LOG HOMECONSTRUCTION ANDMAINTENANCE TIPS:

HOW TO PREVENT DECAY AND INSECTS

J. Frederick AllenDirector

LOG HOME CONSTRUCTIONAND MAINTENANCE TIPS:

HOW TO PREVENT DECAY AND INSECTS

BY

TERRY S. PRICE1, LONNIE H. WILLIAMS2,AND TERRY L. AMBURGEY3

INTRODUCTION

Log houses have again become popular throughoutthe South. Personal experience and numerous inquiriesfrom owners of log homes indicate that many of thesehomes are highly susceptible to damage by decay fungiand insects. In most instances, the problems occur be-cause of combinations of three factors – the type of logsused in construction, designs that so not protect logs fromrainwetting, and lack of maintenance of exterior wall sur-faces.

Most of the historic log surfaces in the South wereconstructed of the durable heartwood of relatively large,slow-grown trees, whereas most modern log homes areconstructed of logs from small diameter, fast-grown treesconsisting of sapwood that is susceptible to decay fungiand insects. Also, many of the older log structures weresingle-story and featured wide roof overhangs and longporches that protected logs from weather. Many modernlog homes are two story, have very short roof overhangs,and have few porches. While these design features areacceptable in northern climates, they do not sufficientlyprotect the exterior log surfaces of homes in warm, hu-mid, southern climates more favorable to decay. Experi-ence has shown that the use of unfinished, untreated sap-wood siding or logs on the exterior of buildings in theSouth whose walls are not protected by porches or roofoverhangs almost invariably leads to attack by insectsand decay fungi.

1/Entomologist, Georgia Forestry Commission, Macon, GA2/Principal Entomologist, USDA Forest Service, Southern ForestExperiment Station, Gulfport, MS3/Professor and Wood Decay Specialist, Forest Products Laboratory,Mississippi State University, Mississippi State, MS

PREVENTING DECAY AND INSECTSBY PROPER LOG HANDLING

Decay and Insect Prevention Beginswith the Manufacturer

Many problems with decay and insects could beeliminated by utilizing logs rapidly and by protectingthem during seasoning and storage. Rapid utilizationrequires removing the logs from the woods and de-barking them as soon as possible after cutting. Forboth fungi and insects, colonization of logs is lesslikely if trees and logs are cut in late fall and winter.

Logs that are left unprotected for several weeksafter being cut often become colonized by a variety offungi. These logs usually can be recognized by exam-ining the ends for discolorations, often wedge-shaped,caused by stain fungi. The ends of logs that are usedrapidly and are protected from fungi during seasoningwill be free of irregular-shaped discolorations.

After logs are removed from the woods and de-barked, they should be dipped in a preservativechemical and stored off the ground, preferably undera roof, to dry air. This chemical treatment is only de-signed to protect the logs while they dry, not to pro-vide permanent protection. It is very hazardous to con-struct log homes from small-diameter, unseasonedlogs or logs that have not been debarked.

Fig. 1. Blue staining fungi. (USFS Photo)

Some log home manufacturers prefer to kiln-dry,or at least partially kiln-dry, their logs after debarkingthem. This is a good practice, provided that the kiln-dried logs are protected from being rewetted duringstorage. Temperatures reached during kiln-dryingshould be high enough to kill beetle larvae and fungiin logs.

Other manufacturers have their log-kits fumigatedwith toxic gases. Fumigation provides no long-last-ing protection and does not necessarily ensureagainst beetle infestations. Beetles and fungi mayinfest unseasoned, fumigates wood within days aftertreatment.

Practices for handling and storing logs should beadapted to the specific preservative treatment pro-cedures being used.1 Procedures now being usedinclude: superficial dip treatment of unseasoned logsin fungicides to control molds and stain fungi, dip treat-ment of unseasoned logs in diffusible chemicals tocontrol insects and decay fungi, and pressure treat-ment of seasoned logs to control insects and decayfungi. Logs treated by all of these procedures willrequire the application of maintenance treatments tothe exterior walls of homes constructs from them.However, the combination of chemicals and frequencyof treatment will vary depending on procedures usedduring manufacture.

