It 1s possible that
volatilization 1s limited by diffusion, particularly 1n waters that are not
well mixed, and by sorptlon on sediments.
1812A 5-29 12/27/83
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The fate and transport of HEX 1n soils are affected by Its strong ten-
dency to adsorb onto organic matter (Kenega and Goring, 1980; Wolfe et al.t
1982; Weber, 1979). HEX is predicted to be relatively Immobile in soil
based on its high log P value (Brlggs, 1973). Volatilization, which is
likely to occur primarily at the soil surface, is Inversely related to the
organic matter levels and water-holding capacity of the soil (Kllzer et al.,
1979). Leaching of HEX by groundwater should be very limited, and chemical
hydrolysis and microblal metabolism are expected to reduce environmental
levels. HEX 1s metabolized by a number of unidentified soil microorganisms
(Rieck, 1977b,c; Thuma et al., 1978).
The b1oconcentrat1on/b1oaccumulat1on/b1omagnif1cat1on potential of HEX
would appear to be substantial based on its high log P value (Wolfe et al.,
1982). BAFs derived from a short-term model ecosystem study appear to indi-
cate a moderate accumulation potential for algae (BAF = 341), snails (1634),
mosquito larvae (929) and mosquito fish (448). However, the compound did
not substantially biomagnlfy from algae to snails or from mosquito larvae to
fish (Lu et al., 1975). In addition, steady-state bloconcentratlon factors
(BCFs) in fish, measured 1n 30-day flowthrough exposures to constant levels
of HEX, were only 29 and <11, respectively (Velth et al., 1979; Spehar et
al., 1979). Metabolism and excretion of HEX by goldfish were demonstrated
by Podowskl and Khan (1979).
1812A 5-30 12/27/83
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6. ECOLOGICAL EFFECTS
The effects of HEX have been reported for several aquatic organisms,
Including Invertebrates and fish from freshwater and saltwater environments
and saltwater algae. The bloconcentratlon potential of HEX In aquatic
organisms and ecosystems has also been studied; these data have been dis-
cussed In Section 5.3. Ihe effects on microorganisms have been examined to
some degree. However, few studies have been located which describe the
effects of HEX on terrestrial plants or vertebrates.
6.1. EFFECTS ON AQUATIC ORGANISMS
6.1.1. Freshwater Aquatic Life.
6.1.1.1. ACUTE TOXICITY — Several studies are available on the
effects resulting from exposure of freshwater aquatic life to various con-
centrations of HEX.
Two studies have reported the acute toxldty of HEX 1n D. magna (Bucca-
fusco and LeBlanc, 1977; Vllkas, 1977). The results are shown 1n Table 6-1.
The 48-hour LC value ranged from 39-52 yg/l, and the 48-hour no-
effect level ranged from 18-32 vg/i. In the study by VHkas (1977),
routine water quality parameters were also analyzed. Results showed that
the pH values, determined Initially and after 48 hours, Increased with an
Increase 1n HEX concentration.
Results from acute toxlclty tests with HEX have been reported for a
number of freshwater fish species (Table 6-1). The 96-hour LCcn value for
bU
fathead minnow larvae In a flowthrough test with measured toxicant concen-
trations was 7 yg/fc (Spehar'et al., 1977, 1979). Values obtained with
adult fathead minnows 1n static tests with unmeasured toxicant concentra-
tions ranged from 59-180 yg/a (Henderson, 1956; Buccafusco and LeBlanc,
1977). Reported 96-hour values for goldfish, channel catfish and bluegllls
1813A 6-1 12/20/83
-------
CD
03
TABLE 6-1
Acute ToxUHy Data for Freshwater Species Exposed
LCso (ug/i^
cr<
i
IV
o
^.
CO
GO
Species
Cladoceran
Daphnla maqna
Cladoceran
Daphnla magna
Fathead minnow (larvae, <0.1 g)
Plmephales promelas
Fathead minnow (1-1.5 g)
Plmephales promelas
Fathead minnow (0.72 g)
Plroephales promelas
Goldfish
Carasslus auratus
Channel catfish (2.1 g)
Ictalurus punctatus
Blueglll (0.45 g)
Lepomls macrochlrus
Blueglll (8-13 cm)
Lepomls macrochlrus
Largemouth bass (8-13 cm)
Mlcropterus salmoldes
aS = static, FT = flowthrough, U
bNumbers 1n parentheses give 95X
Hethoda
24-hour
S,U 93.0
(78.9-109.6)
S.U 130
(68-260)
FT.M NR
S.U 115
93
75
S.U 240
(170-320)
NR NR
S,U 190
(140-250)
S.U 170
(140-210)
S.U >500,000
S.U >500.000
48-hour
52.2
(44.8-60.9)
39
(30-52)
NR
no
78
59
210
(180-250)
NR
150
(130-180)
150
(120-180)
30,000
35,000
Acute No-Effect
Concentration
96-hour
NO 32
ND 18
7.0 3.7
104 NR
78 NR
59 NR
180 87
(160-220)
78 NR
97 56
(81-120)
130 65
(110-170)
25,000 NR
20,000 NR
to HEX
Comments
17°C, soft water
22°C. soft water
25°C. soft water
Hard water, acetone soln.
Soft water, acetone soln.
Hard water, emulsion
(no acetone)
22°C, soft water
No details given
22°C, soft water
22°C, soft water
Water aerated during test
Hater aerated during test
Reference
VHkas, 1977
Buccafusco and LeBlanc.
1977
Spehar et al., 1977.
1979
Henderson, 1956
Buccafusco and LeBlanc,
1977
Podowskl and Khan, 1977
Buccafusco and LeBlanc,
1977
Buccafusco and LeBlanc,
1977
Davis and Hardcastle,
1957
Davis and Hardcastle.
1957
= unmeasured concentrations, M = measured concentrations
confidence Interval
-------
were also within this range (Podowskl and Khan, 1979; Buccafusco and
LeBlanc, 1977). Anomalously high values for blueglll (25,000 vg/a) and
largemouth bass (20,000 vg/!l), well above the solubility limit of 800-
2100 pg/B, (see Section 3.2.1.), were reported by Davis and Hardcastle
(1957) (see Table 6-1). These results could be high due to the failure to
properly disperse the toxicant 1n the test water (no carrier was mentioned),
and/or to volatilization of the compound, since the water was aerated during
the test.
S1nhasen1 et al. (1982) have recently reported biological effects of HEX
In rainbow trout exposed to 130 yg/ft. HEX In a nonredrculatlng flow-
through chamber. Oxygen consumption, measured polarographlcally, Increased
by 193% within 80 minutes and then gradually decreased until death, 1n ~5
hours. Vehicle controls showed no effects after 76 hours of exposure. HEX
added to normal trout mitochondria Increased basal oxygen consumption. The
authors concluded that HEX uncoupled oxldatlve phosphorylatlon.
6.1.1.2. SUBCHRONIC/CHRONIC TOXICITY -- Spehar et al. (1977, 1979)
conducted 30-day early life stage flowthrough toxldty tests with fathead
minnows (P. promelas). Tests were performed with measured concentrations
and were Initiated with 1-day-old larvae. The 96-hour LC value was
reported In the preceding section. The 96-hour mortality data Indicated a
sharp toxldty threshold, such that 94% survival was observed at 3.7
vg/a, 70% at 7.3 Mg/il, and 2% at 9.1 yg/t. At the end of the
30-day exposure period, mortality was only slightly higher, with 90% survi-
val at 3.7 Wg/Ji, 66% at 7.3 vg/t, and 0% at 9.1 yg/8.. These
results Indicated that the median lethal threshold, the lowest concentration
causing 50% mortality, was attained within 4 days. In addition, the HEX
residues found In fathead minnows during the end of the 30-day tests were
1813A 6-3 12/20/83
-------
low {<0.1 pg/g) and the BCF value was reported to be <11 (Spehar et al.,
1979). The authors concluded that the toxlclty data and BCF values
Indicated that HEX was noncumulatlve 1n fish; I.e., did not bloconcentrate
In fish as a result of continuous low-level exposure to HEX. The growth
rate of surviving larvae, measured as both body length and weight, did not
decrease significantly at any of the concentrations tested, compared with
the controls. This was true even at 7.3 yg/l, a level greater than the
calculated LC value. Based on these toxldty and growth data, Spehar et
al. (1977, 1979) concluded that 3.7 wg/l was the highest concentration
of HEX that produced no adverse effects on fathead minnow larvae. Thus, the
maximum acceptable toxicant concentration (MATC) was In the range of 3.7-7.3
vg/l. No other chronic toxldty data for any freshwater species were
located.
6.1.2. Marine and EstuaMne Aquatic Life.
6.1.2.1. ACUTE TOXICITY — Walsh (1981) reported unpublished data on
the effects of HEX on four species of marine algae, derived according to the
method described by Walsh and Alexander (1980). The 7-day EC was calcu-
lated as the concentration causing 50% decrease In blomass compared with the
control, as estimated by absorbance at 525 nm. The 7-day EC values
reported Indicated a wide range of susceptibility between the species
tested. Isochrysls galbana and Skeletonema costatum were the most suscep-
tible species, and the average 7-day EC™ values reported were about 3.5
and 6.6 yg/l, respectively. The average value for Porphyrldlum cruentum
was 30 yg/a, while that for Dunallella tertlolecta was 100 yg/8..
Other tests with S. costatum Indicated that the direct, alglcldal effect of
HEX was less pronounced than Us effect on growth. After 48 hours of expo-
sure to HEX at 25 yg/J., mortality, as Indicated by staining and cell
enumeration, was only 4% (Walsh, 1983).
1813A 6-4 12/20/83
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Among marine Invertebrates, the 96-hour LC5Q values for HEX ranged
from 7-371 yg/a (Table 6-2) (U.S. EPA, 1980a). Except where Indicated,
these results were from static tests with nominal concentrations of HEX.
The organism exhibiting by far the highest LC5Q was the polychaete,
Neanthes arenaceodentata. which Is an Infaunal organism living 1n the sedi-
ment. The two shrimp species tested were more sensitive to HEX by a factor
of 10 or more.
The static LC value reported by U.S. EPA (1980a) for the grass
shrimp, Palaemonetes puqlo. was slightly higher than that for the mysld
shrimp, Hys1dops1s bahla (see Table 6-2). However, the LC for the mysld
shrimp was considerably lower 1n a flow-through test than 1n the static
test. Similarly, the LC5Q value was lower when calculated from actual
measurements of HEX concentrations In the test solutions (measured concen-
tration) than when calculated according to the concentrations based on
amounts originally added to test solutions (nominal concentrations).
The acute toxldty values for HEX were comparable for each of three
marine fish species tested (U.S. EPA, 1980a). The static 96-hour LC5Q
values based on unmeasured concentrations for spot, sheephead minnow and
plnflsh varied only from 37-48 yg/8. (see Table 6-2).
6.1.2.2. CHRONIC TOXICITY — In an unpublished study (U.S. EPA,
1981), groups of 40 mysld shrimp were exposed for 28 days to measured, flow-
through concentrations of HEX. From the data shown 1n Table 6-3, measured
concentrations were about one-half of nominal. Mortality occurred 1n all
concentrations except the control, but showed no consistent dose-response
relationship. Fecundity, however, was more clearly related to dose.
Neither parameter was significantly affected at 0.30 yg/a, whereas both
were significantly affected at 0.70 yg/l (Table 6-3). Thus, the MATC
for this organism was between these two values.
1813A 6-5 12/20/83
-------
TABLE 6-2
Acute Toxldty Data on Marine Organisms Exposed to HEX3
Species
Polychaete
Neanthes arenaceodentata
Grass shrimp
Palaemonetes puglo
Mysld shrimp
Mys1dop1s bahla
Mysld shrimp
Mys1dop1s bahla
Mysld shrimp
Mys1dop1s bahla
P1nf1sh
Laqodon rhomboldes
Spot
Lelostomus xanthurus
Sheepshead minnow
Cyprlnodon varlegatus
Method6
S,U
S,U
S,U
FT.U
FT.M
S,U
S,U
S,U
96-hour LC50C
(ng/D
371
(297-484)
42
(36-50)
32
(27-37)
12
no-131
7
(6-8)
48
(41-58)
37
i 30-421
45
(34-61)
aSource: U.S. EPA, 1980a
&M = measured concentrations; S = static; FT = flowthrough; U - unmeasured
concentrations
C95% confidence Interval
1813A 6-6 12/20/83
-------
TABLE 6-3
Effects of 28 Days Exposure of Mysld Shrimp, Mys1dops1s bahla. to HEX3
Concentration (yg/l)
Nominal
Control
0.75
1.5
3.0
6.0
12.0
Measured
ND
0.30
0.70
3.0
2.9
6.2
Mortality
(X)
0
18.9
43. 6b
18.4
23.1
97. 5b
Total
Offspring
195
167
67
79
72
0
Offspring
per Female
15.7
11.6
5.0b
5.4b
5.5b
Ob
aSource: U.S. EPA, 1981
bS1gn1f1cantly different from the control (p<0.05)
ND = Not detected
1813A 6-7 12/20/83
-------
No other data were located on the chronic toxlclty of HEX to saltwater
organisms.
6.2. EFFECTS ON OTHER ECOSYSTEMS
The effects of HEX on microorganisms 1n aqueous and soil systems have
been tested. Many of the aqueous concentrations tested exceeded the upper
limit of aqueous solubility of 0.8-2.1 mg/l; these concentrations usually
were achieved by use of an organic solvent. Thus the environmental signifi-
cance of the results must be Interpreted with caution.
Cole (1953) Inoculated 10 strains of common human and animal pathogens
Into growth media containing various concentrations of HEX. The Inhibiting
concentration, or lowest concentration In which no growth was observed after
96 hours of contact, ranged from 1-10 mg/B, HEX. Addition of 5 or 10
mg/8, of HEX to sewage effluent Inoculated with Salmonella typhosa was also
found to be more effective than similar concentrations of chlorine In reduc-
ing total bacterial count, conforms and S. typhosa (Cole, 1954). Yowell
(1951) also reported In a patent application that HEX has antibacterial
properties; standard phenol coefficients for E_. typhus (sic) and Staphy-
lococcus aureus were 25 and 33, at 21 and 23 ppm of HEX, respectively.
These findings Indicated that concentrations of HEX at or slightly above Us
aqueous solubility limit were toxic to several types of pathogens.
In contrast, tests with other microorganisms have shown some ability to
withstand HEX exposure. Twenty-three strains of organisms (type unspeci-
fied), when added to aqueous medium containing HEX at 1000 mg/l, were able
to metabolize the compound to a varying degree. Analysis of the medium
after 14 days Indicated a HEX removal of 2-76%, depending on the organism
used (Thuma et al., 1978).
1813A 6-8 12/20/83
-------
Rleck (1977a) found no effects on natural populations of bacteria, actl-
nomycetes and fungi after 24 days Incubation of a sandy loam soil treated
with 1 or 10 yg/g (dry weight) HEX. He concluded that no significant
detrimental effects on mlcroblal populations would result from treatment of
soils with these levels of HEX.
The effects of HEX on three ecologically Important mlcroblal processes
were recently reported by Velslcol (Butz and Atallah, 1980). Results on
cellulose degradation by the fungus Trlchoderma Iong1brach1atum Indicated
that a suspension of HEX Inhibited cellulose degradation at a concentration
of 1 mg/a and higher 1n a liquid medium. The calculated 7-day EC was
1.1 mg/a. Extrapolations for the 1- and 3-day EC5_ values were reported
to be 0.2 mg/a. The decrease 1n toxlclty In the 7-day period was attri-
buted to adaptation by T. longlbrachlatum.
HEX Inhibited anaerobic sulfate reduction by Desulfov1br1o desulfurlcans
when present In suspension 1n a liquid medium. Following a 3-hour contact
period, growth Inhibition was observed at HEX concentrations of 10-100
mg/a, and no growth was evident at 500 and 1000 mg/a. Similarly, growth
Inhibition was observed at 1 and 10 mg/a following a 24-hour contact
period, and no growth was evident at 50-1000 mg/a. HEX was considered
slightly toxic to D. desulfurlcans (Butz and Atallah, 1980).
A third study by the same Investigators (Butz and Atallah, 1980) focused
on the effects of HEX on urea ammonlflcation by a mixed mlcroblal culture 1n
moist soil. The results Indicated that HEX concentrations of 1-100 yg/g
(dry weight) were not toxic to soil organisms responsible for urea ammon1f1-
catlon. EC Increased from 104 wg/g at 1 day to 1374 yg/g at 14
days. The authors suggested that the low toxldty and Us decrease over
time In this experiment may have been due to adsorption of the toxicant onto
1813A 6-9 12/20/83
-------
soil particles, as well as to potential adaptation by the organism. Soil
adsorption may also account for the lack of toxlclty 1n the test by Relck
(1977a).
