Review Summary, Copper Chrome Arsenate (CCA)

72 Pages·2005·0.7 MB·English

The Reconsideration of Registrations of Arsenic Timber Treatment Products
(CCA and arsenic trioxide) and Their Associated Labels

REPORT OF REVIEW FINDINGS AND REGULATORY OUTCOMES
SUMMARY REPORT

Review Series 3

March 2005

Australian Pesticides &
Veterinary Medicines Authority

Canberra
Australia
© This work is copyright 2005. Apart from any use permitted under the Copyright Act 1968, no
part may be reproduced without permission from the Australian Pesticides and Veterinary
Medicines Authority.

ISSN 1448-1553

This review report for the arsenic timber treatment products, copper chrome arsenate (CCA) and
arsenic trioxide, is published by the Australian Pesticides and Veterinary Medicines Authority.
For further information about this review or the Pesticides Review Program, contact:

Manager Pesticides Review
Australian Pesticides and Veterinary Medicines Authority
PO Box E240
KINGSTON ACT 2604
Australia

Telephone: [phone]
Facsimile: 61 2 6272 3218
Email: [email protected]
APVMA web site: http://www.apvma.gov.au
Australian Pesticides and Veterinary Medicines Authority (APVMA)
FOREWORD
The APVMA is an independent statutory authority with responsibility for the regulation of
agricultural and veterinary chemicals in Australia. Its statutory powers are provided in the
Agricultural and Veterinary Chemicals Code Act, 1994 (Agvet Codes).
The APVMA can reconsider the approval of active constituents, the registration of chemical
products or the approval of labels for containers of chemical products at any time. This is outlined
in Part 2, Division 4 of the Agvet Codes.
The basis for the reconsideration is whether the APVMA is satisfied that continued use of arsenic
timber treatments, copper chrome arsenate (CCA) and arsenic trioxide in accordance with the
instructions for their use:
• would not be an undue hazard to the safety of people exposed to it during its handling; and
• would not be likely to have an effect that is harmful to human beings; and
• would not be likely have an unintended effect that is harmful to animals, plants or things or
to the environment.
The requirements for continued approval of a label for containers for a chemical product are that
the label contains adequate instructions. Such instructions include:
• the circumstances in which the product should be used;
• how the product should be used;
• times when the product should be used;
• frequency of the use of the product;
• the withholding period after the use of the product;
• disposal of the product and its container;
• safe handling of the product.
A reconsideration may be initiated when new research or evidence has raised concerns about the
use or safety of a particular chemical, a product or its label.
The process for reconsideration includes a call for information from a variety of sources, a review
of that information and, following public consultation, a decision about the future use of the
chemical or product. The outcome always involves the APVMA using its legislative powers for
finalising a reconsideration as set out in the legislation (refer part 1.4 of this report). On occasions,
however, issues raised in the review lead the APVMA to exercise regulatory powers that are
outside the scope of its reconsideration powers but address the issues raised in the course of the
review, for example taking steps to have a chemical product declared to be a restricted chemical
product.
In undertaking reviews, the APVMA works in close cooperation with the Office of Chemical
Safety (OCS–public health and OCS-OHS) within the department of Health and Ageing, the
Department of Environment and Heritage (DEH), and State Departments of Agriculture as well as
other expert advisors, as appropriate.
The APVMA has a policy of encouraging openness and transparency in its activities and
community involvement in decision-making. The publication of review reports is a part of that
process.
The APVMA also makes these reports available to the regulatory agencies of other countries as
part of bilateral agreements. Under this program it is proposed that countries receiving these
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Australian Pesticides and Veterinary Medicines Authority (APVMA)
reports will not utilise them for registration purposes unless they are also provided with the raw
data from the relevant applicant.
This document The reconsideration of registrations of arsenic timber treatment products (CCA
and arsenic trioxide) and their associated labels relates to all products containing CCA and
arsenic trioxide. The review’s findings and regulatory outcomes are based on information
collected from a variety of sources. The information and technical data required by the APVMA
to review the safety of both new and existing chemical products must be derived according to
accepted scientific principles, as must the methods of assessment undertaken.
The review report containing the APVMA summary assessments (The reconsideration of
registrations of arsenic timber treatment products (CCA and arsenic trioxide) and their associated
labels. Volume I, Review Findings and Regulatory Outcomes) and the detailed technical
assessments (The reconsideration of registrations of arsenic timber treatment products (CCA and
arsenic trioxide) and their associated labels. Volume II, Technical Report) is available from the
APVMA website: http://www.apvma.gov.au/chemrev/chemrev.html.