Non-diffusible chemicals used for dip treatmentprimarily coat the surface of unseasoned logs andonly slightly penetrate seasoned ones. Diffusiblechemicals (e.g., borates), can penetrate deeply intounseasoned logs when used for dip treating and canpenetrate deeply into unseasoned or seasoned logswhen used in pressure treatments. The water-bornepreservatives used to pressure treat logs (e.g.,chromated copper arsenate and zinc naphthenate)can penetrate deeply into seasoned logs; unfortu-nately, some manufacturers attempt to treat unsea-soned logs with these preservatives.

Diffusible chemicals (borates) move through thewater in unseasoned wood from area of high con-centration on the surface to one of lower concentra-tion within wood. Penetration is best when woodmoisture content is high. An advantage to the buyer

1/Log home construction and maintenance: Preventing Decay and In-sect Problems by Terry L. Amburgey and Lonnie H. Williams, Missis-sippi State University Bulletin in Preparation.

of borate-treated logs is that the depth of penetrationcan be verified by simple color-reaction tests. Moredetails about these tests and the diffusion processare available in videotapes in ½ inch VHS format(USFS).1

1/ Write to: William H. Sites, USDA Forest Service, Region 8, ForestPest Management, P.O. Box 2680, Ashville, NC 28802, for self addressed,postage-paid video tape request form.

Fig. 2. Wood samples treated with Tim-Bor®, an EPA reg-istered wood preservative. The color graduation fromthe surface to the center of the wood indicates theextent of treatment. (United States Borax and Chemi-cal Corporation Photo)

PREVENTING DECAY

By Using Building Designs and ConstructionTechniques that Keep Logs Dry

Assuming that sound logs are delivered to thebuilding site, decay can be prevented by use of build-ing designs and construction techniques that protectlogs from excessive wetting. Wide roof overhangsand long porches, especially on the side of the struc-ture most frequently exposed to wind-blown rain, arevery important for keeping logs dry. It is nearly im-possible to keep the walls of two story homes dry.Wherever end grain of logs is exposed, such as win-dows, doors, and end-to-end joints of logs, it shouldbe protected from rainwetting because wood prima-rily absorbs water through the end grain. Many loghome manufacturers do not adequately protect theend grain of logs exposed at openings in the walls.Protection should include the use of preservativechemicals as well as flashing, trim, and caulking. Asin any structure, site drainage should be altered toassure that water drains away from the house on allsides.

Fig. 3. The logs in this two-story househave been stained from continualrainwetting. Roof overhangsshould be at least 24” wide to of-fer more protection. (GFC Photo)

PREVENTING DECAY

By Maintaining Exterior Log Surfaces

Variations of three types of logs are available inmodern log-home kits: (1) whole logs from small-diam-eter trees consisting primarily of sapwood, (2) squaredlogs consisting primarily of heartwood from large diam-eter trees, and (3) round logs shaped from square logsfrom large diameter trees consisting primarily of heart-wood. These types of logs vary in their degree of sus-ceptibility to fungi and insects, but all require protectivetreatments on their exposed surfaces. Special precau-tions must be taken when small-diameter, mostly sap-wood, logs are used in construction.

Fig. 4. These log ends are continually rxposedto rainwetting. (GFC Photo)

All exterior surfaces of logs should be brush – orspray – treated soon after house erection with a woodpreservative formulation that also contains a waterrepellent. Ideally, the formulation should contain botha fungicide and an insecticide because beetles thatinfest relatively dry wood in use are present in South-ern and Atlantic coastal states. Wherever wood endgrain is exposed to frequent wetting, such as at housecorners, it should be thoroughly treated. The exteriorsurfaces should be retreated after about 6 and 18months and, thereafter, at 4 – 5 year intervals. Thiswill assure that untreated wood that is exposed aswood checks and splits during seasoning will receivetreatment. Large checks and splits, especially thoseon the upper faces of logs, should be caulked follow-ing treatment to prevent entry of moisture. Theseexterior maintenance procedures also should be fol-lowed on homes fabricated from logs that have beenpressure treated with preservative to protect untreatedheartwood exposed at checks.

Wood sealers or film-forming finishes should notbe used on either the interior or exterior surfaces oflogs until at least one heating season has passed.Film forming finishes and “sealers: tend to trap mois-ture in logs and promote decay.

INDENTIFYING, PREVENTING, ANDCONTROLLING INSECT INFESTATIONS IN

LOG HOUSES

Log houses are susceptible to attack by many dif-ferent insects with very different habits. Termites mayattack nearly any wood species. Other insects willuse wood of many species, or beetle exit holes inlogs, only as nesting sites. Various beetles are themost common problem.