6.3. EFFECTS ON TERRESTRIAL VEGETATION
In a patent application, HEX was reported to be nontoxlc to plants 1n
concentrations at which 1t was an effective fungicide (Yowell, 1951). Test
solutions were prepared by adding HEX at various proportions to attaclay and
a wetting agent, and the mixture was then mixed with water. The concentra-
tions of HEX applied to plants as an aqueous spray were 0.1, 0.2, 0.5 and
1.0%. Slight Injury (unspecified) to Coleus blumel was reported at 1.0%
HEX, whereas lower concentrations were not harmful. Similarly, HEX was
added to horticultural spray oil and an emulslfler at various proportions
and then mixed with water. The concentatlons of HEX In the prepared spray
were 0.25 and 0.5%. No Injury to £. blumel was observed at these concentra-
tions.
6.4. EFFECTS ON WILDLIFE
No data were available on the effects of HEX on amphibians, reptiles or
birds, or on mammals other than those typically utilized 1n laboratory
testing.
6.5. SUMMARY
The toxlclty of HEX to several forms of aquatic life has been demon-
strated. The freshwater cladoceran Daphnla maqna gave 48-hour LC™ values
of 39 and 52 pg/8. In static tests (Buccafusco and LeBlanc, 1977; Vllkas,
1977). Freshwater fish species tended to be slightly more tolerant, with
96-hour LC50 values ranging from 59-180 yg/l (Henderson, 1956; Bucca-
fusco and LeBlanc, 1977; Podowskl and Khan, 1977). However, when fathead
minnow fry (larvae) were tested 1n a flowing system, a value of 7 yg/8,
was obtained (Spehar et al., 1977, 1979).
1813A 6-10 01/19/84
-------
Saltwater crustaceans were of similar sensitivity as D. magna In static
tests; 96-hour LCr. values for two shrimp species were 32 and 42 yg/H,
DU
while a polychaete was more resistant with a value of 371 yg/fc. How-
ever, a flowthrough test with mysld shrimp gave a 96-hour LC of 7
yg/l. Three saltwater fish species all had static LC values within
the range of 37-48 vg/8. (U.S. EPA, 1980a).
The chronic MATC for the fathead minnow, based on a 30-day early-
Hfestage test, was between 3.7 and 7.3 yg/l, as was the acute LC
(Spehar et al., 1977, 1979). Thus no cumulative toxic effect was observed,
and there was also no accumulation of residues of HEX. Fish growth was
unaffected In this test. On the other hand, a 28-day chronic test with
mysld shrimp gave an MATC between 0.30 and 0.70 yg/8., well below the
acute value of 7 yg/l for this species. Both survival and fecundity
were reduced by toxicant exposure (U.S. EPA, 1981).
In the only tests conducted with aquatic plants, two of four saltwater
unicellular algal species tested were of comparable sensitivity as crusta-
ceans, with 7-day EC__ values of 3.5 and 6.6 yg/1, respectively. The
other species were somewhat more tolerant (Walsh, 1981).
In general, flowing toxicant concentrations produced a greater response
than static concentrations, and measured concentrations were found to be
about one-half of nominal concentrations. Thus static tests, all based on
nominal concentrations, probably underestimated HEX toxldty. Tests Ini-
tiated with other than newborn animals could also have underestimated the
toxic response of natural populations exposed to HEX.
In aqueous media, HEX 1s toxic to many microorganisms at nominal concen-
trations of 0.2-10 mg/i, or levels substantially higher than those needed
to kill most aquatic animals or plants (Cole, 1953, 1954; Yowell, 1951).
1813A 6-11 12/20/83
-------
Some microorganisms are able to withstand exposures as high as 1000 mg/ft
(Thuma et al., 1978). HEX appears to be less toxic to microorganisms In
soil than 1n aquatic media, probably due to adsorption on the soil matrix
(R1eck, 1977a; Butz and Atallah, 1980).
Sufficient Information Is not available to determine the effects of HEX
exposure on terrestrial vegetation or wildlife, although data from labora-
tory studies summarized 1n the following sections could be used to estimate
effects on wild mammals.
1813A 6-12 12/20/83
-------
7. TOXICOLOGY AND HEALTH EFFECTS
7.1. PHARMACOKINETICS
7.1.1. Absorption, Distribution, Metabolism and Excretion.
7.1.1.1. ORAL — Mehendale (1977) studied the absorption, metabolism,
excretion and tissue distribution of HEX 1n 225-250 g male Sprague-Dawley
rats. A single dose of 6 mg/kg 14C-HEX In corn oil was given by oral
gavage. The animals were maintained In metabolism cages for 7 days. Urine
and fecal samples were collected dally. After 7 days, the rats were sacri-
ficed and the amount of radlolabel In major organs, urine and powdered feces
was determined. Ten percent of the radlolabel was recovered In the feces
and 33% 1n the urine during the 7 days while only trace amounts were found
In the liver, kidney and other major organs. Since >50% of the administered
dose was not accounted for, the author felt that the respiratory tract was
the major route of excretion for orally administered HEX. [Another Inter-
pretation of these results Is that HEX and/or Us metabolites were volati-
lized and lost during sample preparation, I.e., powdering of the feces,
before analysis (WhHacre, 1978)]. Mehendale also studied the subcellular
distribution of radlolabel 1n cellular fractions of rat liver and kidney
following oral administration of 14C-HEX. In both organs, the majority of
radlolabel was located 1n the cytosol. Specific metabolites and the meta-
bolic form of the radlolabel In various fractions and samples were not
Identified In these studies.
In 1979, Dorough studied the absorption, tissue distribution and excre-
tion of HEX In male and female Sprague-Dawley rats (200-250 g) and mice
(strain not specified; 25-30 g). The animals were divided Into two com-
parable groups and were given a single oral dose of 2.5 or 25 mg/kg of
1AC-HEX (vehicle not specified). The animals were placed In metabolism
0849A 7-1 12/30/83
-------
cages equipped with a trap to collect expired organocompounds and a trap to
collect expired carbon dioxide. Less than 1% of the radlolabel was trapped
In the expired gases over a 3-day period. The pattern of results for other
routes of elimination was similar In both sexes of each species. After 3
days, animals given 2.5 mg/kg excreted an average of 68% of the radlolabel
1n the feces and 15% In the urine while animals given 25 mg/kg excreted an
average of 72% of the radlolabel In the feces and 14% In the urine. Total
recovery of radlolabel was between 83 and 86%. Thus, 14-17% of the radlo-
label was not accounted for In this study. In addition, Dorough fed 1, 5 or
25 ppm HEX to rats and mice for a maximum of 30 days. During this study,
54-70% of the radlolabel was excreted In the feces and 6-12% In the urine.
Ihe total cumulative recovery of radlolabel ranged between 63 and 79% with
average values of 72% recovery. This means that an average of 28% of the
radlolabel was not accounted for. Metabolites were not Identified In these
studies.
In a study by Yu and Atallah (1981), male and female Sprague-Dawley rats
(240-350 g) were given a single dose of 3 or 6 mg/kg 14C-HEX 1n 0.5 mft
corn oil by oral gavage. Radioactivity appeared 1n the blood within 30
minutes, reached a maximum value at 4 hours, and then gradually decreased.
WHhln 48 hours, 70% of the radlolabel was excreted In the feces and 17% in
the urine while only a total of 2.8% was retained In the liver, kidneys,
fat, muscle, brain and heart. Thus, -90% of the radlolabel was recovered In
this study. Metabolites were not Identified 1n this study although the
authors stated that no unchanged HEX (I.e., HEX that was not metabolized or
bound to other molecules) was found In the excreta or tissues. When HEX was
Incubated with the contents of rat gut or with fecal homogenates, the esti-
mated half-life of unchanged HEX was 10.1 hours and 1.6 hours, respectively.
0849A 7-2 12/29/83
-------
On this basis, the authors Indicated that HEX was poorly absorbed In the gut
and that mlcroblal action was responsible for the metabolism of HEX.
7.1.1.2. DERNAL — There are no pharmacoklnetlc studies of HEX
Involving dermal application. Even though the kinetics of HEX absorption
through the skin are not known, HEX does react with and discolor the skin
following dermal exposure (Treon et al., 1955; IRDC. 1972) which may be an
Indication that HEX Is absorbed through the skin.
7.1.1.3. INTRAVENOUS — Mehendale (1977) studied biliary excretion
following Injection of 1 yC1 HEX (5ymole vehicle not Identified) Into
the femoral vein or artery In Sprague-Dawley rats whose common bile duct had
been cannulated. There was blexponentlal decay of radlolabel from the blood
with estimated half-lives of ~5 and 60 minutes. The metabolic forms of HEX
responsible for the blexponentlal decay were not Identified. Approximately
9% of the radlolabel was excreted 1n the bile 1n 1 hour.
Yu and Atallah (1981) Injected 0.25 mg/kg 34C-HEX (vehicle not Iden-
tified) Intravenously Into Sprague-Dawley rats. Within 48 hours, 21% of the
radlolabel was excreted In the feces and 18% In the urine while a total of
-28% of the radlolabel remained In the liver, kidneys, fat, muscle, brain
and heart. Metabolites were not Identified 1n this study and only 67% of
the dose was recovered.
7.1.1.4. INHALATION — In 1980, Dorough studied the absorption and
fate of inhaled HEX in female Sprague-Dawley rats (175-250 g). Animals were
exposed to vapors of 14C-HEX over a 1-hour period to achieve doses of -24
vg/kg body weight. Considerable difficulty was experienced In maintaining
the desired concentration of HEX throughout the exposure period. Approxi-
mately 69% of the radlolabel was recovered, with 13% in the body tissues,
23% in the feces, and 33% In the urine. Less than 1% of the Inhaled radio-
label was recovered in the expired air following exposure.
0849A 7-3 12/29/83
-------
These results were confirmed In a study by Lawrence and Dorough (1982)
In which female Sprague-Oawley rats (175-225 g) were exposed In a facemask
system for 1 hour to 24 v»g/kg 1AC-HEX. Following exposure, <1% of the
recovered radlolabel was expired as organocompounds and no detectable
14C-carbon dioxide was expired. The trachea and lungs contained the
highest levels of radlolabel with 107 and 74.5 ng equlvalent/g tissue,
respectively.
7.1.1.5. COMPARATIVE STUDIES — In the Inhalation studies of Dorough
(1980), Lawrence and Dorough (1982), and El Dareer et al. (1983), groups of
rats were given HEX by oral gavage and by Intravenous (i.v.) Injection 1n
order to compare the results for the three routes of administration. Tables
7-1, 7-2 and 7-3 respectively, summarize the results of these three studies.
The tissue distribution and route of elimination were different for the
three routes of administration. The results of the oral studies compare
quite favorably with the studies of Dorough (1979) and Yu and Atallah (1981).
El Dareer et al. (1983) completed a HEX disposition comparison study
using male Fischer 344 rats for the National Toxicology Program (NTP). HEX
(95-99% pure) was administered orally (4.1 and 61 mg/kg), Intravenously
(0.59 mg/kg) and by Inhalation (1.0 and 1.4 mg/kg). The disposition of
radioactivity from 14C-HEX In rats dosed by various routes 1s summarized
In Table 7-3. In this experiment after oral doses, most of the radioactiv-
ity appeared 1n the urine and feces within 72 hours. In comparison with the
i.v. route, the percentages found in the urine and feces were smaller with a
relatively large proportion of the radioactivity remaining In the tissues,
most 1n the liver and carcass. The rats exposed to the vapors had a higher
percentage remaining 1n the tissues as compared to oral dosing, but lower 1n
comparison to the I.v. route. Metabolitles were not identified in the study.
0849A 7-4 12/29/83
-------
o
CD
TABLE 7-1
Disposition of Radioactivity from 14C-HEX 1n Rats Dosed by Various Routes3
no
vO
00
CO
Oral
Feces
Urine
Tissues
C02
Other volatile
TOTAL RECOVERY
Low
79.4
35.5
2.4
0.8
0.2
118.0
Doseb
i 2
+ 2
± o
± o
± o
± 3
.9%
.5%
.6%
.0%
.0%
.0%e
High
65.3
28.7
2.4
0.6
0.3
97.0
Intravenousb
Doseb
± &
t 4
± o
± o
± o
+ 7
.9%
.2%
.1
.0
.0
.0%
34.0
15.8
39.0
0.1
0.1
89.0
i 1.0%d
± 1.4%
± i.ox
+ 0.0
1 0.0
i 2.0%
Inhalation
Group Ac
28.7 i 4.3%
41.0 ± 4.8%
28.9 + 1.6%
1.4 + 0.3
--
(100%)
Group
47.5 ±
40.0 +
11.5 +
1.0 +
--
8b
6.4%
6.6%
0.8%
0.5%
(100%)
aSource: El Dareer et al., 1983 (The values represent the mean % of dose i standard deviation for three
rats.
72 hours after dosing or exposure
°At 6 hours after exposure
dPlus Intestinal contents
eFor an unexplained reason, the total recovery for this dose was higher than theoretical. If the percent
recoveries for this dose are "normalized" to 100%, differences 1n disposition for the two doses are mini
mal, an indication that no saturable process is operative 1n this dose range.
-------
TABLE 7-2
Fate of Radiocarbon Following Oral, Inhalation and
Intravenous Exposure to 14C-HEX 1n Rats3
Oralb
Cumulative Percent of Dose
Intravenousc
Inhalat1ond
Urine
Feces
Urine
Feces
Urine
Feces
Body
Total
22.2
62.2
24.0
67.7
24.4
68.2
0.2
92.8
* 1.8
i 8.0
+ 1.9
1 5.1
i- 1.9
+ 5.1
f 0.2
* 4.7
24-Hour
18.3
21.1
48-Hour
20.7
30.4
72-Hour
22.1
47.4
15.7
85.2
+ 5.2
± 7.1
+ 5.6
± 1-7
+ 5.7
+ 1.9
*• 7.8
+ 4.8
29.7
17.0
32.5
21.0
33.1
23.1
12.9
69.1
* 4.5
± 7.5
+ 5.1
±7.5
4- 4.5
+ 5.7
+ 4.7
4- 9.6
aSource: Dorough, 1980, and Lawrence and Dorough, 1982
^Doses administered 1n 0.5 ml corn oil at 7 yg/kg body weight
°Doses administered In 0.2 ml 10:4:1 sa!1ne:propylene glycol:ethanol by
Injection Into the femoral vein at 5 yg/kg body weight
^Doses administered as vapors over a 1-hour exposure period to achieve doses
of -24 yg/kg body weight.
0849A
7-6
12/29/83
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TABLE 7-3
Distribution of HEX Equivalents3 In Tissues and Excreta of Rats
72 Hours After Oral, Inhalation and Intravenous Exposure to 14C-HEXb«c
Sample
Oral Dose
(6 mg/kg)d
Inhaled Dose
(24 yg/kg)
Intravenous Dose
(10 yg/kg)
Trachea
Lungs
Liver
Kidneys
Fat
Remaining carcass
ng/q of Tissue
292 * 170
420 +- 250
539 4- 72
3272 t 84
311 > 12
63 4- 40
107.0 4- 65.0
71.5 4- 55.2
3.6 f 1.9
29.5 4- 20.2
2.8 4- 0.4
1.3 + 0.6
3.3 4- 1.7
14.9 4- 1.1
9.6 4- 1.1
22.3 4- 0.6
2.3 + 0.2
0.5 4- 0.1
Percent of Dose
Whole Body
Urine
Feces
Total
2.
15.
63.
81.
8 4- 1
3 + 3
6 + 8
7+6
.1
.3
.5
.7
12.
33.
23.
69.
9
1
1
1
+
+
+
+
4.
4.
5.
9.
7
5
7
6
31
22
31
84
.0
.1
.4
.6
+ 7.8
+ 5.7
+ 1.9
+ 4.6
aOne HEX equivalent Is defined as the amount of radlolabel equivalent to
one nanogram of HEX based on the specific activity of the dosing solution.
bSource: Adapted from Dorough, 1980 and Lawrence and Dorough, 1982
CA11 values are the Mean *_ S.D. of three replicates.
dNote that the oral dose was 250 and 600 times that of the Inhaled and
1.v. doses, respectively. That was necessary since residues were not
detected 1n Individual tissues of animals treated orally at doses of 5-25
yg/kg.
