Unft«i Stat« Offic* of PmtMdm and Toxic SutMtancw
Envtronimntal Protection OHio* of P«tldd» Piegrara (TS-766C)
Agwicy MMitagton. DC 20460
Pesticide
Fact Sheet
Name of Chemical:
Reason for Issuance:
Date Issued:
_ .noA
•- ~L .. ' 1984
Fact Sheet Number:
INTRODUCTION - —
The Environmental Protection Agency issued its final regulatory
position July 11, 1984 on the use of creosote, inorganic arsenicals
and pentachlorophenol (and its salts) as wood preserving
pesticides. This regulatory action was taken under the authority
of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).
EPA's mandate under FIFRA is to prevent unreasonable adverse effects
associated with exposure to these three wood preservatives and
products treated with them, while still allowing the benefits , _
of their use to continue. This fact sheet provides the details
of the regulatory action and information on the health and safety
concerns that prompted it.
USES
Wood preservatives protect wood from decay and increase the
life expectancy of wood by a factor of five or more over that
of untreated wood. Pressure treated wood containing the pest-
icides includes railroad ties, construction lumber, plywood,
timbers, foundation materials, fence posts, and utility poles,
as well as landscape materials'. The preservatives also are
sprayed or brushed on fence posts, lumber used around the home
and yard such as wooden fences, decks, playground equipment,
and lawn furniture, and for millwork, plywood and particle-
board. In many instances, creosote, pentachlorophenol and
inorganic .arsenicals are used as alternatives to eacn other
in treating wood.
In 1982, these three wood preservatives comprised roughly
one-Ovird of the 2.7 billion pounds of pesticides produced for
both agricultural and industrial uses. Creosote, pentachloro-
phenol, and the inorganic arsenicals account for over 97% of the
wood preservatives used in this country. Creosote, due to its
density, accounts for most of the poundage used, but the inorganic
arsenicals are found on more treated wood products. The major
use of creosote is on railroad ties and utility poles. Penta-
chloropnenol is used primarily for poles, posts, fences, crossarms
and logs for log homes. Sodium and .potassium pentachlorophenate
are used for preservation of freshly peeled poles or posts during
air seasoning prior to pressure-treatment and for green lumber.
Inorganic arsenicals are most commonly used on treated wood
found outside the home (e.g.,decks). The inorganic arsenicals
include chromated copper arsenate (CCA), ammoniacal copper arsenate
(ACA) and fluor chrome arsenic phenol (FCAP).
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REGULATORY HISTORY
On October 18, 1978, the Environmental Protection Agency
initiated a special review (Rebuttable Presumption Against
Registration or RPA.R) of the pesticidal uses of creosote, penta—
chiorophenol (and its salts), and the inorganic arsenica]s based
on health concerns. All three wood preservatives exceeded EPA ’s
risk criteria for t,. or production. In ad ttion, creosote and
the inorganic arsenicals were associated with genetic changes,
and pentachiorophenol and the inorganic arsenicals were linked
to defects in the offspring of laboratory animals.
In 1981, EPA proposed a set of regulatory actions for safe
and proper commercial and domestic application of wood preserva-
tives and recommended regulatory action for safe use and handling
of treated wood by conswners. These proposals were reviewed by
several government agencies and other interested parties, including
industry and environmental groups.
The Agency held a public meeting on April 14, 1983, to give
the public an opportunity to comment on a modified proposal to
conclude the RPAR. Industry, environmental groups and other
interested parties submitted eQmwents as a result of that meeting.
In reaching the final regulatory position, the benefits
of using wood preservatives and the availability and efficacyof
alternatives (including other chemicals and non—wood products)
were taken into account. The risks to applicators during the
application process as well as the risks to the general public
resulting from using, handling or disposThg of the treated
wood were examined.
In general, the risks to persons applying these chemicals
are more significant than for persons who are only exposed to
treated wood. Common uses of treated wood such as decks, lawn
furniture or playground equipment do not pose high risks of
adverse effects, and there are practical steps that can be taken
to reduce exposure to already—treated wood. The consumer
information materials developed in connection with this decision
point out that the use of appropriate sealers will reduce derma].
exposure or inhalation exposure from indoor uses ot wood treated
with pentachioropheflol or creosote.
ACTIONS
The Environmental Protection Agency has placed several
restrictions on the application of the wood preservatives
creosote, pentachiorophenol and its salts (including sodium
pentachlorophenate) and the inorganic arsenicals. The actions
are described below.
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1. RESTRICTIONS ON WHO MAY APPLY WOOt PRESEPVA IVE5
All three chemicals are now class2fied for restricted u e
only by certified applicators (or someone under their direct
supervision) except for the brush—on treatment of the inorganic
arsenica]s where use will be for commercia construction purposes
only and not for household use. This action will reduce the
general availability of wood preservatives to home and farn
users, but an individual who chooses to use these products may
do so by obtaining training and certific tion from the appropriate
State agency. This provision is designed to ensure that restricted
pesticides are properly applied by persons trained to safely
handle these materials.
2. USE AND APPLICATION OF WOOD PRESERVATIVES: L.AEEL CHANGES
The following are the significant label changes that will
be required:
The label must state: Restricted Use Pesticide: For sale
and use only by certified applicators or by persons under tne r
direct supervision and only for those uses covered by tne certified
applicator’s certification.
Al ], pentachiorophenol products must include a warning that
exposure to women during pregnancy should be avoided becauses
pentachiorophenol has been shown to cause defects in the offspring
of laboratory animals.