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Australian Pesticides and Veterinary Medicines Authority (APVMA)
ACRONYMS AND ABBREVIATIONS

ACVM New Zealand Agricultural Compounds & Veterinary Medicines Group
ADI Acceptable Daily Intake
ADWG Australian Drinking Water Guidelines
ai active ingredient
APVMA Australian Pesticides and Veterinary Medicines Authority
ARfD Acute Reference Dose
ATDS Australia Total Diet Survey
CCA Copper Chrome Arsenate
Codex FAO/WHO Codex Alimentarius Commission
DEH Department of Environment and Heritage (previously Environment Australia)
DMA dimethylarsenic acid
ERMA Environmental Risk Management Authority (New Zealand)
FSANZ Food Standards Australia New Zealand
IARC International Agency for Research on Cancer
IPCS International Programme on Chemical Safety
JECFA Joint Expert Committee on Food Additives
JMPR Joint FAO/WHO Meeting on Pesticide Residues
LD The dose at which 50% of a test population dies
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LOAEL Lowest Observed Adverse Effect Level
LOD Limit of Detection
LOEL Lowest Observed Effect Level
LOQ Limit of analytical Quantitation, also referred to as limit of determination
LOR Limit of Reporting
MMA monomethylarsenic acid
MOE Margin of Exposure
NEDI National Estimated Dietary Intake
NEPC National Environmental Protection Council
NESTI National Estimated Short-Term Intake
NHMRC National Health and Medical Research Council
NOEL No Observed Effect Level
NOHSC National Occupational Health and Safety Commission (The OH&S unit has now been incorporated
into the Office of Chemical Safety as the OCS – OHS unit)
OCS Office of Chemical Safety (now OCS – Public Health), within the Dept of Health & Ageing
OECD Organisation for Economic Cooperation and Development
OHS Occupational Health and Safety
PACSC Pesticide and Agricultural Chemical Standing Committee
PHED Pesticide Handlers Exposure Database
PMRA Pest Management Regulatory Agency (Canada)
POEM Predictive Operator Exposure Model
PPE Personal Protective Equipment
RTECS Registry of Toxic Effects of Chemical Substances
TC Transfer Coefficient
TDI Tolerable Daily Intake
US CPSC United States Consumer Product Safety Commission
USEPA United States Environmental Protection Agency
WHO World Health Organisation