0849A
7-7
12/29/83
-------
This study confirms Borough's studies In that the major routes of elimi-
nation are fecal and urinary. LHtle radioactivity appeared as 14C02 or
as other volatile compounds. Since little radioactivity was detected In the
exhaled air, the respiratory tract Is not a substantial factor In the dis-
position of HEX. This substantiates the findings of Lawrence and Dorough
(1981) and sheds doubt on the Mehendale (1977) conclusion. The radioactiv-
ity found In the urine, feces and body after 72 hours were similar to
Lawrence and Dorough (1981) with the exception of a higher percentage being
found In the feces than In the urine.
Even after reviewing these studies, the exact nature of HEX 1n the lung
tissue is not fully understood. Several observations have been made during
the development of this document and only further research can determine the
answer. During Inhalation and the passage of HEX through the lung tissue to
reach the blood, a conversion occurs to water-soluble compounds may occur
and HEX 1s eliminated through the kidneys. In contrast, an 1.v. dose may be
bound unchanged to blood components and remain attached until the liver,
whereupon It may be displaced and become associated with the liver tissue.
However, Lawrence and Dorough (1982) still conclude that regardless of the
route of HEX administration, damage to the lungs occurs and 1n all cases
appears to be the primary cause of death 1n the laboratory animals.
7.1.1.6. CONCLUSIONS REGARDING THE FATE OF HEX IN BIOLOGICAL
SYSTEMS — From the data presented 1n the pharmacoklnetic studies, the
following points can be made regarding the fate of HEX 1n biological systems:
HEX reacts with biological tissues and macromolecules at the
point of administration as Indicated by the following:
- the high concentration of HEX equivalents 1n the lung and
trachea following Inhalation exposure
- the short biological half-life of unchanged HEX when Incuba-
ted with the contents of rat gut or fecal homogenates (10.1
and 1.6 hours, respectively)
0849A 7-8 12/29/83
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HEX is not readily absorbed through the gastrointestinal tract
as Indicated by the following:
- the 2- to 3-fold higher fecal excretion of HEX equivalents
following oral administration as compared to Intravenous or
Inhalation administration
- the reactivity of HEX with the gastrointestinal contents as
Indicated by the fact that no unchanged HEX 1s excreted
following oral administration
HEX equivalents are not volatilized and lost 1n expired air
during the first 72 hours following dosing as Indicated by the
following:
- no measurable 14C-carbon dioxide was collected following
HEX administration by the Inhalation route; at most, only
trace amounts were collected following oral administration
- only trace amounts of radlolabel were collected 1n expired
air traps designed to collect HEX or Its organo-metabolHes
following HEX administration by the oral or inhalation route
Since the recovery of radlolabel following HEX administration varies
from 43% to >90% in the pharmacokinetlc studies reported, a need for a more
complete study of the pharmacodynamics of HEX by oral gavage and inhalation
exposure is evident. A major portion of the radlolabel may be "fixed" to
tissues at the site of administration and missed in routine recovery pro-
cedures for pharmacokinetics studies. No one has reported measuring the
amount of radlolabel in the stomach following oral gavage or in blood
vessels or capillary beds following intravenous injection.
The metabolic pathway of HEX 1s not understood because none of the
metabolites of HEX were identified. Therefore, a complete metabolism study
is essential before a valid comparison of the fate of HEX by various routes
of administration is possible.
7.1.2. Summary. Pharmacokinetic studies designed to determine the
absorption, distribution, metabolism and elimination of HEX In rats and mice
have involved the oral, Intravenous and Inhalation routes of administration
of 14C-HEX. The fecal excretion of radlolabel following oral dosing 1s
0849A 7-9 12/29/83
-------
2- to 3-fold higher than for 1.v. or Inhalation administration which
Indicates that HEX 1s not readily absorbed from the gastrointestinal tract.
Following Inhalation, considerable radlolabel remained In the lung and
trachea Indicating that HEX reacts with biological membranes and molecules
in vivo. HEX has also been shown to react with the contents of the gastro-
intestinal tract in vitro. Since up to 57% of the radlolabel has not been
accounted for even 1n studies 1n which considerable effort has been made to
recover all of the radlolabel, HEX might possibly react with biological mem-
branes and molecules at all sites of administration or membrane transport.
The fate of HEX 1n biological systems 1s not well understood because of the
failure to recover all or most of the radlolabel 1n these studies and the
failure to Identify the metabolites of HEX.
7.2. MAMMALIAN TOXICOLOGY
7.2.1. Acute Toxldty. The acute toxldty of HEX Is summarized 1n
Table 7-4. A complete toxldty table 1s also presented 1n Appendix 1.
7.2.1.1. ACUTE ORAL TOXICITY -- Treon et al. (1955) conducted a
series of oral toxldty studies using female rabbits (strain unspecified)
and Carworth rats of both sexes. HEX was administered as a 5% solution 1n
peanut oil via oral gavage. The oral LD for female rabbits Is -640
mg/kg. The oral LD™ for male and female rats Is -510 mg/kg and 690
mg/kg, respectively. In 1968, IRDC determined the oral LD5Q for albino
rats to be 926 mg/kg for HEX given 1n corn oil by oral gavage. In more
recent studies, Dorough (1979) reported the oral LD5Q for male and female
Sprague-Dawley rats to be -651 mg/kg and for male and female mice (strain
unspecified) to be greater than 600 mg/kg. Thus, HEX 1s moderately toxic
when given orally. Based on FIFRA guidelines (40 CFR 162.10) HEX, when
administered orally to young adult experimental animals, would be classified
0849A 7-10 12/29/83
-------
o
00
TABLE 7-4
Acute Toxlclty of HEX
r>o
*v
t\3
00
CO
Study/Reference
Oral LDso/
Treon et al. , 1955
Oral LDso/
Treon et al., 1955
Oral LDso/
IRDC, 1968
Oral LDso/
Dorough, 1979
Oral LDso/
Dorough, 1979
Oral LDso/
SRI 1980a
Oral LDso/
SRI, 1980a
Dermal LD$o/
Treon et al., 1955
Dermal LDso/
IRDC, 1972
Species/Age Material
Grade
Rat, young Technical
adult
RabbH, Technical
adult
Rat, young Technical
adult
Rat, young Technical
adult
Mouse, young Technical
adult
Rat, Technical
weanling
Mouse, Technical
weanling
RabbH, Technical
adult
RabbH, Technical
adult
Results
LDso: Males - 510 mg/kg
Females - 690 mg/kg
LDso: Females -
LDso: Males and
LDso: Males and
LDso: Males and
640 mg/kg
Females - 926 mg/kg
Females - 651 mg/kg
Females - 600 mg/kg
LDso: Males - 425 mg/kg
Females - 315 mg/kg
LDso: Males and
LDso: Females -
Females - 680 mg/kg
780 mg/kg
LDso: Males - 200 mg/kg
Females - 340 mg/kg
Toxlclty*
Category
III
III
III
III
III
III
II
II
III
II
II
II
-------
o
CD
Id
3>
TABLE 7-4 (cont.)
I
ro
ro
\
ro
Study/Reference
Inhalation LC$Q/
Treon et al., 1955
Inhalation LCso/
Rand et al., 1982
Inhalation LCso/
Treon et al., 1955
Inhalation LC$Q/
Treon et al., 1955
Inhalation LCso/
Treon et al., 1955
Primary Eye Irritation/
IROC, 1972
Primary Dermal Irritation/
Treon et al., 1955
Primary Dermal Irritation/
IRDC, 1972
Primary Dermal Irritation/
Treon et al.. 1955
Spedes/Age
Rat, young
adult
Rat, young
adult
Rabbit,
adult
Guinea pig,
young adult
Mouse,
adult
Rabbit,
adult
Rabbit,
adult
Rabbit,
adult
Monkey,
adult
Material
Grade
Technical
Technical
Technical
Technical
Technical
Technical
Technical
Technical
Technical
Results
3.5-hour LCsg: Males and Females -
3 . 1 ppm
4-hour LCso: Males - 1.6 ppm
Females - 3.5 ppm
3.5-hour LC50: Females - 5.2 ppm
3.5-hour LCso: Males and Females -
7.1 ppm
3.5-hour LCsg: Males and Females -
2.1 ppm
Severe eye Irritant (0.1 ma for
5 minutes or 24 hours) all dead by
day 9 of study
Moderate skin Irritant (250 mg/kg)
One application
Severe skin Irritant (200 mg/kg).
All males died 1n study
M1ld skin discoloration (0.05 mfc of
10% HEX solution)
Toxlclty*
Category
I
I
I
II
II
I
I
II
II
None
co *Accord1ng to the FIFRA guidelines, 40 CFR 162.10
-------
1n ToxIcHy Category III. In addition, Southern Research Institute (SRI,
1980a) reported the oral LDC.. for male and female weanling B,C0Fn
t>u b J I
mice to be 680 mg/kg. Also, SRI (1980a) reported the oral LD5Q for wean-
Ung Fischer 344 rats to be 425 mg/kg for males and 315 mg/kg for females.
7.2.1.2. ACUTE DERMAL TOXICITY — Treon et al. (1955) reported the
dermal LD5Q 1n female rabbits (strain unspecified) to be 780 mg/kg while
IROC (1972) reported the dermal LD 1n albino rabbits (strain unspeci-
fied) to be <200 mg/kg 1n males and to be 340 mg/kg In females. These data
would place HEX, when applied dermally, 1n ToxIcHy Category II.
7.2.1.3. ACUTE INHALATION TOXICITY — Treon et al. (1955) reported a
3.5-hour LC™ of 3.1 ppm for Carworth rats of both sexes. Rand et al.
(1982) reported a 4-hour LC50 of 1.6 ppm for male Sprague-Oawley rats and
3.5 ppm for female rats. Treon et al. (1955) determined the 3.5-hour L£cn
bU
to be 5.2 ppm 1n female rabbits, 2.1 1n male and female mice, and 7.1 1n
male and female guinea pigs. These concentrations are 1n the range of
0.02-0.08 mg/l for HEX vapor for rats and mice which would place HEX, when
Inhaled, 1n ToxIcHy Category I.
7.2.1.4. EYE IRRITATION — IRDC (1972) tested HEX for eye 1r1tat1on
by Instilling 0.1 ma HEX Into the eyes of New Zealand white rabbits for 5
minutes or 24 hours before washing. All rabbits died on or before the 9th
day of the observation period. HEX 1s a strong eye Irritant and would be 1n
ToxIcHy Category I based on ocular exposure.
7.2.1.5. DERMAL IRRITATION — Treon et al. (1955) reported HEX to be
a primary skin Irritant 1n rabbits (strain unspecified) at a dose level of
250 mg/kg. In 1972, IRDC reported HEX 1n albino rabbits (strain unspeci-
fied) to be a dermal Irritant based on lethality 1n males at 200 mg/kg and
severe Irritation 1n females at the same dose level. In this study, Intense
0849A 7-13 12/29/83
-------
discoloration of the skin was noted. These data would place HEX 1n Toxldty
Category II for dermal Irritation. In the Treon study, monkeys (strain
unspecified) were also tested and discoloration of the skin was noted even
at low doses (0.05 ml of 10% HEX).
7.2.1.6. SUMMARY — The acute oral toxldty of HEX has been studied
In rats, rabbits and mice. The oral LD™ for adult animals 1s >500 mg/kg
which places HEX 1n Toxldty Category III. The acute dermal toxldty of HEX
has been studied 1n rabbits and the dermal LD 1s >200 mg/kg which places
HEX 1n Toxldty Category II. The acute Inhalation toxldty of HEX has been
studied 1n rats, rabbits, guinea pigs and mice. In rats and mice, the
3.5-4.0 hour LC for HEX 1s <0.2 mg/8. which places HEX In Toxldty
Category I. In comparison, as Dorough has stated 1n the review of this
document, the pathological effects are observed 1n the lung no matter which
route of administration of HEX 1s used. In addition, HEX 1s a severe eye,
skin and pulmonary Irritant.
7.2.2. Subchronlc Toxldty.
7.2.2.1. SUBCHRONIC ORAL TOXICITY —
7.2.2.1.1. Range-Finding Studies — LUton B1onet1cs (1978b) deter-
mined the oral L0r of HEX In Charles River CD-I rats to be 76 mg/kg. When
b
the LOV was administered to these rats for 5 consecutive days, all rats
died within the 5-day period. In a range-finding study using groups of 5
male and 5 female Fischer 344 rats, SRI (1980a) reported no mortality at
doses of 25, 50 or 100 mg/kg when given 12 doses 1n 16 days. At 200 mg/kg,
and using the same dosing regime, 5 of 5 males and 4 of 5 females died, and
at 400 mg/kg, 5 of 5 males and 4 of 5 females died during the study. In the
same study, B,C3F, mice died when given doses of 400 or 800 mg/kg but
not at doses of 50, 100 or 200 mg/kg. Both rats and mice exhibited patho-
logic changes of the stomach wall 1n all but the lowest dose level.
0849A 7-14 12/29/83
-------
7.2.2.1.2. Studies 90 Days or Longer 1n Duration — The subchronlc
toxldty of HEX 1s summarized In Table 7-5. Subchronlc toxldty studies 1n
B,C0F, mice and Fischer 344 rats have been conducted by SRI (1981b)
0 o I
under contract with the National Toxicology Program (NTP). In the mouse
study, dose levels of 19, 38, 75, 150 and 300 mg/kg HEX (94.3-97.4%) 1n corn
oil were administered by gavage to 10 mice of each sex, 5 days/week for 13
weeks (91 days). At the highest dose level (300 mg/kg), all male mice died
by day 8 and three females died by day 14. In female mice, the liver was
enlarged. Toxic nephrosls 1n females at doses of 75 mg/kg and higher was
characterized by lesions In the terminal portions of the convoluted tubules,
with basophllla 1n the Inner cortical zone and cytoplasmlc vacuollzatlon.
However, male mice at this level and higher did not show these effects.
Dose levels of 38 mg/kg HEX and above caused lesions 1n the forestomach,
Including ulceratlon 1n both males and females. The NOEL 1n mice for HEX
was 19 mg/kg and the LOEL was 38 mg/kg.
In the rat study, dose levels of 10, 19, 38, 75 and 150 mg/kg HEX 1n
corn oil were administered by gavage to groups of 10 male and female rats.
At the 38 mg/kg dose and higher levels, mortality and toxic nephrosls were
noted In both males and females. The male rats treated at the 19 mg/kg dose
level did not show any highly abnormal effects while female rats exhibited
lesions of the forestomach. Such lesions were observed 1n males at 38 mg/kg
or higher levels. There was a dose-related depression of body weight gain
relative to the controls. The NOEL 1n rats for HEX was 10 mg/kg and the
LOEL was 19 mg/kg.
A summary of the results of these two experiments appears 1n Table 7-6.
Based on these studies, a maximum tolerated dose (MTD) of 38 mg/kg for mice
and 19 mg/kg for rats was recommended for a chronic toxldty study.
0849A 7-15 12/29/83
-------
o
CD
lO
TABLE 7-5
Subchronlc Tox1c1ty of HEX
CVJ
UD
oo
CO
Study/Reference Species
90-Day Feeding Study/ Rat
SRI, 1981b
90-Day Feeding Study/ Mouse
SRI, 1981b
14-Week Inhalation Rat
Toxldty Study/
Dose
10, 19, 38, 75, 150 or
300 mg/kg {via gavage)
19, 38, 75, 150 or
300 mg/kg (via gavage)
0.01, 0.05 and 0.2 ppm
(5 days/week)
Results
NOEL
LOEL
NOEL
LOEL
NOEL
LOEL
- 10 mg/kg
- 19 mg/kg
- 19 mg/kg
- 38 mg/kg
-0.2 ppm
- NE
Effects at LOEL or
Lowest Dose
Lesions of forestomach 1n
female rats at 19 mg/kg
Lesions of forestomach 1n
both sexes at 38 mg/kg
No statistically signifi-
cant effects
Rand et al., 1982
14-Week Inhalation
Toxldty Study/
Alexander et al., 1980
Monkey 0.01, 0.05 and 0.2 ppm
(5 days/week)
NOEL - 0.2 ppm
LOEL - NE
No effects noted
NE - Not established
-------
o
CD
TABLE 7-6
Tox1colog1cal Parameters for Mice and Rats Administered HEX for 91 Days3
Pathology
Forestomach
Species/
Strain
Male mice/
B6C3F]
Female mice/
B6C3FT
Male rats/
Fischer 344
Dose
(mg/kg)
0
19
38
75
150
300
0
19
38
75
150
300
0
10
19
38
75
150
Mortality
1/10
0/10
0/10
0/10
0/10
10/10
0/10
0/10
0/10
0/10
0/10
3/10
3/10
1/10
1/10
1/10
3/10
7/10
Relative
Weight
Ga1nb
+36%
+ 9%
- 954
-45%
—
__
+13%
-13%
-13%
-25%
-38%
__
- 4%
- 8%
-20%
-49%
-57%
Inflammation
0/10
0/10
2/10
7/10
7/10
7/10
0/10
0/10
2/9
6/10
10/10
7/9
0/10
0/10
0/10
4/10
9/10
8/9
Hyperplasla
0/10
0/10
2/10
8/10
9/10
8/10
0/10
0/10
2/9
9/10
10/10
9/9
0/10
0/10
0/10
5/10
9/10
8/9
Kidney
Toxic
Nephrosls
0/10
0/10
0/10
0/10
0/10
0/10
0/10
0/10
0/9
10/10
10/10
7/10
0/10
0/10
0/10
10/10
9/10
8/10
PO
CO
CO
-------
00
TABLE 7-6 (cont.)