Beetles that Attack Freshly Cut Logs

Softwood species are most often used for loghomes, and include pine, spruce, fir, hemlock, north-ern white cedar, western redcedar, and cypress. Inwarm weather, freshly cut logs of all softwoods fre-quently are attacked within a few days after tree fell-ing be beetles commonly called buprestid or metallicwood borers (larvae are called flat-headed borers) andby long-horned beetles (adults are often called pinesawyers, larvae are called round headed borers).

Fig. 5.(A) Larva of a metallic wood boring beetle. (SFIWC Photo)

Fig. 5.(B) Adult metallic wood boring beetle. (Van Waters andRogers Photo)

Fig. 6. Larvae of the longhorned beetle. (SFIWC Photo)

These borers lay eggs in bark; eggs hatch within2 to 4 weeks. Larvae feed for a few weeks just underthe bark before boring into the log, going deeper aslogs dry (particularly the buprestids). The life cycleusually is 1 to 2 years, but larvae may feed for atleast 6 years when wood moisture is low. During eachyear, new holes appear as adults emerge.

When many holes appear in the log walls of struc-tures and homeowners hear chewing, rasping soundsor more feeding larvae within logs, they worry aboutthe permanence of their house. No one can definitelysay how many more adults might emerge or for howlong. Emerging adults cannot infest dry logs lackingbark, so infestations will die out of their own accordafter all larvae have completed their life cycles. How-ever, alarmed homeowners want immediate control;therefore fumigation is often done even though themoney could be better spent on other measure (seeold house borer, next section).

Clearly the prevention of these wood borers is theresponsibility of the manufacturer. Surface applica-tions of insecticides will not kill larvae deeply withinlogs and fumigates often do not penetrate “wet” logseffectively. Therefore, prevention is much easier thancontrol. How well prevention is achieved depends onhow quickly freshly cut logs are debarked and on howdeeply treatment chemicals penetrate into wood. Ifdebarking is delayed, larvae may be below the depththat nondiffusible chemicals will penetrate. Survivinglarvae will continue to feed and may later emerge asadults. Emerging adults do not ingest treated wood,so a quick-acting contact insecticide must be used toprevent emergence.

Ambrosia beetle adults also attack hardwood andsoftwood logs, usually before and sometimes afterdebarking. Females bore around tunnels (1/8-inch di-ameter or less) deeply across grain to lay eggs andinoculate the wood with ambrosia fungus. Tunnelslack boring dust, which is expelled, and their wallsare stained dark brown or black. It is best to debarklogs quickly; the fungus does not grow as wood driesbelow 30% moisture content. Adults sometimes at-tack erected houses, particularly when logs are wet-ted or are freshly finished with stains that contain al-coholic solvents which attract these beetles. Offspringrarely survive from such attacks.

Fig. 7. Wood boring beetles laytheir eggs in small pitswhich they chew in thebark. (SFIWC Photo)

Fig. 8. Exit holes made by adult wood boring beetles maybe oval to flattened in shape depending on thespecies. (GFC Photo)

Beetles that Attack and may ReinfestDry, Debarked Wood

Adults of a round-headed borer, commonly calledthe old house borer, are strong fliers and are at-tracted to odors from recently processed softwoods.They infest only pine, spruce, or fir when wood mois-ture content ranges from 30% to 10%. Old houseborers do not resemble adult buprestids, but the ¼to 3/8 inch oval exit holes, powder in tunnels, andchewing sounds of larvae are very similar and oftenconfused. Adults emerge during June and July inmost locations. Eggs are laid in small cracks on woodsurfaces during June through possible September.In the South, a minimum of 2 to 3 years is requiredfrom egglaying until adults emerge. Infestations inhouses less than 2 years old means the logs wereinfested before construction.

Logs infested before treatment may remaininfested when non-penetrating chemical treat-ments allow larvae to survive in untreated logcenters. These larvae emerge as adult beetlesthat chew holes without ingesting treated wood.