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Australian Pesticides and Veterinary Medicines Authority (APVMA)
TABLE OF CONTENTS
TABLE OF CONTENTS EXECUTIVE SUMMARY.............................................................6
EXECUTIVE SUMMARY.........................................................................................................9
EXECUTIVE SUMMARY.........................................................................................................9
INTRODUCTION...........................................................................................................................................9
TOXICOLOGICAL ASSESSMENT.................................................................................................................9
ENVIRONMENTAL ASSESSMENT..............................................................................................................11
OCCUPATIONAL HEALTH & SAFETY ASSESSMENT................................................................................12
ADEQUACY OF LABEL INSTRUCTIONS.....................................................................................................12
PUBLIC CONSULTATION...........................................................................................................................13
REVIEW FINDINGS AND REGULATORY OUTCOMES................................................................................13
REGULATORY FRAMEWORK....................................................................................................................14
SUPPORTING ACTION FROM OTHER AUTHORITIES................................................................................14
FATE OF EXISTING STRUCTURES.............................................................................................................14
1. INTRODUCTION............................................................................................................16
1.1 REGULATORY STATUS OF ARSENIC TIMBER TREATMENTS IN AUSTRALIA.............................16
1.2 REASONS FOR REVIEW OF ARSENIC TIMBER TREATMENTS...................................................16
1.3 SCOPE OF THE REVIEW..............................................................................................................16
1.4 REGULATORY OPTIONS..............................................................................................................17
1.5 FINDINGS OF DRAFT REVIEW REPORT......................................................................................17
CCA Timber Treatment Products............................................................................................17
Arsenic Trioxide Termite Treatments......................................................................................18
2. APPLICATION................................................................................................................18
2.1 COPPER CHROME ARSENATE....................................................................................................18
2.2 AUSTRALIAN STANDARDS PERTAINING TO APPLICATION AND USE OF CCA..........................19
2.3 PAST USE AND CURRENT ADHERENCE TO THESE STANDARDS.................................................19
2.4 APPLICATION RATES FOR CCA.................................................................................................20
2.5 ARSENIC TRIOXIDE.....................................................................................................................21
3. TOXICOLOGY ASSESSMENT SUMMARY...............................................................21
3.1 INTRODUCTION...................................................................................................................................21
3.2 HAZARD AND RISK ASSESSMENT......................................................................................................21
3.2.1 Arsenic............................................................................................................................21
Playground-related exposure................................................................................................26
3.2.2 Copper............................................................................................................................30
3.2.3 Chromium......................................................................................................................31
3.3 CONCLUSIONS.............................................................................................................................33
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Australian Pesticides and Veterinary Medicines Authority (APVMA)
4. ENVIRONMENTAL ASSESSMENT SUMMARY......................................................35
4.1 INTRODUCTION...................................................................................................................................35
4.2 ENVIRONMENTAL EXPOSURE.....................................................................................................35
4.2.1 Release and method of use.......................................................................................35
4.2.2 Evidence of environmental contamination...............................................................36
4.3 ENVIRONMENTAL FATE..............................................................................................................37
4.3.1 General fate in soil and water...............................................................................37
4.3.2 Leaching of copper, chromium and arsenic from treated wood........................38
4.3.3 Field studies of CCA leaching from timber and addition to soil.......................42
4.3.4 CCA components on the surface of treated wood...............................................45
4.3.6 Consequences of timber waste production during construction........................47
4.3.7 Disposal of CCA treated wood and wood waste..................................................48
4.4 ENVIRONMENTAL EFFECTS........................................................................................................48
4.5 RISK ASSESSMENT.......................................................................................................................49
4.5.1 Risks to the environment from the CCA application process............................49
4.5.2 Risks to the environment from CCA-treated timber in service.........................49
4.5.3 Risks to the environment from disposal of -treated timber and waste.............51
4.5.4 Risks to the environment from the use of arsenic trioxide timber treatments.52
4.6 CONCLUSIONS.............................................................................................................................52
5. OCCUPATIONAL HEALTH AND SAFETY ASSESSMENT....................................52
6. PUBLIC CONSULTATION............................................................................................53
8. OVERSEAS REGULATORY STATUS.........................................................................54
9. REVIEW FINDINGS.......................................................................................................54
9.1 COPPER CHROME ARSENATE.....................................................................................................54
9.2 ARSENIC TRIOXIDE.....................................................................................................................56
9.3 REGULATORY FRAMEWORK......................................................................................................56
9.4 FATE OF EXISTING STRUCTURES................................................................................................57
10. REVIEW RECOMMENDATIONS............................................................................57
10.1 LABEL DIRECTIONS.....................................................................................................................57
10.2 AMENDMENTS TO STANDARDS...................................................................................................58
10.3 PROPOSED REGULATORY ACTIONS...........................................................................................58
11. BIBLIOGRAPHY........................................................................................................58
APPENDIX 1: PRODUCTS AND LABELS INCLUDED IN THE REVIEW................59
APPENDIX 2: LABEL INSTRUCTIONS..........................................................................60
SAFETY DIRECTIONS..........................................................................................................64
FIRST AID...............................................................................................................................64
APPENDIX 3: PUBLIC SUBMISSIONS ON THE DRAFT REVIEW REPORT.........66
Restrictions of Uses................................................................................................................66
Environmental concerns from disposal of treated-timber.................................................69
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Australian Pesticides and Veterinary Medicines Authority (APVMA)
Existing structures.................................................................................................................70
Upgrading timber treatment plants and practices..............................................................70
Improving label instructions.................................................................................................71
Worker exposure data requirements...................................................................................71
Restricted chemical product (RCP) status & training requirements................................71
Alternatives to CCA...............................................................................................................72