I
00
Pathology
Fores tomach
Species/
Strain
Female rats/
Fischer 344
Dose
(mg/kg)
0
10
19
38
75
150
Mortality
1/10
2/10
1/10
1/10
3/10
5/10
Relative
Weight
Ga1nb
OX
+ 4X
- 5%
- 2%
-SOX
-33X
Inflammation
0/10
0/10
2/10
2/10
9/10
9/10
Hyperplasla
0/10
0/10
2/10
5/10
9/10
9/10
Kidney
Toxic
Nephrosls
0/10
0/10
0/10
10/10
10/10
10/10
aSource: Southern Research Institute, 1981a,b
bRelat1ve weight gain 1s calculated as:
Dose Group Value - Control Group Value
Control Group Value
00
to
-------
7.2.2.2. SUBCHRONIC DERHAL TOXICITY —
7.2.2.2.1. Range-Finding Study -- Nalshsteln and Usovskaya (1965)
studied the effects of HEX applied to the skin of rabbits (strain unspeci-
fied) dally for 10 days. According to the authors, no effects were noted 1n
control and test animals given dally doses of 0.5-0.6 ml of a 20 ppm solu-
tion of HEX. No other data were available.
7.2.2.3. SUBCHRONIC INHALATION TOXICITY —
7.2.2.3.1. Range-Finding Studies — Rand et al. (1982) conducted a
range-finding study In which groups of 10 male and 10 female Sprague-Dawley
rats were exposed to 0.022, 0.11 or 0.5 ppm HEX 6 hours/day, 5 days/week for
a total of 10 exposures. Nine male rats and one female rat exposed to 0.5
ppm HEX were moribund after 5-7 exposures. These rats had dark red eyes,
labored breathing, and paleness of extremities. No mortalities were noted
1n the other exposure groups; however, the males 1n the 0.11 and 0.5 ppm
groups lost weight during the study and alterations 1n liver weight and
pathology were noted. The NOAEL for HEX exposure was 0.022 ppm and the LEL
was 0.11 ppm.
7.2.2.3.2. Studies 90 Days or Longer In Duration ~ Fourteen-week
Inhalation studies 1n rats and monkeys have been performed (Rand et al.,
1982; Alexander et al., 1980). Groups of 40 male and 40 female Sprague-
Dawley rats, weighing 160-224 g or groups of 12 Cynomolgus monkeys, weighing
1.5-2.5 kg, were exposed to HEX, 6 hours/day, 5 days/week, for as long as 14
weeks. Levels of exposure were 0, 0.01, 0.05 or 0.20 ppm HEX. In monkeys,
there were no mortalities, adverse clinical signs, weight gain changes,
pulmonary function changes, eye lesions, hematologlc changes, clinical
chemistry abnormalities or hlstopathologlc abnormalities at any dose level
tested. Thus, the NOEL for monkeys was 0.2 ppm HEX and the LOEL was not
determined.
0849A 7-19 12/29/83
-------
Male rats had a transient appearance of dark-red eyes at 0.05 and 0.2
ppm. At 12 weeks, there were marginal but not statistically significant
Increases In hemoglobin concentration and erythrocyte count 1n 0.01 ppm
males, 0.05 ppm females, and 0.20 ppm males and females. There were small
but not statistically significant changes 1n mean liver weight of all treat-
ment groups and similar changes In the kidneys of all treated males. There
were no treatment-related abnormalities 1n gross pathology or hlstopathol-
ogy. On this basis, the NOEL in rats was 0.2 ppm HEX; the LOEL was not
established.
7.2.2.4. SUMMARY -- The subchronlc toxldty of HEX has been studied
1n rats and mice following oral gavage and 1n rats and monkeys following
Inhalation exposure. In oral studies, rats and mice exhibited decreased
body weight gain, lesions of the forestomach, and toxic nephrosls. Female
mice also exhibited enlarged livers. The oral LOEL was 38 mg/kg for mice
and 19 mg/kg for rats. In the Inhalation studies, no abnormalities were
observed In monkeys at doses as high as 0.2 ppm HEX. No statistically
significant changes were noted In blood parameters, and In kidney and liver
weight 1n rats at all doses tested (range 0.01-0.2 ppm HEX). Thus, the NOEL
In both rats and monkeys was 0.2 ppm; no LOEL was established.
7.2.3. Chronic Toxldty.
7.2.3.1. CHRONIC ORAL TOXICITY — A chronic oral toxldty study of
HEX being conducted by SRI for the National Toxicology Program was termi-
nated In April 1982 because Inhalation was determined to be the more rele-
vant route of exposure. No other chronic oral toxldty data were available
for this report.
0849A 7-20 12/29/83
-------
7.2.3.2. CHRONIC DERMAL TOXICITY — Na1shste1n and Llsovskaya (1965)
conducted a skin painting study 1n rats at levels of 0, 0.0002, 0.0004 and
0.002 mg/kg/day. No adverse effects were noted In the 6-month study except
for neutropenla 1n the high-dose animals. Experimental details and quanti-
tative data were not reported. No other chronic dermal toxlclty data were
available for this report.
7.2.3.3. CHRONIC INHALATION TOXICITY — Treon et al. (1955) exposed
guinea pigs, rabbits, rats and mice to a concentration of 0.33 ppm HEX for 7
hours/day, 5 days/week for 25-30 exposures. Guinea pigs survived 30 expo-
sures; however, rats and mice did not survive 5 exposures and 4 of 6 rabbits
did not survive 25 exposures. Using a lower concentration (0.15 ppm HEX),
guinea pigs, rabbits and rats survived 150 seven-hour exposure periods (7
months). This level was too high for a chronic study In mice since 4/5
animals did not survive. The rats, guinea pigs and rabbits tolerated 0.15
ppm and did not exhibit any treatment-related effects. Thus, the NOEL for
rats, guinea pigs and rabbits and the LOEL for mice was 0.15 ppm HEX. The
NOEL for mice was not established while the LOEL for rats, guinea pigs and
rabbits was 0.33 ppm HEX.
A 30-week chronic Inhalation study of technical grade HEX 1n rats, 9654
pure with hexachloro-1,3-dlene and octachlorocyclopentene as Impurities, was
conducted by Shell Toxicology Laboratory (Clark, 1982). Four groups of 8
male and 8 female Wlstar albino rats were exposed to HEX at nominal concen-
trations of 0, 0.05, 0.1 and 0.5 ppm for 6 hours/day, 5 days/week, for 30
weeks and were observed for a 14-week recovery period without HEX exposure.
At the highest dose level 4 males and 2 females died. In males, there was a
depressed body weight gain 1n the 0.5 ppm group relative to controls begin-
ning at 7 weeks of exposure and persisting throughout the remainder of the
0849A 7-21 01/05/84
-------
study. Females In the high and medium dose groups had lower body weights at
the end of the recovery period as compared to the controls. At 0.5 ppm,
there were pulmonary degenerative changes noted In both sexes although the
males were affected more severely. At the highest dose, there were mild
degenerative changes In the liver and kidneys at 30 weeks In a few rats and
kidney weights were significantly Increased 1n the females. After 30 weeks
of study, there was no biologically significant toxlclty noted 1n animals
exposed to concentrations of 0.05 or 0.1 ppm (Clark, 1982). Thus, the NOEL
In rats exposed to vapors of HEX was 0.05 ppm; the LOEL was 0.1 ppm based on
body weight, organ weight, and hlstopathology data.
A chronic Inhalation study of HEX has been scheduled by the National
Toxicology Program (Abdo, 1983).
7.2.3.4. SUMMARY — The chronic effects of HEX have been studied
primarily via Inhalation exposure. No oral studies and one under-reported
dermal study were located for this review. The Inhalation toxlclty of HEX
has been evaluated 1n rats, mice, rabbits and guinea pigs. Four of five
mice did not survive exposure to 0.15 ppm HEX, while the other species did
not show effects following 150 seven-hour exposures to 0.15 ppm. In a more
recent study, chronic degenerative changes 1n the lung, liver and kidneys
were noted In rats exposed to 0.5 ppm HEX and the NOEL for rats was 0.05 ppm
HEX. A 2-year Inhalation bloassay has been scheduled by the National
Toxicology Program and results are due 1n 1984 (Abdo, 1983).
7.3. MUTAGENICITY
7.3.1. MutagenlcHy. Goggelman et al. (1978) found that HEX was not
mutagenlc before or after liver mlcrosomal activation at 2.7xlO~3 M 1n an
E. coll K,0 back mutation system. In this test there was 705i survival of
_ | ^
bacteria at 72 hours. HEX was not tested at higher concentrations because
0849A 7-22 12/30/83
-------
U was cytotoxlc to £. coll. A previous report from the same laboratory
{Grelm et al., 1977) Indicated that HEX was also not mutagenlc In S. typhl-
murlum strains TA1535 (base-pair mutant) or TA1538 (frame shift mutant)
after liver mlcrosomal activation; however, no details of the concentrations
tested wore given. Although tetrachlorocyclopentadlene Is mutagenlc 1n
these systems, probably through metabolic conversion to the dlenone, It
appears that the chlorine atoms at the C-l position of HEX hindered meta-
bolic oxidation to the corresponding acylatlng dlenone (Grelm et al., 1977).
A study conducted by Industrial B1o-Test Laboratories (IBT, 1977) also
suggests that HEX Is not mutagenlc 1n S. typhlmurlum. Both HEX and Us
vapors were tested with and without metabolic activation. The vapor test
was done In desiccators with only the TA-100 strain of S. typhlmurlum. It
1s not clear from the presented data of the test with the vapors that suffi-
cient amounts of HEX or adequate times of exposure were used. Exposure
times of 30, 60 or 120 minutes were studied. Longer exposures In the
presence of the HEX vapors may be necessary for observation of a potential
mutagenlc effect. The statement 1n the text that testing was conducted 1n
the toxic range 1s not convincingly supported by the results shown 1n
lable 9 of the IBT study.
At concentrations of up to 1.25xlO~3 jig/ml 1n the presence of an S-9
liver activating system, HEX was not mutagenlc In the mouse lymphoma muta-
tion assay. MutagenlcHy could not be evaluated at higher concentrations
because of the cytotoxldty of HEX (LHton B1onet1cs, Inc., 1978a). This
assay uses L5178Y cells that are heterozygous for thymldlne klnase (TK+/-)
and are bromodeoxyurldlne (BUdR) sensitive. The mutation Is scored by
cloning with BUdR 1n the absence of thymldlne. HEX Is highly toxic to these
0849A 7-23 01/19/84
-------
cells, particularly 1n the absence of activating system (at 4xlO~5
pl/mfc) and a positive control, d1methyln1trosam1ne, was mutagenlc at
0.5 yl/ois..
Williams (1978) found that HEX (10~6 M) was Inactive 1n the Hver
epithelial culture hypoxanthlne-guanlne-phosphorIbosyl transferase (HGPRT)
locus/mutation assay. At 1(TS M 1t also failed to stimulate ONA repair
synthesis 1n hepatocyte primary cultures. Negative results were also
obtained 1n an additional unscheduled ONA synthesis assay (Brat, 1983).
Two recent studies provided by NTP (Juodelka, 1983) also failed to
demonstrate the mutagenldty of HEX. In S. typh1mur1um strains TA98, TA100,
TA1535 and TA1537, levels of up to 3.3 yg/plate were not mutagenlc without
activation and levels of up to 100.0 yg/plate were not mutagenlc after
mlcrosomal activation. Higher levels could not be tested because of exces-
sive killing of the bacteria. In the Drosophlla sex-linked recessive lethal
test, HEX was not mutagenlc. The doses used 1n this study were 40 ppm by
feeding for 3 days or a single Injection of 2000 ppm.
HEX has also been assayed 1n the mouse dominant lethal test (Litton
B1onet1cs, Inc., 1978b). In this assay, 0.1, 0.3 or 1.0 mg/kg HEX was
administered by gavage to 10 male CD-I mice for 5 days and these mice were
then mated throughout spermatogenesls (7 weeks). This test determines
whether the compound Induces lethal genetic damage to the germ cells of
males. There was no evidence of dominant lethal activity at any dose level
by any parameter; e.g., fertility Index, Implantations/pregnancy, average
resorptlons/pregnancy. In this study, the highest dose used was the LD^,
determined by a 5-day mortality study 1n male CD-I mice.
0849A 7-24 01/19/84
-------
7.3.2. Summary. The weight of the available evidence suggests that HEX
1s not a mutagen. Negative mutagenldty results were obtained 1n bacteria,
liver epithelial cells, DrosophHa. mouse lymphoma cells and In the mouse
dominant lethal test. Furthermore, HEX did not Induce unscheduled DNA
synthesis In rat hepatocytes. However, a potential problem occurs In the
Interpretation of the in vitro studies. The protocols of these studies,
except for the desiccator study conducted by Industrial B1o-Test Labora-
tories (1977) and perhaps, the mouse lymphoma study completed by LHton
B1onet1cs, Inc. (1977), Indicate that no precautions were taken to control
the volatility and escape of HEX from the test system. Modifications of
standard in vitro protocols are often necessary for volatile test chemicals.
In addition, because HEX appears to be very toxic, the dose range for
detecting a positive genetic effect may be very narrow.
7.4. CARCINOGENICITY
7.4.1. In Vivo CardnogenlcHy. Bloassays of HEX for possible cardno-
genldty have not been conducted. However, NTP has scheduled HEX for car-
c1nogen1c1ty testing by the Inhalation route In rats and mice (Abdo, 1983).
7.4.2. In Vitro CardnogenlcHy. The ability of HEX to Induce morpho-
logic transformation of BALB/3T3 cells in vitro has been studied by Litton
B1onet1cs, Inc. (1977). The procedure employed by the Investigators was
similar to that of Kakunaga (1973). Evaluation of the carcinogenic activity
was based on the following criteria:
The endpolnt of carcinogenic activity 1s determined by the presence
of f1broblast1c-l1ke colonies which are altered morphologically 1n
comparison to the cells observed 1n normal cultures. These (trans-
formed) cells grow 1n criss-cross, randomly oriented fashion with
overlapping at the periphery of the colony. The colony exhibits
dense piling up of cells. On staining the foci are deeply stained
and the cells are basophlUc 1n character and variable 1n size.
These changes are not observed 1n normal cultures, which stain
uniformly.
0849A 7-25 01/19/84
-------
Assays were performed at levels of 0.0, 0.01, 0.02, 0.039, 0.078 and
0.156 vH/ml. The cultures were exposed for 48 hours followed by an
Incubation pei iod of 3-4 weeks. The cultures were observed dally. The
selection of test doses was based on previous cytotoxldty tests using a
wide range of HEX concentrations. The doses selected allowed an 80-100%
survival of cells as compared to solvent negative controls. This high sur-
vival rate permitted an evaluation of In vitro malignant transformation 1n
cultures treated with HEX as compared with the solvent controls. 3-Methyl-
cholanthrene at a dose level of 3 yg/ml was used as a positive control.
Results Indicated that HEX was not responsible for any significant carcino-
genic activity.
7.4.3. Summary. HEX has not been demonstated to be a carcinogen j_n vitro
In transformation assays using BALB/3T3 cells. In vivo bloassays have not
been conducted; however, an Inhalation bloassay has been scheduled by the
National Toxicology Program.