Fig. 9. An old house borer adult next to exit hole (USFSPhoto)

These beetles may survive to lay eggs in untreatedwood exposed in exit holes or in cracks as partiallyseasoned logs continue to dry. Unless a deeply pen-etrating treatment has been used, insecticides mustbe applies to exterior walls either before or with thescheduled water repellent preservative treatment re-quired for prevention of decay fungi. Insecticide sur-face treatments will not kill larvae deep in wood andare not recommenced for interior surfaces; finishesfurther limit effectiveness. Injection treatments intoexit holes may be effective for limited infestations in-side homes.

Heavy, widespread infestations may need to befumigated. Fumigants provide no residual protection,do not penetrate “wet” logs very well, and often fail tocontrol beetles in logs houses. But fumigation maygive immediate control and is a corrective measureaccepted by financial institutions when houses arebeing sold. Old house borer (and buprestid) larvaetend to concentrate in exterior log surfaces wheremoisture is high. Beetle exit holes and tunnels rarelycause structural damage, but moisture that accumu-lates in them promotes the growth of decay fungi.Therefore, money spent for fumigation could be moreeffectively spent for water repellent preservative plusinsecticide treatments of exterior log surfaces andfor other measures needed for long-term protectionagainst decay, old house borers, and anobiid beetles.

Fig. 10. Many of the wood boring beetles produce exit holesthat are similar in size and shape. The holes inthis photo were made by at least two separatespecies. (GFC Photo)

Anobiid beetles naturally occur throughout theSouth and may attack untreated wood in exterior logsor exposed wood in crawl spaces. Wood must havea moisture content above 13% (but preferably below20%). Pine and yellow-poplar are often attacked, butmany other hardwoods also are susceptible. Cedarand western softwoods are not attacked by the mostcommon anobidd species in the South. Anobiid in-festations in recently processed logs are limited tooccasional minor ones by species that only infest bark(these need no control).

Lyctid powderdust beetles only attack hardwoods

with large pores and 3% or more starch content.These beetles usually reinfest wood and may severelydamage sapwood portions of oak or walnut logs,sometimes used for log homes. Recently processedhardwood molding, picture framing, flooring, and fur-niture are often infested.

Anobiid – or lyctid – infested wood from old build-ings is sometimes reused for bookcases, paneling,flooring, or picture framing. If round 1/8 inch diam-eter holes and powder-filled tunnels are in such wood,it should be discarded or possibly fumigated or kiln-dried before use. Piles of fresh-looking powder on orbeneath wood suggests live larvae are present.

Fig. 11. This Anobiid beetle is widely distributed through-out the Eastern states and is the most common inthe Southeastern states. (SFIWC Photo)

Powder of anabiids feels gritty, lyctids like talcumpowder. Anobiid adults may emerge from infestedwood placed in centrally heated or air conditionedspaces, but wood moisture will be too low for survivalof small larvae. This is not true for lyctids. To kill lyctidsbefore using wood, move wood from 60 to 800 tem-peratures and store at 00F or below for at least 48hours for 1-inch-thick wood.

Fig. 12.(A) A picture frame infested with lyctid powder postbeetles. Note the talcum powder-like boringdust.

Fig. 12.(B) Adult lyctid beetle. (USFS Photos)

Insects that Use Wood as a Nesting Site

Carpenter ants, carpenter bees, and many soli-tary wasp and bee species are common in log houses.These insects are primarily a nuisance, and are notlikely to cause serious damage quickly.

Carpenter ants often nest in stumps or otherburied wood outside the home and enter homes tofind sugar or organic matter as food. Ant workers, ¼to ½ inch long and reddish brown to black, do not eatwood, but excavate shallow nests with smooth (as ifsanded) walls, preferably in moist, decaying wood.Preferred nesting sites are readily available in exte-rior log surfaces, around windows and doors, and inheartwood log centers in many houses. The nestscause only minor damage unless large colonies arepresent for several years.

If the main nest of the ants is outside, it must belocated and treated for satisfactory control. Reduc-ing moisture traps for decay prevention also reducesfavorable nest sites for ants.

Fig. 13. Carpenter ants; adult female shown with wingsremoved. Male and female reproductives havetwo pairs of membranous wings of unequal size.(Van Waters and Rogers Photo)

Adult carpenter bees resemble bumble bees.Both have yellow hair over most of their black bod-ies, but the carpenter bee differs by having a hairlessabdomen. The adult female bee bores a 3/8- to ½-inch round hole into wood, makes a right angle turn,and tunnels along the grain of the wood. Wood is notingested, but discarded out the entrance hole. Thetunnel is partitioned into cells, each containing a ballof pollen and nectar and egg. The offspring feed onthis food until mature, then all emerge through thehole made by the parent female. Young adults over-winter until April or May, feed on nectar, mate andoften reuse the tunnel where they were reared to layeggs. Reused tunnels may be several feet long. Re-peated tunneling may weaken an individual timber.