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Australian Pesticides and Veterinary Medicines Authority (APVMA)
EXECUTIVE SUMMARY
Introduction
Arsenic timber treatments, copper chrome arsenate (CCA) and arsenic trioxide, are used to prevent
damage to timber and timber structures by insects (termites, borers, beetles), wood rot and wood
fungus. CCA is generally used on wood intended for outdoor uses, such as telegraph poles,
decking and fencing, in landscaping and in building structures. Timber treated with CCA is also
used in residential, school and community playground equipment. Arsenic trioxide is used for
post-construction control of termites around the home. Its applied by licensed pest control
operators under carefully controlled conditions. In March 2003, the APVMA announced the
reconsideration (review) of the registrations of timber treatment products containing arsenic, and
the approval of the labels associated with those products. New information, some from overseas
and some from Australia, indicated that dislodgeable residues (that is, capable of being transferred
from treated timber through contact) on CCA-treated timber structures may be higher than
previously believed. This has possible public health implications. Other information also raised
concerns that environmental contamination may occur near sites where timber is treated with CCA
and where timber is disposed of.
The APVMA released a document entitled Arsenic Timber Treatments (CCA and Arsenic
Trioxide): Review Scope Document that detailed the reasons for the review and its scope, in March
2003. The aim of the review was to examine the potential for adverse public health effects arising
from the use of CCA or arsenic trioxide timber treatments, the potential for adverse environmental
effects from the use and disposal of these products, and the adequacy of instructions and warnings
on product labels.
The APVMA required the registrants of CCA and arsenic trioxide products to submit all the
relevant scientific data and information for the review and also invited public submissions. The
APVMA, in collaboration with the Office of Chemical Safety (OCS), and the Department of
Environment and Heritage (DEH), assessed the data and information received from the registrants,
public submissions, scientific literature, archival holdings and reviews by overseas regulatory
authorities.
In assessing the data and information, the APVMA also consulted widely with the registrants,
representatives of the timber treatment industry, relevant State and Federal departments, Standards
Australia, the Australian Building Codes Board, local government and planning authorities, parks
and wildlife agencies, the CSIRO and the community. Further, it also conferred with the US
Environmental Protection Agency (USEPA).
This document summarises the review findings and regulatory outcomes. The technical
assessments are detailed in full in a separate document entitled The Reconsideration of
registrations of arsenic timber treatment products (CCA and arsenic trioxide) and their associated
labels. Technical Report (available on the APVMA website www.apvma.gov.au).
Toxicological assessment
The APVMA sought expert toxicological advice from the Office of Chemical Safety (OCS), in the
Department of Health and Ageing, on the potential for adverse public health effects arising from
the use of CCA or arsenic trioxide and the adequacy of instructions and warnings on product
labels. The OCS considered all data that was relevant to the review.
The toxicological assessment examined the inherent toxic hazards of CCA and arsenic trioxide and
subsequent risk to health from exposure to these chemicals. The APVMA must be satisfied that
use of CCA and arsenic trioxide would not be likely to have an effect that is harmful to human
beings and would not be an undue hazard to the safety of people using anything containing their
residues.
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Australian Pesticides and Veterinary Medicines Authority (APVMA)
CCA
CCA consists of three active constituents, copper, chromium and arsenic. The arsenic primarily
protects timber against insects, while copper acts as a fungicide, and chromium “fixes” these two
chemicals in the timber. Although these components are reported to be fixed during the treatment
process, some release does occur when the treated timber is in service. Therefore, the public can
potentially be exposed to dislodgeable residues from contact with treated timber, either by
absorption through the skin or by unintended ingestion through the mouth.
Copper, chromium and arsenic are present naturally in the environment at low levels (in air, food,
water and soil). Therefore, the public is exposed to these chemicals through sources other than
CCA treated-timber.
The toxicological assessment found that copper and chromium in the treated timber do not present
an undue risk to public health because estimated exposure levels are below safety thresholds. The
level of risk from timber-sourced arsenic is less certain.
The toxicological assessment aimed to determine whether arsenic that may be present in the
dislodgeable residues on CCA-treated timber structures, or in surrounding topsoil, poses an
unacceptable risk for public health, particularly for children. Treated structures where children
could have frequent and intimate contact such as playground equipment, decks, handrails and
picnic tables are sources of highest probable exposure. Young children, aged 3-5 years, are
considered to be the most at-risk group because they typically display substantial hand-to-mouth
behaviour.
The World Health Organisation has set an intake of 2 µg (micrograms) of arsenic per day as the
tolerable intake per kilogram of body weight (the tolerable intake is the amount of the chemical
which can be ingested daily without any appreciable health risk for a lifetime of exposure). The
Food Standards Australia New Zealand (FSANZ) set the tolerable intake at 3 µg per day per
kilogram of body weight for Australia. The Australian aggregate estimate for inorganic arsenic
intake from natural sources by an average 3-5 year old child is 0.5 µg per day per kilogram of
body weight. Therefore, the key issue in relation to CCA-treated timber is whether the additional
exposure to arsenic that may arise from dislodgeable residues from timber structures can increase
the total intake of arsenic above the safety threshold. To address this issue, data was required to
answer the following key questions:
a) How much dislodgeable arsenic is present on timber structures treated with CCA?
b) How much arsenic is likely to adhere to children’s hands and other parts of the body?
c) What fraction of such adhered arsenic is likely to be transferred to the mouth or absorbed
through the skin?
The Review found that scientific data available for assessment were not of sufficient scientific
quality or scope to answer the above questions for Australian conditions, particularly where there
was likely to be frequent and intimate contact with treated timber.
There was data from a USA study that could be adapted for Australian situations to answer
questions (b) and (c). However, there were no studies, which could be demonstrated to be relevant
to Australia, to estimate the quantities of dislodgeable arsenic on the timber structures treated with
CCA (question (a)).
Of the information available to the review that measured dislodgeable arsenic, there was only one
study that was conducted under controlled conditions and was of sufficient scientific quality for
regulatory purposes. However, this study was based on a very small sample set (17 studies) taken
from a single city in the USA. Other available studies, including one from Australia, were very
limited in scope. While these other studies indicated that arsenic is released from CCA-treated
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