7.5. TERATOGENIC AND REPRODUCTIVE EFFECTS
7.5.1. Teratogen1c1ty. The teratogenlc potential of HEX was evaluated 1n
pregnant Charles River CD rats that were administered HEX (98.25%) 1n corn
oil, by gastlc Intubation, at dose levels of 3, 10 and 30 mg/kg/day from
days 6 through 15 of gestation. A control group received the vehicle (corn
oil) at a dose volume of 10 mil/kg/day. Survival was 100%, and there was
no difference 1n mean maternal body weight gain between dosed groups and
controls. There were no differences 1n the mean number of Implantations,
corpora lutea, live fetuses, mean fetal body weights or male/female sex
ratios among any of the groups, and there were no statistical differences 1n
malformation or developmental variations compared with the controls when
external, soft tissue and skeletal examinations were performed (IRDC, 1978).
0849A 7-26 01/19/84
-------
Murray et al. (1980) evaluated the teratogenlc potential of HEX (98%) 1n
CF-1 mice and New Zealand white rabbits. Mice were dosed at 0, 5, 25 or 75
mg/kg/day HEX by gavage from days 6-15 of gestation while rabbits received
the same dose from days 6-18 of gestation. The fertility of both the
treated mice and rabbits was not significantly different from the control
groups. In the mice, no evidence of maternal toxldty, embryotoxlclty or
teratogenlc effects was observed. A total of 249-374 fetuses (22-33 lit-
ters) were examined 1n each dose group.
In rabbits, maternal toxldty was noted at 75 mg/kg/day (diarrhea,
weight loss and mortality), but there was no evidence of maternal toxldty
at the lower levels. There were no embryotoxlc effects at any dose level.
Although there was an Increase 1n the proportion of fetuses with 13 ribs at
75 mg/kg/day over controls, this was considered a minor skeletal variation,
and the authors concluded that HEX was not teratogenlc at the levels tested.
Studies on the teratogenlc potential of Inhaled HEX were not located 1n
the review of the scientific literature.
7.5.2. Reproductive Effects. No data were located that addressed the
reproductive effects of HEX.
7.5.3. Summary. HEX has been tested for teratogenlc potential by oral
gavage 1n rats, mice and rabbits. No material toxldty or teratogenlc
effects were noted 1n rats or mice when HEX was administered on days 6
through 15 of gestation at doses of up to 25 and 75 mg/kg/day, respectively.
Rabbits exhibited maternal toxldty when HEX was administered at 75
mg/kg/day from days 6 through 18 of gestation and an Increase In fetuses
with 13 ribs was also noted at this dose level. The latter was considered
to be a minor skeletal variation by the authors. No maternal toxldty on
fetal abnormalities were noted 1n rabbits at lower doses. HEX therefore
0849A 7-27 01/19/84
-------
does not appear to be teratogenlc by oral gavage 1n the species and at the
doses tested. HEX was not tested for teratogenlclty following Inhalation
exposures.
7.6. HUMAN EXPOSURE AND HEALTH EFFECTS
7.6.1. Human Exposure. According to a recent NIOSH estimate, 1427 work-
ers are occupatlonally exposed to HEX (NIOSH, 1980). Velslcol officials
estimate that approximately 157 employees are potentially exposed to HEX 1n
their production facilities. A summary of monitoring results 1s presented
1n Tables 7-7 and 7-8 for the Velslcol Memphis and Marshall plants, respec-
tively. In addition, acute human exposure has been reported In homes near
waste sites where HEX has been disposed (Clark, 1982; Ella, 1983).
7.6.2. Health Effects. Very little detailed Information 1s available
concerning the effects of HEX exposure on humans. The odor threshold 1s
approximately 0.15 ppm, however, there has been great Individual variation.
According to the Material Safety Data Sheet prepared by Hooker (Hooker
Chemical Corp., 1979) and based on animal studies, HEX vapors are very Irri-
tating to all mucous membranes, causing tearing, sneezing and salivation;
skin contact can cause blisters and burns; Inhalation of vapors or mists can
result In the secretion of excess fluid 1n the lungs; and Inhalation or
1ngest1on may cause nausea, vomiting, diarrhea, lethargy, respiratory
Impairment and Injury to the liver or kidneys.
In reviewing the health effects concerning HEX, one must review the
potential for human exposure associated with chemical waste sites. In the
cases of the Michigan and Tennessee studies, the waste sites have contami-
nated adjacent areas, groundwater, and a nearby lake. While HEX 1s nonper-
slstent, some HEX contaminating compounds, such as hexachlorobenzene and
octachlorocyclopentene (OCCP), are quite stable.
0849A 7-28 01/19/84
-------
o
00
TABLE 7-7
Memphis HEX Monitoring Summary
(Velslcol Chemical Corporation, April 6, 1982)*
-J
1
ro
10
PO
v»
oo
0
Unit
HEX
HEX
HEX
HEX
HEX
HEX
HEX
HEX
Formulations
Materials
Handling
Endrln
Endrln
C.A.
C.A.
C.A.
Description
Process Operator
No. 1 Operator
No. 2 Process Operator
No. 2 Cycle Operator
No. 2 Chlorine Operator
Environmental Operator
a) HEX Bottoms Drumming
Area Sample Control Room
Brinks Filter Cleaning
(maintenance personnel)
HEX Drummers
HEX Railroad Tank
Car Unloading
R2 Filter Operator
Rl Operator
No. 1 Operator
No. 2 Operator D34
No. 2 Operator R6
No. of
Samples
2
5
5
5
6
6
1
12
2
4
1
1
1
2
2
2
Average
Duration
(minutes)
445
432
418
417
415
436
50
476
387
407
279
281
334
437
440
437
Range of Sample
Concentrations
(ppm)
0.009 -
0.006 -
0.006 -
0.001 -
0.004 -
0.004 -
0.016
0.002 -
0.004 -
0.002 -
0.013
0.003
0.002
0.0077
0.0107
0.0065
0.011
0.033
0.029
0.048
0.016
0.161
0.018
0.006
2.0337
- 0.0102
- 0.0198
- 0.0169
Average
TWA (ppm)
0.009
0.015
0.014
0.017
0.008
0.035
--
0.009
0.005
0.010
0.008
--
--
0.008
0.014
0.011
co
-------
TABLE 7-7 (cont.)
o
00
10
Unit
C.A.
C.A.
Heptachlor
Heptachlor
Heptachlor
Heptachlor
Heptachlor
Description
Packaging Operator
Area Sample - control room
No. 1 Operator
No. 2 Operator Catalyst
237 Operator
Utility Operator
Cleaning Sparkler Filter
a) Celling Sample
No. of
Samples
1
3
2
2
2
1
3
1
Average
Duration
(minutes)
396
475
407
415
392
363
44
15
Range of Sample
Concentrations
(ppm)
0.035
0.0003
0.007
0.006
0.006
0.006
0.002
0.006
- 0.0014
- 0.009
- 0.009
- 0.019
- 0.005
Average
TWA (ppm)
0.031
0.001
0.007
0.007
0.011
0.005
0.0003
--
*Source: Levin 1982a
ppm = parts of HEX per million parts of air by volume
TWA = 8-hour time-weighted average. The TWA calculation was made assuming that the only chemical exposure
was during the sampling period.
C.A. = chlorendic anhydride.
NOTE: The employee monitoring (indicated job function) results are reported without regard to respirator
use. In operators where HEX exposure is possible, respirators are required and are worn.
CO
O
00
-------
TABLE 7-8
2 Marshall HEX Monitoring Summary
:> (Velslcol Chemical Corporation, April 6, 1982)*
Unit Description
Chlordane No. 1 Operator
Chlordane No. 2 Operator
Chlordane No. 3 Operator
Chlordane Area sample - North
Control Room
is Chlordane HEX Filter Changing
Chlordane Waste Handling HEX
Mud Drumming
Chlordane a) Celling Sample
b) Loading HEX Waste
Truck - Celling Sample
c) Sump Pit Dumping -
Celling Sample
No. of
Samples
8
8
8
13
1
6
2
2
2
Average
Duration
(minutes)
451
455
451
433
15
307
15
15
15
Range of Sample
Concentrations
(ppm)
0.0091 - 0.0316
0.0080 - 0.0195
0.0002 - 0.0325
0.002 - 0.0254
0.1322
0.0006 - 0.0606
0.0005 - 0.0061
0.1199 - 0.2325
0.0333 - 0.1129
Average
TWA (ppm)
0.017
0.013
0.014
0.016
--
0.020
--
—
—
S
*Source: Levin 1982a
ppm = parts of HEX per million parts of air by volume
TWA = 8-hour time-weighted average. The TWA calculation was made assuming that the only chemical exposure
was during the sampling period.
NOTE: The employee monitoring (Indicated job function) results are reported without regard to respirator
use. In operators where HEX exposure 1s possible, respirators are required and are worn.
-------
7.6.2.1. EFFECTS FOLLOWING INCIDENTS OF ACUTE EXPOSURE — Treon et
al. (1955) reported that members of a group conducting toxldty tests devel-
oped headaches when they were accidentally exposed to unknown concentrations
of HEX, which had escaped Into the room when an aerated exposure chamber was
opened.
A well-documented Incident of acute human exposure to HEX occurred In
March 1977 at the Morris Forman Wastewater Treatment Plant In Louisville.
Kentucky. The Incident has been described and reviewed In several papers
(Komlnsky et al., 1980; Wilson et al., 1978; Morse et al.. 1979). The
complete details of the original NIOSH Hazard Evaluation and Technical
Assistance Report Number TA-77-39 (Komlnsky et al., 1978), are available
from the National Technical Information Service (NTIS).
In 1977, the Louisville treatment facility was contaminated with ~6 tons
of HEX and OCCP, a waste byproduct of HEX manufacture (Morse et al., 1979).
The contamination was traced to one large sewer line that passed through
several populated areas. Concentrations of HEX detected In the sewage water
at the plant ranged as high as 1000 ppm, and levels 1n the sewer line ranged
up to 100 ppm. A1r samples from the sewer line showed HEX concentrations as
high as 400 ppb. Although airborne concentrations of HEX at the time of the
exposure were unknown, airborne concentrations In the primary treatment
areas (screen and grit chambers) ranged between 270 and 970 ppb 4 days after
the plant had closed. (The TWA for HEX was 10 ppb 1n 1977.) During the
cleanup of the contamination, workers using steam attempted to remove an
odoriferous and sticky substance from the bar screens and grit collection
system. This produced a blue haze which permeated the primary treatment
area. Airborne HEX concentration of the blue haze generated by the cleanup
procedures was reported to be 19.2 ppm (Komlnsky et al., 1980).
0849A 7-32 01/19/84
-------
Both the Center for Disease Control (CDC) and NIOSH sent representatives
to the plant, with each group developing questionnaires seeking Information
on the type and duration of symptoms (Morse, et al., 1979; Komlnsky, et al.,
1980). A total of 193 employees were Identified as those potentially
exposed for 2 or more days during the 2 weeks before the plant was closed
(Morse et al., 1979). A questionnaire was sent to each of these workers and
145 (75%) responded. Workers with complaints of mucous membrane Irritation
were given a physical examination, and blood and urine samples were col-
lected for clinical screening by an Independent laboratory. Data were also
collected on the exposure levels and symptoms 1n several Individual cases of
acute exposure to the chemical vapors.
Results of the CDC and NIOSH questionnaires showed that the odor of HEX
was detected before the onset of symptoms by 94% of the workers. The most
common symptoms reported were eye Irritation (59%), headaches (45%) and
throat Irritation (27%) (Table 7-9). Of the 41 workers physically examined,
6 had physical signs of eye Irritation (I.e., tearing or redness) and 5 had
signs of skin Irritation. Laboratory analyses of blood and urine specimens
from these workers showed elevations of lactic dehydrogenase (LDH) 1n 27%
and protelnurla 1n 15%. However, no clinical abnormalities were reported by
the plant physician, the local hospital, or by the Independent laboratory 3
weeks later (Morse et al., 1978, 1979).
While there was difficulty 1n measuring the amount of exposure by the
plant workers, over half of the cleanup crew was monitored. Laboratory
tests showed no significant abnormalities, however, several minimal-to-mild
abnormalities did appear 1n liver function tests. These abnormalities are
listed 1n Table 7-10. In addition, more detailed correlation of acute expo-
sure level data to symptomatology was reported for 9 adults (Komlnsky et
0849A 7-33 01/19/84
-------
TABLE 7-9
Symptoms of 145 Wastewater Treatment Plant Employees
Exposed to HEX (Louisville, KY, March 1977)*
Symptom
Eye Irritation
Headache
Throat Irritation
Nausea
Skin Irritation
Cough
Chest pain
Difficult breathing
Nervousness
Abdominal cramps
Decreased appetite
Decreased memory
Increased saliva
No. of Employees
with Symptom
86
65
39
31
29
28
28
23
21
17
13
6
6
Percent of Employees
with Symptom
59
45
27
21
20
19
19
16
14
12
9
4
4
*Source: Morse et a!., 1978
0849A
7-34
01/19/84
-------
TABLE 7-10
Abnormalities for 18 of 97 Cleanup Workers
at the Morris Forman Treatment Plant
Abnormal Results
Serum
Laboratory Test Normal Range
Glutamate-
Oxalacetate Transamlnase 7-40 mU/mj.
Serum
Serum
Serum
Alkallne Phosphatase 30-100 mU/mj,
Total BHIrubln 0.15-10 mg/X
Lacrate Dehydrogenase 100-225 mU/ml
Range
40-49
50-59
60-69
70-79
80-89
90-99
100-109
110-119
120-129
1.0-1.9
230-239
No.'
5
1
4
0
1
1
3
1
1
1»
1
aFor Individuals with more than one serial blood test, only the most
abnormal result 1s tabulated.
Associated with serum glutamate-oxalacetate transamlnase of 66
U = Units of enzyme activity
0849A 7-35 01/19/84
-------
al., 1980). These data are reviewed In Table 7-11. The exposure levels
could not be estimated accurately because of prior exposure or the worker
had used protective equipment.
A questionnaire was also given to a selected sample of residents of a
48-block area surrounding the contaminated sewer line. A total of 212 occu-
pants were surveyed. Very few residents noted an unusual odor (3.8%). The
most prevalent symptoms were stomachaches (5.2%), burning or watering eyes
(4.7%) and headaches (4.7%). There was no association between symptom rates
and the distance of households from the contaminated sewer line. The
authors stated that no significant ambient air concentrations of HEX were
found 1n these areas (Komlnsky et al., 1978). The same types and frequency
of symptoms reported by workers to be associated with HEX exposure were
reported by residents 1n the survey which led the authors to suggest that
these symptoms were unrelated to HEX exposure (Morse et al., 1978).
Several papers have documented another similar Incident 1n Hardeman
County, Tennessee (Clark, 1982; Meyer, 1983; Ella, 1983). While conducting
a ser1oep1dem1ologic study of the health risks from bacteria and viruses
associated with the treatment of municipal wastewater, potential human expo-
sure to organic chemicals emitted from the wastewater being treated at one
of the plants 1n the study was recognized (Ella, 1983). In 1978, workers at
the treatment plant began complaining of acute symptoms similar to those
found In the Louisville plant. A1r and wastewater monitoring was started,
analysis of urine specimens, analysis of blood and liver function tests, and
an Illness symptom questionnaire were used to collect data. Two groups from
other treatment facilities were used for comparison. Three separate urine
screen surveys were conducted. There were 36 Individuals In the November
1978 exposed group, and this group was expanded to 49 In January 1979, with
0849A 7-36 01/19/84
-------
o
CO
TABLE 7-11
Overview of Individual Exposure - Symptomatology Correlations at the -Morris Forman Treatment Plant3
Case
No.
Estimated Airborne Exposure
Immediate Symptoms
Persistence of Symptoms
Laboratory Abnormalities
i
CO
19,200 ppb HCCPO and 650 ppb
OCCP for several seconds (No
protective equipment)
2,3,4 7083 ppb HCCPO and 446 ppb
OCCP for several seconds.
(Half-face respirator)
5,6 40-52 ppb HCCPD and 9-21 ppb
OCCP (Half-face respirator)
7,8 Exact exposure unknown
(Half-face respirator)
980 ppb HCCPD for 15
minutes; OCCP not measured
(No protective equipment)
Lac Miration; skin 1rrHat1on on face
neck; dyspnea and chest discomfort;
nausea (several minutes later)
LacMmatlon; Irritation of exposed
skin
Slight eye Irritation
Slight skin Irritation
Irritated eyes
Nasal Irritation and sinus congestion
after 2 weeks of Intermittent exposures
1.5 hrs. post-exposure: fatigue;
erythema of exposed skin; eye
Irritation subsided 1n 1 day; chest
discomfort persisted several days.