Fig. 15. Carpenter bee holes can be distinquished fromother insect holes by their size and roundedshape. (GFC Photo)

Fig. 14. A carpenter bee. Note the hairless abdomen.(GFC Photo)

Solitary wasps and bees place food and eggsin beetle exit holes in log walls and seal the hole witha “wall” of dirt. The offspring bores the small hole inthe wall of dirt to come out, often causing powdereddirt to accumulate beneath the hole. This is some-times mistaken for a beetle infestation. These insectsdo not harm wood; caulking beetle holes to preventdecay eliminates them.

Carpenter bees can be controlled by injecting rec-ommended insecticides into nests and tunnels. Dustformulations often work best. Seal treated bee holeswith a dowel rod or silicone sealer. Preventing nest-ing by bees in logs is very difficult, even pressure-treated wood is sometimes attacked. Painting fre-quently-attacked timber will sometimes discouragebees.

Termites

Log houses should not be any more susceptibleto subterranean termites than conventional housesif soil beneath and around foundations is treated be-fore construction with a recommended insecticide.(This treatment is best done by a licensed pest con-trol operator with proper equipment). The soil treat-ment creates a toxic barrier between termite colo-nies in the sol and wood in the home. For a betterbarrier, avoid earth/wood contacts and wood near soil.

Fig. 16. This beetle exit hole is being used by a solitarynesting wasp. Note the red dirt packed over theentrance. (GFC Photo)

Log houses in southern coastal regions will remainvery susceptible to drywood termites unless exte-rior logs are well-treated with a deeply penetratingchemical or treated regularly with an insecticide.Drywood termites fly to wood and need no contactwith soil to live.

Fig. 17. Wood to ground contact should be avoided at alltimes. (USFS Photo)

SUMMARY

Buying a log-kit home is like buying a new car,frequently decisions are based on appearance ratherthan long-term performances. Cars as wall as homesare not all designed and built in the same way; somewill require more maintenance than others. If the homeis chosen because of its appearance (design, floorplan, and log shape) without considering wood pro-tection, then buyers may later face high maintenancecosts.

Before choosing a log-kit, prospective buyersshould inquire about the log handling, storage, andtreating practices of several manufacturers.1 To askappropriate questions, buyers should first learn some-thing about fungi, insects, and treatments to preventthem.

For example, chemical treatments and other prac-tices used to prevent fungi and insects in unseasonedwood often are designed to protect logs during pro-cessing and construction and may not provide con-tinued protection of wood once it is seasoned and ina house. This is why design feature, log shapes, andtypes of treatments must be considered when choos-ing a log-home kit. Homeowner-applied maintenancetreatments usually will be needed for long-term pro-tection even though logs have been treated by themanufacturer. These maintenance treatments shouldinclude both an insecticide and a preservative formu-lation that contains a water repellent; the appropriatecombination depends upon the type of treatmentsapplied during manufacture.

1/The winter quarterly issues of two log home jour-nals provide directories of many manufacturers.These are: Log Home Guide for Builders and Buyers(ISSN 0707-5006) and Log Homes Annual Buyer’sGuide (ISSN 0743-7293).

APPENDIX

TREATMENTS FOR SPECIFIC PESTS OR USE SITES

For a list of labeled products by trade names, contactthe county agent or other authorized source in yourarea. Use of some products may not be permitted inyour area.

CARPENTER ANTS AND CARPENTER BEES

For injection into crevices, holes, and tunnels in wood:Formulations containing one or more of the followingactive ingredients: bendiocarb, boric acid, carbaryl,chlorpyrifos, diazinon, fenvalerate, propetamphos, orpropoxur. Many formulations with these ingredientscan also be applied as wood surface sprays.

ANOBIID BEETLES, LYCTID POWDERDUSTBEETLES, OLD HOUSE BORERS

For injection into holes and tunnels in wood withinstructures: formulations containing one or more ofthe following active ingredients: chlorpyrifos as PT270 Dursban; pyrethrins plus piperonyl; butoxide plussilica gel plus petroleum distillate as PT 230 Tri-Die,lindane as Xylamon Wood Worm Killer or XylamonLX-Hardening.

