Health risks during furniture stripping using ...

1 Figure 1: Local exhaust ventilation systemIntroductionThis information sheet is one of a series prepared byHSE s Woodworking National Interest (DCM), also known as methylenechloride, is a very effective solvent. This informationsheet is concerned only with its use as a paint stripperfor wood. Other chemicals are commonly used for paintstripping, for example caustic soda mixtures, but theseare not covered here. No chemical is safe ; all should beused with care, taking account of the advice of thesupplier. If in doubt, consult your local office of HSE. The processDCM is typically used as a component of proprietarypaint strippers. It can be used as a gel (for brushapplication) or in a dip tank.

2 In all cases, the solvent isallowed to soften the paint film, which is then removedby hand brushing/scraping. With a dip tank process,articles are often dipped in tanks (these may be heated)containing weak acid or alkali solutions, which follow thesolvent dip. Finally articles are washed to remove solvent and paintdebris. High-pressure water jets are sometimes are the hazards to Health ?Breathing in DCM vapour can produce narcotic include drowsiness, headache, giddiness and, athigh concentrations, unconsciousness and death. Skinand eye contact should be avoided since DCM is adefatting agent and exposure may cause evaporates easily producing high concentrations ofvapour, particularly in confined spaces or whereventilation is has been classified as a Category 3 carcinogen inthe European Community.

3 Under the Chemicals (HazardInformation and Packaging) (CHIP) Regulations1it hasthe risk phrase R40 Possible risk of irreversible effects .Note:Category 3 substances under the CHIPR egulations are those which give cause for concern,owing to possible carcinogenic effects, but in respect ofwhich the information available is not adequate formaking a satisfactory are your legal duties as an employer?The Control of Substances Hazardous to Health (COSHH) Regulations require you to:lidentify any hazardous substances which youremployees may be exposed to at work;lassess the risks involved in using such substancesin your process;lprevent or control exposure to such substances.

4 Inthe case of DCM if it is not reasonably practicableto prevent exposure, then control should beadequate. For exposure by inhalation, levels ofDCM in air should be reduced as low as isreasonably practicable but should in any case bebelow the maximum exposure limit of 100 parts permillion (ppm) 8-hour time weighted average; andlprovide information, training and instruction toemployees on the hazards involved and theprecautions which should be should carry out an assessment of your process:this may be recorded and should be updated asnecessary. The supplier of the paint stripper has a dutyto provide the information you need about the chemicalsyou are using , but the assessment you write should berelated to your own operation and premises and shouldinclude all substances hazardous to Health , not risks during furniture strippingusing dichloromethane (DCM)HSE information sheetWoodworking Sheet No 19 (Revised)Figure2.

5 Dipp ing tank for furn itur estrip pingThis sheet can not give you all the informatio nyou ne edabout the gene ral requ irem ents of the COSHHR egulation s, but HSE ha spubl ished ,3,4,5 and6 PreventingexposureYou can preven texpo sure by choosi ng apai nt strip perwhich does no tco ntain DCM or by usi ng a non-chemical met ho d, forexam ple ab rasi on. How ever, an ychemical which will dissolve apai nt film islike ly tohavean effect onhea lth .These effects may be less we llknown tha ntho se asso cia ted wi th DCM, which has bee nwidely studie have sh own that go od wo rki ng practices canreduce exp osu re levels sig nifi cantly.

6 Aseries ofmeasures will benee de d, the most imp ortan tof wh ich isawell-design ed ven tilation system ,includ ing go odgeneral vent ilat ion. Howe ver, wor kin gmetho ds are alsocrucial as theeffe ct of, for exam ple ,lip extraction ca nbelost if work is don eoutside the influe nce of theloca lexhaust ve nt ilatio n(LEV). Abso rpti on thro ugh the skincan be cont rolle dbygoo dwo rki ng me thods andprotective clot hin egood ge ner alventila tion (usi ngme chani cal fans) and LEV(unl ess work is infrequent/int ermittent ).Smallarticl es coul dbe stripped in asi mpl epur pose- bu iltboot h; large ar ticle sinaspray bo oth ifoneis ava ilab exhau st ven tilat ion system isillustrat ed inFi gur ce ar ea of exposed gel to themi nimum.

7 Keep sol vent cans cl ose dan duse spi ll-WE LLDE SIGN EDVEN TI LATI ON(GENER ALAN D/ORLOC AL)GOODWOR KINGME TH ODSSU ITABLEPR OTEC TIVEEQ UIPMEN T++CONTR OLOF EXPOSURE resistant containers. Keep solvent-contaminatedrags/wipes and waste in closed tankVentilation - All tanks should be fitted with effective ,8 General mechanical ventilation should beinstalled to provide make up air. This should bedesigned to operate in conjunction with LEV at thetanks. Where possible, a separate ventilated areashould be set aside for drying finished articles. Control inthe dipping area will also be improved by enclosing thesides and top of the tank (see Figure 2).

8 Working methods- The bath layout should be designedto minimise transfer distances and to allow a linear paththrough the process. If possible, mechanical lifting gearand workpiece support should be provided for tools should be used for scraping andbath cleaning. All solvent wet items should be storedwithin the influence of the LEV or in closed containerswhich can be opened within the influence of the should be provided with drip simple pump or syphon system should be used toreplenish the bath and to flow stripper over workpiecesin the bath so that the operator need not reach into thetank to bale solvent over workpieces. Only one personshould work at the stripping bath at a time, minimisingsolvent wash tanks which follow the solvent tank shouldbe kept at the lowest suitable temperature to limitsolvent tanks should be covered when not in avoid high continuous exposures, workers should notspend all their time on one stage of the process.

9 No oneshould work alone in an immersion stripping should always be someone close by who is ableto give assistance in an equipment for employeesPersonal protective equipment should be provided andworn as required by the Personal Protective Equipmentat Work Regulations minimum protectiveequipment requirements for anyone working with DCMare impermeable overalls, apron, footwear, long glovesand gauntlets and chemically resistant goggles or supplier will advise on materials suitable for usewith addition, respiratory protective equipment is requiredunless it can be demonstrated that exposure is belowthe maximum exposure limit of 100 ppm and does notexceed the current short-term guidance value of 250ppm over any 10 minute should be either:la full face mask to EN136 or BS7355 (typeapproved) with a type approved AX canistersuitable for use with DCM; orlcompressed air supplied equipment.

10 A lightweightair-fed visor may be suitable (check with yourequipment supplier that it is suitable for use withDCM).When a compressor is used as the source of supply forbreathing air, special considerations are necessary toensure adequate air supplies of acceptable samplingYou will need to measure solvent vapour in air:lto show that your control measures are effective;lto decide whether or not you need to providerespiratory protective your customers at risk?Freshly stripped items which are not properly aired andare then carried in a closed vehicle could present a are more vulnerable to the effects of solventvapour than not allow customers to take home freshly treatedarticles, especially furniture with cupboards or drawers,which are difficult to air and items with a lot of filler whichcan absorb risks you should considerWhen DCM burns it produces corrosive and toxicvapours.