Asymptomatic at 2 hours, except
for soreness around eyes
No residual after cessation of
Faces felt "puffy" and "wlndburned"
for 1-2 days after exposure. This
was noted also by friends and
family. No residual skin lesions.
Eyes felt "dry and Irritated" for
2-3 days after exposure. Nasal
Irritation ceased within 1-2 days
of cessation of exposure.
Lab work 4 days post expo-
sure was normal0
Lab work 7 days post expo-
sure was normal on one
worker0
Normal 7 days later on one
None available
None available
aSource: Komlnsky, et al., 1980
DLaboratory work was same as done on cleanup crew
CO
o
oo
co
-------
31 repeating Individuals. Utilizing an unexposed group (those not exposed
to the treatment facility or the contaminated water), a comparison of vari-
ous liver enzymes was done (Table 7-12). Although there were Increases 1n
some liver enzymes, and Indications of a subcllnlcal transitory liver In-
sult, there were no significant differences among the groups tested (Ella,
1983; Meyer, 1983). The situation at the Memphis treatment facility Is the
only known existing case of essentially continuous low-level chronic expo-
sures with Intermittent higher acute exposures, especially during an acci-
dental discharge from the nearby pesticide manufacturing facility (Ella,
1983). A continuous study of the workers at this plant, as well as the
extent of such exposure at other wastewater treatment plants receiving
Industrial chemical wastes, 1s warranted.
7.6.2.2. EPIDEMIOLOGIC STUDIES — Mortality studies have been con-
ducted on the workers Involved 1n the production of HEX or formulation of
HEX products. The Shlndell report (1980) was a cohort study of workers
employed at the Velslcol Chemical Corporation plant at Marshall, Illinois
between 1946 and 1979. The purpose was to evaluate the vital status of all
former and current employees (>3 months) who were present during the
manufacture of chlordane. In preparing the cohort, the authors noted the
difficulties 1n tracing some of the employees. In the final cohort of 783
Individuals, 97.4% of the employees were located and their vital status
Included 1n the study. The analysis showed no significant differences 1n
mortality rates between these employees and the U.S. population. The
observed deaths for all causes, Including heart disease and cancer, were
fewer than the calculated expected deaths among members of the U.S. popula-
tion (Shlndell, 1980).
0849A 7-38 01/19/84
-------
TABLE 7-12
00
Hepatic Profile Comparison of Hardeman County: Exposed Group (November 1978) and Control Group0
PO
\
co
o
CO
Results
Parameter''
November 1978 Control
Exposed Group Group
Significance of
Difference (t test)
Alkaline phosphatase (32-72 mll/ma
age 21, 25-150 mU/ml age 21)
Serum gamma glutamlc transamlnase
(SGGT) (5-29 mU/ma)
Albumin (3.5-5.0 g/dl)
Total b1!1rub1n (0.1-1.1 mg/di)
Serum glutamlc pyruvlc transamlnase
(SGOT) (8-22 mU/ml)
Meanc
Range
No. above normal/
total tested
Meanc
Range
No. above normal/
total tested
Meanc
Range
No. above normal/
total tested
Meanc
Range
No. above normal/
total tested
Meanc
Range
No. above normal/
total tested
88.1
34-360
17/36
9.47
2-54
3/36
4.35
3.9-4.8
0.36
0.240
0.1-0.8
0/31
19.5
12-36
11/36
61.5
31-220
8/56
11.56
4-56
3/56
4.93
4.2-6.2
0/57
0.51
0.2-1.7
4/52
16.08
9-140
7/56
0.016
0.430
0.0001
0.0001
0.001
aSource: Meyer, 1983
Normal range indicated in parentheses
""Geometric mean
U = Units of enzyme activity
-------
Wang and MacMahon (1979) conducted a study on a group of 1403 males
employed at the Marshall and Memphis plants for >3 months. There were 113
observed deaths compared to 157 expected, yielding a standardized mortality
ratio (SMR) of 72, not remarkable for an employed population. The two
highest SMRs were 134 for lung cancer and 183 for cerebrovascular disease,
but only the latter was statistically significant (p<0.05). The authors
suggested that these effects were unrelated to exposure because the deaths
showed no consistent pattern with duration of employment or with duration of
follow-up.
Shlndell and Associates (1981) completed an epldemlologlcal study for
Velsicol. The study group consisted of over 1000 employees (93% of the
cohort) of the Memphis, Tennessee plant for the years 1952-1979, coinciding
with the manufacture of heptachlor. Again, the researchers found no signif-
icant difference in mortality between the control. and exposure groups and
fewer deaths in the study group. The investigators report that there was no
excess mortality by job function.
Buncher et al. (1980) studied the mortality of workers at a chemical
plant which produced HEX. The Investigators reviewed personnel who worked
for at least 90 days between October 1, 1953 and December 31, 1974. There
were 341 workers (287 male and 54 female) who fit the criteria. Health
status was ascertained through 1978 and expected numbers of deaths were
calculated based upon the U.S. population and specific for sex, age and
calendar year. The SMR was 69 which showed the workers to be healthier than
the general population. Deaths due to specific cancers, all cancers, dis-
ease of the circulatory and digestive systems were fewer than the expected
numbers. The authors noted that the time since Initial exposure, at the
most 25 years, reduced the power of the study to detect cancers which may
have a 10-40 year latent period.
0849A 7-40 01/19/84
-------
7.6.3. Summary. While there 1s the limited human experience with respect
to mortality, there Is only limited Information on the morbidity results 1n
those exposed to HEX. Acute Inhalation produces a high prevalence of head-
aches and severe Irritation of the eyes, nose, throat and lungs. Dermal
contact can cause severe burns. Ep1dem1olog1c studies have generally shown
no significant differences 1n mortality between workers exposed to HEX 1n
the workplace and the general population. Although, a significant excess of
deaths from cerebrovascular disease was reported 1n one study, the deaths
showed no consistent pattern with duration of employment or follow-up.
Current human exposure 1s limited to Improper handling and disposal and
proximity to either manufacturing sites utilizing HEX or disposal sites. No
other chronic human health effects data from HEX exposure have been located
1n the literature.
0849A 7-41 01/19/84
-------
8. OVERVIEW
8.1. EFFECTS OF MAJOR CONCERN
Although minimal quantitative Information 1s available on the effects of
HEX on humans, transient exposure to HEX vapor has been found to cause Irri-
tation to the eyes, nose and throat, as well as headaches. The levels of
exposure causing these effects are not well defined but they are at a level
close to the odor threshold, which varies Individually and may be as low as
0.15 ppm. There Is no Information on the long-term effects of a single
exposure or of subchronlc exposure. There Is no Information available on
the carclnogenlclty of HEX. In vitro mutagenlclty or transformation tests
were negative. The \n vivo mouse dominant lethal assay was negative at the
levels tested. HEX has not been shown to be teratogenlc 1n three species.
Therefore, the major concern 1s the acute toxic effects on the respira-
tory system when HEX 1s Inhaled. Although the chronic toxldty data are
presently limited, the systemic toxic effects of the Inhalation of HEX have
been demonstrated after acute and subchronlc exposure, suggesting that
chronic Inhalation exposure to low doses of HEX may have potential adverse
effects.
8.1.1. Principal Effects and Target Organs. Repeated exposure of several
animal species to levels of HEX vapor 1n the 0.1-0.2 ppm range has been
found to cause pulmonary degenerative changes (Treon et al., 1955; Rand et
al., 1982, Clark et al., 1982). Treon et al. (1955) reported mild degener-
ative changes 1n the kidneys, liver, brain, heart and adrenal glands. Rand
et al. (1982), however, did not confirm this and suggested that the changes
found by Treon et al. (1955) were caused by Impurities 1n the preparation of
HEX. Acute exposure via oral and dermal routes also cause effects on the
respiratory system (Kommlnenl, 1978; Southern Research Institute, 1980a).
1816A 8-1 01/03/84
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Death from acute exposure by any tested route appears to be associated with
respiratory failure (Lawrence and Dorough, 1981).
There are Insufficient data to Identify clearly the site most sensitive
to prolonged, repeated exposure to HEX. However, researchers found 1n com-
paring routes of admlnlstraton that regardless which route was used, damage
to the lungs occurred (Lawrence and Dorough, 1982). When HEX 1s adminis-
tered orally to animals, the kidneys may be the most sensitive site, since
subchronlc dosing of rats and mice was found to cause nephrosls especially
In females (Southern Research Institute, 1981a,b). Although the oral route
may not be significant In human exposure, the fact that the kidneys are a
possible target organ In subchronlc exposure Indicates that low-level,
prolonged systemic exposure from any ambient route may affect the kidneys.
Ihe liver has also been an affected organ as seen 1n the low-level exposures
of the Tennessee exposed population.
8.1.2. Animal Toxldty Studies Most Useful for Hazard Assessments. The
studies most useful for prediction of hazards are those which use a variety
of dose levels, a variety of species, adequate sample sizes, and display the
full range of effect severity, from no effects through mortality. The major
quantitative goal Is to estimate the threshold level for adverse effects.
I.e., the level at or above which adverse effects are observed. In this
regard, the most appropriate studies are those presenting no-observed-effect
levels (NOEL), no-observed-adverse-effect levels (NOAEL) and adverse-effect
levels (AEL), I.e., those dose rates which bracket the threshold level
(Tables 8-1 and 8-2). Because dosing regimes varied among studies, a time-
weighted average (TWA) dally exposure level has been calculated to use as a
comparison. Dose rates labeled "EL" (for "effect level") are associated
with effects which may or may not be adverse.
1816A 8-2 01/19/84
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TABLE 8-1
Oral Toxlclty Data for Threshold Estimates
Exposure
Animal Duration
(days)
Rat
Rat
House
Rat
House
Rat
10
12
12
91
91
216
aT1me -weighted-average
bDef1nH1ons:
NOEL -
NOAEL -
EL
AEL -
Exposure Effect
Levela Severity''
10 mg/kg
30 mg/kg
100 mg/kg
25 mg/kg
50 mg/kg
50 mg/kg
100 mg/kg
7 mg/kg
14 mg/kg
27 mg/kg
14 mg/kg
27 mg/kg
54 mg/kg
0.2 mg/kg
2.0 mg/kg
dally exposure levels
NOEL
EL
AEL
NOAEL
AEL
EL
AEL
EL
EL
AEL
NOAEL
EL
AEL
NOEL
EL
Reference
IRDC, 1978
IRDC, 1978
IRDC, 1978
SRI, 1980b
SRI, 1980b
SRI, 1980a
SRI, 1980a
SRI, 1981a
SRI, 1981a
SRI, 1981a
SRI, 1981b
SRI, 1981b
SRI, 1981b
Nalshsteln and
Llsovskaya, 1965
No-observed-effect level
No-observed-adverse-effect level
Effects level
Adverse effects level
1816A
8-3
12/29/83
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TABLE 8-2
Inhalation Tox1c1ty Data for Threshold Estimates
Animal
Rat
Exposure
Duration
(days)
14
Exposure
Level3
0.004 ppm
0.020 ppm
0.089 ppm
Effect
Sever Hyb
NOAEL
EL
AEL
Reference
Rand et al., 1982
Rand et al., 1982
Rand et al., 1982
Rat, 42
guinea pig
Rat 90
Monkey 90
Rat 210
Rat, rabbit, 216
guinea pig
0.069 ppm
0.002 ppm
0.009 ppm
0.036 ppm
0.002 ppm
0.009 ppm
0.036 ppm
0.009
0.018
0.089
0.031 ppm
AEL
NOAEL
EL
EL
NOAEL
NOAEL
NOAEL
NOEL
EL
AEL
AEL
Treon et al., 1955
Rand et al., 1982
Rand et al., 1982
Rand et al., 1982
Rand et al., 1982
Rand et al., 1982
Rand et al., 1982
Clark et al.,
Clark et al.,
Clark et al.,
Treon et al.,
1982
1982
1982
1955
aT1me-we1ghted-average dally exposure levels
bDef1n1t1ons: NOEL - No-observed-effect level
NOAEL - No-observed-adverse-effect level
EL - Effects level
AEL - Adverse effects level
1816A
8-4
12/29/83
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Toxlclty from Inhalation of HEX appears to be more severe than that of
oral or dermal exposure and may be the cause of so few studies showing minor
effects. Rand et al. (1982) used sufficiently low concentrations 1n a
14-day study on rats and 1n a 90-day study on rats and monkeys to elicit
effect levels. Clark and researchers (Clark et al., 1982) found that rat
groups (18 males and 18 females per group) exposed to HEX at 0.05 ppm (0.009
ppm dally TWA) for 30 weeks showed no effects. However, Rand et al. (1982)
found their animals had elicited some effects at the same level (0.009 ppm
dally TWA) In only 90 days. Treon et al. (1955) exposed their animals for
216 days and found adverse effects at 0.03 ppm dally TWA.
Short-term oral studies by IRDC (1978) and SRI (1980a,b) provide
Information on toxlclty to rats and mice, although the study sizes were
small (5 and 10 animals per dose group, respectively). The 90-day study by
SRI (1981a,b) on rats and mice 1s the only short-term oral study providing
no-effect levels, and the Na1shste1n and Llsovskaya (1965) 6-month study on
rats Is the only long-term data set giving no-effect levels. These three
studies had marginally adequate sample sizes.
The remaining studies detailed 1n Chapter 7, and those listed 1n the
toxldty table 1n Appendix 1, provide Information on more severe effects
which can be used to show consistency with the threshold estimates. By
themselves, however, they cannot be used to estimate a threshold since none
adequately describes the shape of the dose-response severity relationship.
For example, dose rates associated with NOFELs (no-observed-frank-effect-
levels) Indicate that no significant change 1n frank effects was attributed
to the exposure. Milder effects were not Investigated, so that the NOFEL
could dramatically overestimate the threshold.
1816A 8-5 01/19/84
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8.2. FACTORS INFLUENCING HEALTH HAZARD ASSESSMENT
8.2.1. Exposure. Data are available regarding the potential human expo-
sure to HEX. It appears that any significant exposure would be the result
of Improper disposal or accidental spill. Limited data were presented for
the air and water levels of HEX In these Incidences. Emissions data, from
which atmospheric exposure estimates could be derived, have been sent to the
U.S. EPA by Velslcol but are considered confidential business Information
(CBI) and are not available In this report. No HEX residue was detected 1n
fish taken from the waters near the Velslcol plant In Memphis In 1982. No
Information was available regarding HEX contamination of other foods.
Although occupational exposure 1s expected to be minimal, the long-term
health effects to continuous low-level exposure and/or Intermittent acute
exposure in man are not known. Waste handlers and sewage treatment workers
have been shown to be occupations at risk.
8.2.2. Lowest Observed Effect Level. Both single dose and short-term
range-finding Inhalation studies (7 hours/day) by Rand et al. (1982) demon-
strated "a steep dose response effect of HEX exposure with a threshold of
toxlclty In rats between 0.11 and 0.5 ppm." This observation Is based on
severe Irritation of the lungs, consequent Inflammation, and Impaired
respiratory function 1n rats. The 1WA dally exposure levels, from the NOAEL
to the AEL, give a threshold level of 0.004-0.089 ppm. Subchronlc exposure
(-90 days) to rats and monkeys (Rand et al., 1982) Indicate a threshold of
0.002-0.036 ppm based on TWA dally dose rates. Clark et al. (1982) exposed
rats for 30 weeks and found an AEL 1n the 0.089 ppm TWA range with no
adverse effects at 0.009 ppm TWA. However, Treon et al. (1955) exposed
rabbits, rats and guinea pigs to a TWA level of 0.031 ppm for 216 days and
1816A 8-6 12/29/83
-------
caused moderate adverse effects, so the lifetime experimental threshold 1s
likely to be somewhat less. No lifetime data exist for determining NOELs or
NOAELs.
As expected, the toxldty from Inhalation seems highly dependent on the
dose rate. In several studies, a dose change of less than one order of
magnitude separated minor effects from Increased mortality. This pattern
was observed for acute studies through chronic studies. In the previous
comparison of threshold levels, the difference between the EL and NOAEL
depends to a large degree on the researchers' determination and discussion
of the effects shown by HEX. With the narrow range between these dose
levels, the determination of exact separations between effect levels and
adverse effect levels 1s limited by the data.