For wood surface sprays within structures:chlorpyrifos as Dursban L.O.

For surface sprays of exterior log walls: formula-tions containing one or more of the following activeingredients: 1.0% chlorpyrifos as Dursban L.O. orDursban TC, 0.5% Lindane (numerous formulations).

DRYWOOD TERMITES

For treatment of wood or galleries within struc-tures: formulations containing one or more of thefollowing active ingredients: silica gel plus ammoniumfluosilicate, pyrenthrins plus piperonyl butoxide plussilica gel plus petroleum distillate, chlorpyrifos as PT270 can be injected into galleries.

SUBTERRANEAN TERMITES

For soil treatment by certified applicators: formulationscontaining one or more of the following active ingredients:chlordane, chlorpyrifos, cypermethrin, permethrin, hep-tachlor, and isofenphos. Formulations containingbendiocarb, boric acid, chlorpyrifos, or propoxur can beinjected into galleries if specified on label.

FOR ALL THE ABOVE PESTS EXCEPT CARPENTERBEES AND SUBTERRANEAN TERMITES OTHERTHAN THE FORMOSAN SUBTERRANEAN TERMITE,FMIGATION WITH PRODUCTS CONTAINING EITHERMETHYL BROMIDE OR SULFURAL FLOURIDE CANBE CONE IF CIRCUMSTANCES WARRANT SUCHTREATMENT.

MOISTURE AND DECAY PREVENTION (exterior walls)

For brush or spray applications by homeowners – Formu-lations containing both a water repellent and a biocide suchas copper –8- quinolinolate (e.g., Woodgard II), tributylinoxide plus 2-(thiocyano-methylthio) benzothiazole plus me-thylene bis (thiocyanate) (e.g., Seal-Treat II wood preser-vative), diiodomethyl-para-tolyl-sulfone plus zincnapthenate impart water repellency but also impart a green-ish discoloration to wood.

TREATING UNSEASONED LOGS (used by individuals)

Dip-diffusion treatments with a borate (disodium octaboratetetrahydrate such as TIM-BOR) plus a fungicidal additive(diiodomethyl-para-tolyl-sulfone as Amical Flowable or 2-(thiocyano-methyltio) benzothiazole plus methylene-bis(thiocyanate) as Busan 1009, specify formulation that iscompatible with borates are recommended because deeplypenetrating protection against insects and decay fungi maybe achieved.

1/Some states have restrictions on the use of certain pesticides. Checkyour state and local regulations. Also, because registrations of pesti-cides are under constant review by the U.S. Environmental ProtectionAgency, consult your state forest agency, county agricultural agent orstate extension specialist to be sure the intended use is still registered.Trade names used in this publication are solely for the purpose of pro-viding information. Mention of a trade name does not constitute a guar-antee or warranty of the product by the Georgia Forestry Commission,USDA Forest Service or the Mississippi Cooperative Extension Serviceover other products not mentioned.

PRECAUTIONARY STATEMENT

Pesticides used improperly can be injurious to man,animals, and plants. Follow the directions and heedall precautions on the labels.

Store pesticides in their original containers under lockand keep out of reach of children and animals, andaway from food and feed.

Apply pesticides so that they do not endanger hu-mans, livestock, crops, beneficial insects, fish andwildlife. Do not apply pesticides when there is dangerof drift, when honey bees or other pollinating insectsare visiting plants, or in ways that may contaminatewater or leave illegal residues.

Avoid prolonged inhalation or pesticide sprays ordusts; wear appropriate protective clothing.

If your hands become contaminated with a pesticide,wash them immediately with soap and water. In casea pesticide is swallowed or gets in the eyes, followthe first aid treatment given on the label and getprompt medical attention. If a pesticide is spilled onyour skin or clothing, remove the clothing immedi-ately and was skin thoroughly. After handling or spray-ing pesticides, do not eat or drink until you havewashed with soap and water.

Do not clean spray equipment or dump excess spraymaterial near ponds, streams, or wells. Because it isdifficult to remove all traces of herbicide from equip-ment, do not use the same equipment for insecticidesor fungicides that you use for herbicides.

Dispose of empty pesticide containers promptly. Havethem buried at a sanitary landfill dump, or crush andbury them in a level, isolated place.