Protective clothing requirements will be specified. These
will include use of impermeable gloves for applying the preserva-
tives and in all situations where derma] contact is expected (e.g..
han4 ing freshly treated wood and manually opening cylinders to
press!ure treatment equipment). In certain situations such as
sprayng the chemicals and working around pressure treatment
equipment, additional clothing is required. Such clothing
would include overBlls, 3acket, boots, respirators. goggles
and head covering. Applicators at commercial sites must leave
their protective clothing at the plant. For home and fart use,
non—disposable protective clothing should be laundered separately
from other clothing.
All exposed arsenic treatment plant workers will be required
to wear a respirator if the level of ambient arsenic is unknown
or exceeds a Permissible Exposure Limit (PEL)of 10 ug/m 3
averaged over an 8 hour work day. This PEL is the same as the
standard required by the Occupational Safety and Health Adminx-
strat ion.
To reduce exposure to pentachiorophenol. closed systems
for mixing and emptying powdered/prilled (granular) formulations
will be required within three years. This phase—in period will
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allow small wood treatment operations which otter lack closed
Systems to comply without undue economic hardship. Closed systems
for mixing powdered inorganic arsenicals will be immediately
required because of an unacceptably high risk of t .v or production.
Applicators may not eat, drink, or use tobacco products
during the application process, which may expose therT to the
treatment formulations. They must wash thoroughly after skin
contact and before eating, drinking, smoking or usinç restrooms.
Pentachlorophenol and creosote may ot be applied in homes.
Pentachiorophenol may not be applied to wood intended for use in
interiors, except for miliwork (with outdoor surfaces) and support
structures which are in contact with the soil in barns, stables
and similar sites and which are subject to decay or insect infes-
tation. A sealer must be applied, however.
Creosote may not be applied to wood intended for use in
interiors except for those support structures which are in contact
with the soil in barns, stables and similar sites and which are
Sub ect to decay or insect infestation. A sealer must be applied.
The application of pentachiorophenol to logs for constructior.
of log homes is prohibited.
If creosote or pentachiorophenol is applied to wood intended
for use where it will frequently Contact bare skin (e.c., on outdoor
furniture), two coats of anappropriate sealer must be applied.
Urethane, epoxy and shellac re acceptable scalers f or all
creosote—treated wood. Urethane, shellac, latex epoxy enamel,
and varnish are acceptable sealer. for pentachiorophenol—treated
wood, Ars.niCallYtreated wood without sealers is safe for
frequent contact because absorption through the skin is negligible.
.P.ntachlor oPheflol or creosote should not be used where there
may s.contaminatiOfl of feed, food, drinking or irrigation water.
3. USE OF PRESSURE-TREATED WOOD: CONSUMER AWARENESS PRO RAP
The Consumer Awareness Program will require wood pressure-
treaters to send Consumer Information Sheets to all places where
treated wood is sold to instruct consLmters about handling prc-
cedures, such as the use of protective gloves and coveralls anc
face masks when sawing treated wood products. The information
sheet will recommend against the use of wood treated with any
of the three preservatives in proximity to food, feed and public
drinking water.
In interiors of farm buildings where domestic animals are
unlikely to lick or bite the wood, pentachiorophenol and creoaote
may be used if two coats of an approved sealant are applied. In
general, shavings, sawdust, and the treated wood itself should not
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be used for bedding, brooding facilities, food containers, etc.
The information sheet viii also recommend that consumers avoid
frequent and prolonged skin contact with pentachlorephenoi and creo-
sote—treated wood such as treated lawn chairs and other outdoor
furniture, unless two coats of an •ffective sealer have been applied.
All treated wood must be visibly clean and free of surface residue
for use on patios, decks and walkways.
The use of pentachlorophenol pressure—treated wood in a home
is prohibited except for laminated beams orbuilding structures
in ‘ co t.ct with the ground, provided - tbat two coats of an sppro-
priats ea1.r .r. ppli.d. b. ose of eo.o -treated . d
ifla ide ‘the bouie is prohibited. ‘Wood pressure—treated with srse lca1
preservatives amy be used inside residences if dust is vacui. .d
from the wood surface.
?reated -wood may be disposed of by ordinary trash collection
or by burial. it should not be burned in a fireplace or open fire
because of the toxic fumes or ashes thatmay be produced. (Coinmer—
cial users such as railroad workers may use industrial incinerators
to burn railroad ties——at these higher temperatures, toxic chemicals
are broken down).
4. DIOXIN CONTENT OP PENTACHLORP HENOL
Registrants of pentachloropbenoi will be required to limit
immediately the dioxin contaminant (hexachlorodibenzo—p—dioxiru or
RxCDD) in pentachlorophenol and its salts to 15 ppm and reduce
that level to 1 ppm or less within 18 months. BxCDD causes
tumors in rats and mice. The highly toxic dioxin TCDD has not
been found in pentachiorophenol. and no TCDD wil be allowed in
the product.
5. DATA REQUIREMENTS
Manufacturers who market or intend to market wood preservatives
must submit the following information:
For technical product registrations of pentachiorophenol
and sodium pentachiorophenat., a description of the manu-
facturing process, including any changes to lower BxCDD;
product identity; data on the analysis and certification
of product ingredients: and information on the technical
feasibility and costs of reducing HxCDD lower than the 1
ppm limit.
Epidemiology and exposure monitoring studies of creosote
treatment plant workers so that, upon receipt of the data,
the Agency can quantitatively estimate the potential risk
of cancer.
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