The short-term oral studies (IRDC, 1978; SRI, 1980a,b) Indicate a lowest
effect level for dally exposure to be 25-100 mg HEX/kg bw, based on rat and
mouse data. Subchronlc oral studies (SRI, 1981a,b) suggest a lowest effect
level of 7-54 mg/kg/day based on TWA dose rates used with rats and mice.
Ihe rats responded at lower doses than did the mice, but the metabolic
similarities to man are not sufficiently well understood to allow choice of
a best animal model. Chronic oral exposure to 0.2-2.0 mg/kg showed no
adverse effects (Na1shste1n and Llsovskaya, 1965).
8.2.3. Carc1nogen1c1ty. There are no animal bloassay data Indicating
that HEX 1s carcinogenic to animals. An Inhalation cardnogenesls bloassay
1n mice and rats 1s to be done by NTP (Abdo, 1983). No unit risk estimate
for HEX has been suggested because carcinogenic bloassay data for HEX have
not been completed.
1816A 8-7 01/19/84
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8.3. REGULATIONS AND STANDARDS
Hexachlorocyclopentadlene has been addressed under numerous U.S.
statutes. These have been grouped according to the type of activity or
medium being controlled.
8.3.1. Occupational Standards. There 1s no current OSHA standard for HEX
levels 1n the workplace (29 CFR 1910). However, the AC6IH has adopted a
threshold limit value (TLV), expressed as an 8-hour time-weighted average
(TWA), of 0.1 mg/m3 (0.01 ppm). A short-term exposure limit (STEL), the
maximal concentration allowable 1n a 15-mlnute period, of 0.3 mg/m3 (0.03
ppm) for HEX has also been adopted (ACGIH, 1982). The levels are based on
Treon et al. (1955).
In 1978, NIOSH classified HEX as a Group II pesticide and recommended
criteria for standards for occupations 1n pesticide manufacturing and formu-
lating. These standards rely on engineering controls, work practices and
medical surveillance programs, rather than workplace air limits, to protect
workers from the adverse effects of pesticide exposure 1n manufacturing and
formulating. NIOSH specifically chose not to establish scientifically valid
environmental (workplace air) limits for pesticides (except those already
promulgated), because exposure via other routes, especially dermal, had
proven to be of critical Importance for many pesticides and because NIOSH
believed that "Immediate action" was needed to protect workers 1n pesticide
manufacturing and formulating plants (NIOSH, 1978).
8.3.2. Transportation Regulations. The Hazardous Materials Transporta-
tion Act specifies the requirements to be observed 1n the preparation for
shipment and transport of hazardous materials (49 CFR 171-179). The trans-
port of HEX by air, land and water 1s regulated by these statutes, and the
Department of Transportation has designated HEX as a "hazardous material"
1816A 8-8 12/28/83
-------
(ID Number UN 2646), a "corrosive material", and a "hazardous substance" (49
CFR 172.101). The maximum net quantity of HEX permitted 1n one package for
transport by passenger-carrying aircraft or rallcar has been set at 1 quart,
while the maximum net quantity for cargo aircraft has been set at 10 gallons
per package. Transport on deck or below deck by cargo vessel 1s also per-
mitted (49 CFR 172.101).
The Hazardous Materials Transportation Act, 1n conjunction with the
Comprehensive Environmental Response, Compensation and Liability Act
(CERCLA), also provides that common carriers of hazardous substances may be
held liable for releases of hazardous substances In amounts equal to or
greater than their designated reportable quantity (RQ). The RQ for HEX has
been set at 1 pound (0.454 kg) (49 CFR 172).
8.3.3. Solid Waste Regulations. Under the Resources Conservation and
Recovery Act (RCRA), EPA has designated HEX as a hazardous toxic waste.,
Hazardous Waste No. U 130 (40 CFR 261.33), subject to disposal and permit
regulations of Title 40, Code of Federal Regulations, Parts 262-265 and
Parts 122-124. Hexachlorocyclopentadlene 1s a hazardous constituent of:
wastewater treatment sludge from the production of chlordane, wastowater and
scrub water from the chlorlnatlon of cyclopentadlene 1n the production of
chlordane, and filter solids from the filtration of HEX In the production of
chlordane (Hazardous Waste Nos. K032, K033 and K034, respectively) 1s also
designated as a hazardous waste (40 CFR 261.320) and subject to RCRA
disposal regulations.
8.3.4. Food Tolerances. Under FIFRA, a tolerance of 0.3 ppm has been
established for chlordane residues, which are not to contain more than IX of
HEX (40 CFR 180.122).
1816A 8-9 12/29/83
-------
8.3.5. Water Regulations. Under section 311 of the Federal Water Pollu-
tion Control Act, EPA designated HEX as a hazardous substance (40 CFR 116.4)
and established an RQ of 1 pound (0.454 kg) for HEX (40 CFR 117.3). Dis-
charges equal to or greater than the RQ Into or upon U.S. waters are prohi-
bited unless the discharge 1s 1n compliance with applicable permit programs
(40 CFR 117.11).
Under the Clean Water Act, EPA has designated HEX as a toxic pollutant;
I.e.. priority pollutant (40 CFR 401.15). Effluent limitations guidelines,
new source performance standards, and pretreatment standards have been
developed or will be developed for the priority pollutants for 21 major
Industries. Specific definitions for classes and categories are set forth
1n 40 CFR Parts 402 through 699.
Under the Clean Water Act, Ambient Water Quality Criteria (AWQC) for HEX
have also been developed (U.S. EPA, 1980c). Based on available toxlclty
data, for the protection of public health the level derived was 206
vg/a. Using organoleptlc data, for controlling undesirable taste and
odor quality of ambient water the estimated level was 1 vg/B.. AWQC for
freshwater aquatic life from acute and chronic toxldty Indicated concentra-
tions as low as 7.0 and 5.2 vg/fc, respectively. Acute toxlclty to salt-
water aquatic life was Indicated at concentrations as low as 7.0 yg/a.
(U.S. EPA, 1980c).
8.3.6. A1r Regulations. Hexachlorocyclopentadlene 1s currently not
regulated under the Clean A1r Act.
8.3.7. Other Regulations. Pursuant to rules under sections 8(a) and 8(d)
of the Toxic Substances Control Act (44 FR 70666), all manufacturers and
processors of HEX are required to report production, use and exposure Infor-
mation, as well as health and safety Information on HEX to EPA's Office of
1816A 8-10 12/28/83
-------
loxlc Substances. The deadline for submission of Preliminary Assessment
Information Manufacturer's Report on HEX (40 CFR 712) was November 19, 1982.
In 1979, the Interagency Testing Committee recommended that HEX be
considered for health and environmental effects testing under Section 4(a)
of the TSCA (44 FR 70666). This recommendation was based on evidence of
potential human exposure and a potential for environmental persistence and
bloaccumulatlon. In 1982, the EPA responded (U.S. EPA, 1982) 1n the Federal
Register. The following 1s the statement from that notice:
EPA has decided not to Initiate rulemaklng to require testing of
HEX under section 4 of TSCA because EPA does not believe that there
Is a sufficient basis to find that current manufacture, distribu-
tion 1n commerce, processing, use or disposal of HEX may present an
unreasonable risk of Injury to the environment or of mutagenlc and
teratogenlc health effects. Neither has the EPA found evidence
that there Is substantial or significant environmental release of
HEX. In addition, certain new studies have become available since
the ITC's report or are underway, making additional testing for
chronic and oncogenlc effects unnecessary.
1816A 8-11 01/19/84
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L • ' . k'' ''
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1817A 9-20 12/22/83
-------
APPENDIX
A-1
-------
TABLE A-l
Toxldty Table for Hexachlorocyclopentadlene
Species
Rabbit
Rat
Rat
Rat
Rat
Rat
Rat
Rat
Route
gavage
gavage
gavage
gavage
gavage
oral
oral
gavage
Number of Body
Animals Weight
6
10
10
NH
10
25
25
10 0.107
Exposure
Level
420 mg/kg
280 mg/kg
280 mg/kg
0 mg/kg
50 mg/kg
530 mg/kg
650 mg/kg
75 mg/kg
Duration
of
Exposure
1 day
1 day
1 day
1 day
1 day
1 day
1 day
1 day
Exposure
Schedule
1 exposure
1 exposure
1 exposure
1 exposure
1 exposure
1 exposure
1 exposure
1 exposure
Organ
NH
NH
NH
GI.LG
GI.LG
NH
NH
GR.OT
Severity
FEL
PEL
FEL
control
AEL
PEL
FEL
NOFEL
Comments
Peanut oil vehicle; exposure
level 420-620 mg/kg, LDso
Also toxic to heart, brain,
kidney and liver
Ha.le; peanut oil vehicle; minimum
lethal dose 280 mg/kg
Female; peanut oil vehicle; mini-
mum lethal dose 280 mg/kg
Females; all animals sacrificed
24 hours post-exposure
Exposure level range; 50-300 mg/kg
Female albinos; corn oil vehicle;
LD50
Hale albinos; corn oil vehicle;
LD50
Fischer 344 strain; both sexes,
Reference
Treon et al. ,
1955
Treon et al. ,
1955
Treon et al. ,
1955
Komm1nen1. 1978
Komm1nen1, 1978
IROC. 1972
IRDC. 1972
SRI, 1980a
Rat gavage
Rat gavage
Rat gavage
Rat gavage
10
0.107 150 mg/kg 1 day
1 exposure GR.OT NOFEL
10 0.107 300 mg/kg 1 day
10 0.107 600 mg/kg 1 day
10 0.107 1200 mg/kg 1 day
1 exposure GR.OT PEL
1 exposure GR.OT PEL
1 exposure GR.OT PEL
body weight range = (males:
101-133 g; females: 89-105 g);
vehicle-corn oil
Fischer 344 strain; both sexes, SRI, 1980a
body weight range = (males:
101-133 g; females: 89-105 g);
vehicle-corn oil; animals 1n
75-150 mg/kg dose levels
basically asymptomatic
20X mortality; both females, on SRI, 1980a
days 10 and 13, all effects
more severe 1n females
100X mortality; males by day 10 SRI, 1980a
and females by day 6
100X mortality by day 2 SRI, 1980a
-------
TABLE A-l (cont.)
i
10
Number of Body Exposure
Species Route Animals Weight Level
Duration Exposure
of Schedule
Exposure
Organ
Severity Comments
Reference
House gavage
House gavage
House gavage
House gavage
House gavage
Rat gavage
House gavage
House gavage
House gavage
10 0.021 75 mg/kg
10
10
10
1 day
10 0.021 150 mg/kg 1 day
10 0.021 300 mg/kg 1 day
10 0.021 600 mg/kg 1 day
10 0.021 1200 mg/kg 1 day
5 0.165 926 mg/kg 1 day
0 mg/kg 5 days
0.1 mg/kg 5 days
0.3 mg/kg 5 days
1 exposure GR.OT
1 exposure GR.OT
1 exposure GR.OT
1 exposure GR.OT
1 exposure GR.OT
1 exposure NH
RP
RP
RP
NOFEL B6C3F1 strain; both sexes; body
weight range - (males: 20-24 g;
females: 19-22 g); vehicle-corn
oil; discoloration of urine noted
NOFEL B6C3F1 strain; both sexes; body
weight range « (males: 20-24 g;
females: 19-22 g); vehicle-corn
oil; discoloration of urine noted;
also noted ruffled fur but no
change In activity
NOFEL B6C3F1 strain; both sexes; body
weight range = (males: 20-24 g;
females: 19-22 g); vehicle-corn
oil; discoloration of urine noted;
also noted ruffled fur but no
change 1n activity; animals con-
sidered normal by day 6
FEL 20X mortality-! male and 1 female;
effects same as 1200 mg/kg level
but reversible by day 9 or 12
FEL 100X mortality by day 8; effects
Included decreased activity.
ruffled fur and red urine
FEL Charles River CD strain; LDsg;
vehicle-corn oil. Observed for
14 days post-exposure
control CD-I strain; males; DHSO adminis-
tered as solvent vehicle
NOFEL Each male mated on da^ 7 to un-
exposed females. No evidence for
significant dominant lethal activity
NOFEL Each male mated on day 7 to un-
exposed females. No evidence for
significant dominant lethal activity;
all values within control levels
SRI, 1980a
SRI, 1980a
SRI. 1980a
SRI, 1980a
SRI, 1980a
IROC. 1968
LUton Blonetlcs
Inc., 1978b
LUton Blonetlcs
Inc., 1978b
LUton Blonetlcs
Inc.. 1978b
-------
TABLE A-l (cont.)
Species
Mouse
Rat
Rat
Rat
J_ Rat
Rat
Rat
Mouse
Mouse
Mouse
Mouse
Rat
Route
gavage
oral
oral
oral
oral
oral
oral
gavage
gavage
gavage
gavage
gavage
Number of Body
Animals Weight
10
5
5
5
5
5
5
NM
NM
NM
NM
10 0.124
Exposure
Level
1 mg/kg
0 mg/kg
3 mg/kg
10 mg/kg
30 mg/kg
100 mg/kg
300 mg/kg
0 mg/kg
5 mg/kg
25 mg/kg
75 mg/kg
0 mg/kg
Duration
of
Exposure
5 days
10 days
10 days
10 days
10 day;
10 days
10 days
10 days
10 days
10 days
10 days
12 days
Exposure
Schedule Organ Severity Comments
RP NOFEL Each male mated on day 7 to un-
exposed females. No evidence for
significant dominant lethal activity;
all values within control levels
RP control Charles River (CD); 12-week-old
females; vehicle: corn oil;
schedule: days 6-15 of gestation
RP NOEL No teratogenlc effects or. change
1n maternal appearance or
behavior
RP NOEL No teratogenlc effects or change
1n maternal appearance or
behavior
RP EL No teratogenlc effects, decreased
maternal body weight gain
RP.GR AEL No teratogenlc effects. Maternal
body weight loss; reduced gain
RP FEL 100X mortality by gestation day 10
RP control CF-1; cottonseed oil vehicle;
exposure schedule: days 6-15 of
gestation
RP NOEL No teratogenlc, embryotoxlc or
fetotoxlc effects
RP NOEL No teratogenlc, embryotoxlc or
fetotoxlc effects; similar
results 1n rabbit
RP NOEL No teratogenlc, embryotoxlc or
fetotoxlc effects; similar
results 1n rabbit
GR.GI control Fischer 344 strain, both sexes;
Reference
LUton B1onet1cs
Inc., 1978b
IRDC, 1978
IRDC, 1978
IRDC, 1978
IRDC, 1978
IRDC, 1978
IROC, 1978
Murray et al. ,
1980
Murray et al. ,
1980
Murray et al. ,
1980
Murray et al. ,
1980
SRI, 19BOb
body weight range = (males:
129-165 g; females: 74-128 g);
vehicle-corn oil
-------
TABLE A-l (cont.)
Species Route
Number of Body Exposure
Animals Weight Level
Duration
of
Exposure
Exposure
Schedule
Organ Severity
Comments
Reference
i
v/i
Rat gavage
Rat gavage
Rat gavage
Rat gavage
Rat gavage
House gavage
House gavage
House gavage
House gavage
House gavage
10 0.124 25 mg/kg
12 days
10 0.124 50 mg/kg 12 days
10 0.124 100 mg/kg 12 days
10 0.124 200 mg/kg 12 days
10 0.124 400 mg/kg 12 days
10 0.024 0 mg/kg 12 days
10 0.024 50 mg/kg 12 days
10 0.024 100 mg/kg 12 days
10 0.024 200 mg/kg 12 days
10 0.024 400 mg/kg 12 days
GR.6I NOAEL
GR.GI AEL
GR.GI AEL
GR.GI PEL
GR.GI FEL
NS.GI control
NS.GI EL
NS.GI AEL
NS.GI AEL
NS.GI FEL
No deaths or significant gross or SRI, 1980b
clinical effects; average weight
gain slightly depressed 1n
females; males were unaffected
No deaths or significant clinical SRI. 1980b
effects; depression of average
weight gain 1n both sexes; gross
changes 1n stomach wall
No deaths; depression of average SRI, 1980b
weight gain 1n both sexes; gross
and clinical effects
Lethal to 1 (1/5) males, 4 (4/5) SRI, 1980b
females; severe gross and clinical
effects
Lethal to all males (5/5) and 4 SRI, 1980b
(4/5) females; severe gross and
clinical effects
B6C3F1 strain; both sexes; body SRI, 1980b
weight range = (males: 23-31 g;
females: 19-22 g); vehicle-corn oil
No chemical related deaths; slight SRI, 1980b
Inactivity and stomach changes
noted 1n both sexes (1/5 males and
1/5 females)
No deaths 1n either sex; Inactivity SRI. 1980b
and stomach changes 1n all males
(5/5) and 4 (4/5) females
Lethal to 1 (1/5) males; all an1- SRI, 1980b
mals showed signs of clinical
toxldty
Lethal to 4 (4/5) males and all SRI, 1980b
(5/5) females prior to day 7.
Clinical and gross toxldty
observed
-------
TABLE A-l (cent.)
Species Route
Number of Body
Animals Weight
Exposure
Level
Duration
of
Exposure
Exposure
Schedule
Organ Severity
Comments
Reference
Mouse gavage
Rat gavage
Rat gavage
Mouse gavage
Mouse gavage
Mouse gavage
Mouse gavage
10
20
3>
I
CT>
Rat
Rat
Rat
Rat
gavage
gavage
gavage
gavage
20
20
20
20
20
20
20
20
20
0.024 800 mg/kg 12 days
0.134 0 mg/kg 13 weeks 5 days/week KO.GI control
0.134 10 mg/kg 13 weeks
0.134 19 mg/kg 13 weeks
0.134 38 mg/kg 13 weeks
0.134 75 mg/kg 13 weeks
5 days/week KD.GI EL
S days/week KD.GI EL
5 days/week KD.GI AEL
5 days/week KD.GI FEL
0.134 150 mg/kg 13 weeks 5 days/week KO, 61 FEL
0.022 0 mg/kg 13 weeks 5 days/week KD.GI control
0.022 19 mg/kg 13 weeks
0.022 38 mg/kg 13 weeks
0.022 75 mg/kg 13 weeks
NS.GI FEL Lethal to all animals (10/10) prior SRI, 1980b
to day 5; clinical toxldty but no
gross observations
Fischer 344 strain; both sexes; SRI, 1981a
vehicle: corn oil; body weight
range = (males: 130-170 g;
females: 99-135 g)
White'raised area on stomach In SRI, 1981a
1 (1/10) males
Epithelial hyperplasla noted 1n SRI, 1981a
2 (2/10) females only. Appear-
ance of other lesions also ob-
served In vehicle controls and not
necessarily chemically Induced.
Increased severity of effects SRI, 1981a
Increased severity of effects; SRI, 1981a
lethal to 1 (1/10) males and
1 (1/10) females
Lethal to 6 (6/10) males; SRI, 1981 a
depression of average weight
gain 1n both sexes
B6C3F1 strain; both sexes; vehicle: SRI, 1981b
corn oil; body weight range =
(males: 24-28 g; females: 17-20 g)
KD.GI NOAEL No significant pathological or SRI, 1981b
clinical effects. Increased
I1ver-to-body weight ratio.
KD.GI EL M1ld epithelial hyperplasla and SRI, 1981b
focal Inflammation 1n 2 (2/10)
males and 2 (2/9) females
KO.GI AEL Minimal toxic nephrosls 1n fe- SRI, 1981b
males; hyperplasla and Inflamma-
tion of forestomach 1n both sexes
-------
TABLE A-l (cont.)
Species
House
House
Rat
Rat
> Rat
1
Rat
Rat
Guinea
pig
Guinea
pig
Guinea
pig
Rat
Rat
Route
gavage
gavage
oral
oral
oral
oral
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Number of Body
Animals Weight
20 0.022
20 0.022
10
30 0.110
30 0.110
30 0.110
4
2
2
2
4
4
Exposure
Level
150 mg/kg
300 mg/kg
20 mg/kg
0.02 ug/kg
0.2 ug/kg
2 ug/kg
46.5 ppm
7.2 ppm
13.5 ppm
20 ppm
3.1 ppm
7.2 ppm
Duration Exposure
of Schedule Organ
Exposure
13 weeks 5 days/week KD.GI
13 weeks 5 days/week KD.GI
6 months NH
6 months BL.GR
6 months BL.GR
6 months BL.GR
30 minutes LG.NS
1 hour LG
1 hour LG
1 hour LG
1 hour LG
1 hour LG
Severity Comments
AEL Increased severity of effects;
depression 1n average weight
gain 1n both sexes
FEL Lethal to all males and 3 (3/10)
females. Toxic nephrosls noted
1n females only
FEL White rats; unspecified oral
route; 20X mortality
NOEL Aqueous solution; unspecified oral
route; total animal number = 90
Body weight range = 100-120 g
NOEL Aqueous solution; unspecified oral
route; total animal number - 90
Body weight range = 100-120 g
EL Aqueous solution; unspecified oral
route; total animal number = 90
Body weight range = 100-120 g
AEL Exposure duration: 30-60 minutes,
similar effects - rabbit, mouse,
guinea pig; also toxic to growth,
other organs
NOFEL Lethal to OX of animals
FEL SOX mortality
FEL 100% mortality
NOFEL OX mortality
FEL SOX mortality
Reference
SRI, 1981b
SRI, 1981b
Na1shste1n and
Llsovskaya, 1965
Na1shste1n and
Llsovskaya, 1965
Na1shste1n and
Llsovskaya, 1965
Na1shste1n and
Llsovskaya, 1965
Treon et al. ,
1955
Treon et al. ,
1955
Treon et al. ,
1955
Treon et al. ,
1955
Treon et al. ,
1955
Treon et al. ,
1955
-------
TABLE A-l (cont.)
Species
Mouse
Mouse
Mouse
Rabbi t
Rabbit
^ Rabbit
i
co
Rat
Guinea
pig
Guinea
pig
Guinea
pig
Rat
Rat
Rat
Mouse
Mouse
Number of Body Exposure
Route Animals Weight Level
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
inhalation
Inhalation
Inhalation
Inhalation
Inhalation
5
5
5
3
3
3
4
2
2
2
4
4
4
5
5
1 .4 ppm
7.2 ppm
13.8 ppm
1 . 4 ppm
3.1 ppm
7.2 ppm
20 ppm
3.1 ppm
7 . 1 ppm
12.4 ppm
1 .4 ppm
3.1 ppm
7.1 ppm
1 . 4 ppm
3.1 ppm
Duration Exposure
of Schedule Organ
Exposure
1
1
1
1
1
1
1,
3,
3.
3
3
3
3
3
3
hour
hour
hour
hour
hour
hour
,25 hour
.5 hour
.5 hour
.5 hour
.5 hour
.5 hour
.5 hour
.5 hour
.5 hour
LG
LG
LG
LG
LG
LG
LG
LG
LG
LG
LG
LG
LG
LG
LG
Severity
NOFEL
PEL
PEL
NOPEL
PEL
PEL
PEL
NOPEL
PEL
PEL
NOFEL
PEL
PEL
PEL
PEL
Comments •
OX mortality
20X mortality
100X mortality
OX mortality
67X mortality
100X mortality
100X mortality
Lethal to OX of animals
50X mortality
100X mortality
OX mortality
SOX mortality
100X mortality
20X mortality
SOX mortality
Reference
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
et
et
et
et
et
et
et
et
et
et
et
et
et
et
et
al..
al..
al..
al.,
al.,
al.,
al..
al..
al..
al.,
al..
al.,
al..
al..
al..
-------
TABLE A-l (cont.)
VD
Species
House
Rabbit
Rabbit
Rat
Rat
Rat
Rat
Guinea
pig
Guinea
pig
Guinea
pig
Rat
Rat
Rat
House
House
Number of Body Exposure
Route Animals Weight Level
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
5
3
3
10
10
10
10
2
2
2
4
4
4
5
5
7.1
6.4
7.1
176
17.
0.250 1.6
0.250 3.5
1.5
3.2
6.7
1.5
3.2
6.7
1.5
3.2
ppm
ppm
ppm
.2 ppm
624 ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
3
3
3
4
4
4
4
7
7
7
7
7
7
7
7
Duration Exposure
of Schedule Organ
Exposure
.5 hour
.5 hour
.5 hour
hours
hours
hours
hours
hours
hours
hours
hours
hours
hours
hours
hours
LG
LG
LG
LG.SK
LG.SK
LS.GR
LG.GR
LG
LG
LG
LG
LG
LG
LG
LG
Severity
FEL
FEL
FEL
FEL
FEL
FEL
FEL
NOFEL
FEL
FEL
FEL
FEL
FEL
FEL
FEL
Comments
100% mortality
67% mortality
100% mortality
100% mortality within 48 hours;
also toxic/other organs
100% mortality within the 48-hour
exposure period
Sprague-Dawley strain; males
(200-300 g) LC50
Sprague-Dawley strain; females
(200-300 g) LC50
Lethal to 0% of animals
50% mortality
100% mortality
25% mortality
75% mortality
100% mortality
80% mortality
100% mortality
Reference
Treon
1955
Treon
1955
Treon
1955
IRDC,
IRDC.
et al..
et al.,
et al..
1972
1972
Rand et al.,
1982
Rand et al.,
1982
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
Treon
1955
et al..
et al..
et al.,
et al.,
et al.,
et al.,
et al..
et al..
-------
TABLE A-l (cont.)
Species
Rabbit
Rat
Rat
Rat
Rat
Rabbit
Guinea
pig
Rat
Rat
Rat
Rat
Monkey
Monkey
Number of Body Exposure Duration
Route Animals Weight Level of
Exposure
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
3 7.5 ppm 7 hours
20 0.162 0 ppm 14 days
20 0.162 0.022 ppm 14 days
20 0.162 0.11 ppm 14 days •
20 0.162 0.5 ppm 14 days
6 0.34 ppm 35 days
2 0.34 ppm 42 days
80 0.192 0 ppm 90 days
80 0.192 0.01 ppm 90 days
80 0.192 0.05 ppm 90 days
80 0.192 0.2 ppm 90 days
12 2.000 0 ppm 90 days
12 2.000 0.01 ppm 90 days
Exposure
Schedule Organ
LG
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days /week
5 days/week GR
7 hours/day GR
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
6 hours/day LG.BL
5 days/week
Severity Comments
FEL 100X mortality
control Range finding study, Sprague-Dawley
strain; both sexes (136-188 g)
NOAEL No significant clinical or patho-
logical effects
EL Decreased body weight with In-
creased liver weight; males more
affected than females
AEL Pathological and blood chemistry
changes. Also toxic to liver,
kidney, nasal passage. Dose-
related effects
FEL Lethal to 4 (4/6) animals
AEL Guinea pigs survived 30 periods
of exposure; lethal to mice and
rats similarly exposed before
20th exposure period
control Sprague-Dawley strain; both sexes
(160-224 g)
NOAEL No measurable clinical or physical
effects
EL Marginal hematologlc and organ
weight changes
EL Marginal hematologlc and organ
weight changes
control Cynomolgus monkeys; both sexes
(1.5-2.5 kg)
NOAEL No treatment-related abnormali-
ties - organ weights, pathology
Reference
Treon et al.,
1955
Rand et al. ,
1982
Rand et al.,
1982
Rand et al. ,
1982
Rand et al.,
1982
Treon et al. ,
1955
Treon et al. ,
1955
Rand et al.,
1982
Rand et al.,
1982
Rand et al..
1982
Rand et al. ,
1982
Rand et al. ,
1982
Rand et al. ,
1982
or hlstopathology
-------
TABLE A-l (cent.)
Species
Monkey
Monkey
Guinea
pig
> Rat
i
—
Rat
Rat
Human
Rabbi t
Guinea
pig
Guinea
pig
Guinea
pig
Guinea
pig
Route
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
dermal
dermal
dermal
dermal
dermal
Number of Body
Animals Height
12 2.000
12 2.000
2
4
4
4
145
6
1
1
1
1
Exposure Duration
Level of
Exposure
0.05 ppm 90 days
0.2 ppm 90 days
0.15 ppm 216 days .
12.4 ppm NH
1 ppm NH
0.15 ppm NH
0.4 mg/J, NH
430 mg/kg 1 day
0 mg/kg 1 day
300 mg/kg 1 day
600 mg/kg 1 day
1200 mg/kg 1 day
Exposure
Schedule
6 hours/day
5 days/week
6 hours/day
5 days/week
7 hours/day
5 days /week
1 exposure
1 exposure
1 exposure
1 exposure
1 exposure
Organ
LG.BL
LG.BL
GR.LV,
KD
LG.NS
LG.NS
LG.NS
NS.HT
NH
LG.SK
LG.SK
LG.SK
LG.SK
Severity Comments
NOAEL No treatment-related abnormali-
ties - organ weights, pathology
or Mstopathology
NOAEL No treatment-related abnormali-
ties - organ weights, pathology
or hlstopathology
AEL Concentration tolerated by guinea
pigs, rabbits and rats; lethal to
4 (4/5) nrice similarly exposed.
HI Id degenerative changes noted
1n LV and KD
AEL Exposure level: 12.4-13.8 ppm,
similar effects 1n rabbit, mouse,
guinea pig
AEL Exposure level: 1-1.6 ppm; symptoms
developed over a period of hours
EL Exposure level: 0.15-0.33 ppm;
Irritation seen only 1n mouse
AEL Ep1dem1olog1cal study; exposure to
mixture of HEX and octachlorocyclo-
pentene. Exposure level: 100-1000
ppm In wastewater
FEL Painted; lethal dosage range:
430-630 mg/kg
control Painted; animals sacrificed 24
hours post-exposure
AEL Painted; animals sacrificed 24
hours post-exposure
AEL Painted; animals sacrificed 24
hours post-exposure
FEL Expired prior to sacrifice
Reference
Rand et al.,
1982
Rand et al. ,
1982
Treon et al.,
1955
Treon et al. ,
1955
Treon et al. ,
1955
Treon et al.,
1955
Slngal, 1978
Treon et al. ,
1955
Komn1nen1. 1978
Komm1nen1, 1978
Komm1nen1, 1978
Komm1nen1, 1978
-------
TABLE A-l (cont.)
c
ta
1 Species Route
m
1 Rabbit dermal
i
I Rabbit dermal
i
2 Rabbit dermal
o
cc
S Monkey dermal
•f Rabbit dermal
Monkey dermal
Number of Body Exposure Duration
Animals Weight Level of
Exposure
4 200 mg/kg 1 day
4 2000 mg/kg 1 day
3 250 mg/kg 1 day
1 NM 3 days
NR NM 10 days
1 NM NM
Exposure
Schedule Organ Severity Comments
1 exposure GR.SK FEL Painted; New Zealand white, both
sexes; lethal/both males
1 exposure GR.SK FEL Painted; New Zealand white, both
sexes; lethal/both males; mortal-
ity within 24 hours
1 exposure SK AEL Dose-related effects persisting
for many days
SK AEL Exposure level = 0.05 ml of 10X
ultrasene solution. Increased
solution concentration (20, 40,
60, 90X) produced more severe
effects
SK NOEL Exposure level = 0.5-0.6 ml of 20
ppm HEX 1n aqueous solution
SK NOEL Exposure' level * 0.01 ml of
0.001-10X ultrasene solution;
similar effect 1n guinea pig
Reference
IRDC, 1972
IRDC, 1972
Treon et al.
1955
Treon et al.
1955
•
Nalshsteln and
Llsovskaya, 1965
Treon et al.
1955
f
NM = Not mentioned
BL = Blood; GI = gastrointestinal; GR = growth/weight gain; KD = kidney; LG = lung; MT = metabolism; NS = nervous system Including CNS; OT = other; RP ='
reproductive; SK = skin
NOEL = No observed effect level. That exposure level at which there are no statistically significant Increases 1n frequency or severity of effects between
the exposed population and the appropriate control.
NOAEL = No observed adverse effect level. That exposure level at which there are no statistically significant Increases In frequency or severity of adverse
effects between the exposed population and the appropriate control. Effects are produced at this level, but they are not considered to be adverse.
EL = Effect level. The exposure level 1n a study or group of studies which produces statistically significant Increases 1n frequency or Intensity of
effects between the exposed population and Us appropriate control. It has not been decided whether these effects are adverse.
AEL = Adverse effect level. The exposure level 1n a study or group of studies which produces statistically significant Increases 1n frequency or severity
of adverse effects between the exposed population and the appropriate control.
NOFEL = No observed frank effect level. The study war directed toward eliciting frank effects, but none were observed of statistical significance. Other
less severe toxic effects may have been present but were not Investigated.
FEL = Frank effect level. That exposure level which produces unmistakable adverse effects or gross toxldty, such as Irreversible functional Impairment
or mortality, at a statistically significant Increase 1n frequency or severity between an exposed population and Us appropriate control.
-------
' - r">—:'"-,nr—ita! Protection Agency
f . y
2.,: Li:.... •' Dt-ii'l/orn Street
Chicago, Illinois 60604 , :..&
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