Guidelines for the Management of Lead-Based Paint
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6 RECOMMENDED WORKING PRACTICES
6.1 Introduction
If lead-based paint is present in a house, it is not necessarily a danger to health. Indeed, removing it is likely to cause a greater risk of exposure than leaving it in place and monitoring its effects.
Basically, where lead-based paint is identified, there are two options:
- If it is in good condition, overcoat it using a non-hazardous surface coating or lining.
- If it presents a danger to health due to its position or condition, remove it and redecorate with a non-hazardous surface coating or lining.
It must be stressed that overcoating with a non-hazardous surface coating is not a permanent solution. It is unsuitable for situations where the lead-based paint layer may be flaking due to loss of adhesion or has been damaged. It is also unsuitable in situations where surfaces can be chewed by children or animals (eg, door architraves, window sills, door handles or items that children can reach or put into their mouths).
Note: For the purposes of this guideline 'overcoating' is defined as a process that reduces access to lead-based paint by providing a barrier between the lead-based paint and the environment. This barrier can be formed by a surface coating (or lining) which is bonded to the surface by itself or through the use of an adhesive.
The most common overcoating will be paint which meets current requirements as to lead content. Where paint is used, it is essential that the new top coat is light in colour to prevent undue thermal stress on the underlying coats.
Overcoating should be effective in preventing exposure to lead in paint, but only as long as the new coating remains intact. For this, good surface preparation is essential. As the coating will eventually deteriorate, it should be maintained and replaced when necessary, otherwise the hazard of exposure to lead-based paint will recur.
The precautions required when preparing a painted surface for repainting are essentially the same as those for lead-based paint removal, although the amount of waste generated is likely to be less.
The only way to eliminate the hazard of lead-based paint is to remove the paint completely. This involves stripping the paint back to the underlying surface and redecorating with a non-hazard surface coating. This is a permanent solution. Alternatively, building components painted with lead-based paint, such as windows and doors, can be replaced during renovation or remodelling.
Note: While most paint removal processes will effectively remove the paint from a wooden surface, lead contamination will remain in the timber.
The following sections describe safe surface preparation and redecoration methods for the overcoating and removal of lead-based paint. The overall task sequence for indoor and outdoor operations is summarised in Figures 1 and 2. Specific information about the different paint removal methods is given in Tables 1 and 2.
6.2 Before working
Assume that the paint to be removed is lead-based unless it is known not to be. Use the sodium sulphide test (described in section 9.2 of this guideline) if necessary. For lead-based paint removal, use the following safe system of work:
- Ensure occupants, particularly children and pets, are not exposed in any way to the hazard. It may be necessary to arrange for the house to be vacated before work proceeds.
- Keep children and pets away from the work area and make sure they do not eat or play with paint debris.
6.3 Procedures for paint removal
The risks of lead contamination depend on the extent of surface preparation, the scale of the work, and the paint removal method to be used. Power sanding devices, unless fitted with high-efficiency filters or dust collection systems, will produce considerable dust which has to be controlled and the use of open flame methods to remove paint, such as LPG or blow torches, will produce lead fume, a hazard to the operator. Neither of these methods is recommended unless strict safety measures are taken.
Preparation for repainting or overcoating requires roughening the surface and removing flaking paint. This involves the use of sandpaper or scrapers, both of which produce paint debris. A good alternative is to use a scraper with a tungsten blade (eg, Linbide), which will remove the paint in large particles which are more easily managed. If sanding by hand, wet sanding will help reduce dust. This involves simply dipping the sanding block and sandpaper in a bucket of water before sanding or spraying the surface with water before sanding. A ground sheet will still need to be used to collect pooled or dripped water containing lead dust.
The following are the measures to be taken. Some of these measures may not be necessary when removing small areas of paint or preparing a surface for recoating.
- Use a ground sheet large enough to contain all the paint debris generated. If working on a scaffold, tie a sheet underneath to catch falling paint debris. The sheet should be clean (ie, not contain lead contamination from previous lead-based paint removal). Disposable polythene sheeting is recommended.
Note: Disposable polythene sheeting is recommended in preference to reusable dust sheets because of the tendency not to clean dust sheets, which may lead to cross-contamination. It has been suggested that polythene sheeting may increase the fire hazard but this problem is not evident in the United States, where polythene sheeting is extensively used in paint removal operations. - Work in such a way as to minimise dust and fume generation and the transfer of debris away from the immediate work area. Avoid working when wind or draughts could cause debris to be blown away from the work area containment or inside the building.
- Wear a filter respirator appropriate for the airborne contaminants produced. A toxic dust respirator is required for abrasive removal work, but this will not protect against fumes where lead-based paintwork is heated, or where solvents are used. Guidance in the purchase, use and maintenance of filter respirators is provided in AS/NZS 1715:1994 Selection, use and maintenance of respiratory protective devices. A free publication, A Guide to Respirators and Breathing Apparatus is available from any Department of Labour office.
- Remove accumulated dust as often as is necessary to prevent it spreading from the immediate work area. As a minimum, do this on a daily basis where practicable, using a vacuum cleaner fitted with a high-efficiency particulate air (HEPA) filter for dust and particulate removal. HEPA filters are capable of filtering out 99.97 percent of particles of 0.3 μm diameter or larger. The filter on a standard domestic vacuum cleaner is not capable of doing this.
Note: Vacuum cleaners that operate in 'wet' conditions will generally be safer to use than a 'dry' cleaner. Make sure the exhaust from the vacuum cleaner is positioned to prevent the disturbance of material in its path. - After vacuum removal, there are still likely to be dust traces remaining. Remove these by wiping surfaces with a damp cloth, and disposing of it after use. It is important to use a detergent in the water as this improves cleaning efficiency. Most common laundry powders which contain tri-sodium phosphate detergents are suitable for this purpose.
- Place lead-based paint debris and contaminated cloths directly into polythene bags and seal them prior to disposal.
- Small amounts of paint debris can be disposed of in the household refuse collection, or directly to the rubbish tip. For larger quantities, or if in doubt, check with the local city or district council. It may be necessary to arrange disposal at a controlled landfill.
- Never burn or bury lead-based paint debris or lead-based painted wood or use the timber for firewood as this may cause further hazards or spread the contamination.
6.4 Surface coating
- Select an appropriate surface preparation method (see Tables 1 and 2).
- Select an appropriate coating, given the condition of the surface to be covered and the likely use of the property.
- Select necessary personal protective clothing and equipment (see Tables 1 and2).
- Prepare the surface to accept the coating. This is essentially a cleaning and buffing process, but also requires the removal of all loose substrate and grease from the surface, as this will reduce adhesion of the new coating.
- Apply the coating.
6.5 Special precautions for interior paintwork
Preparation
- 1Seal windows, doors, ventilators and other openings as necessary to ensure that dust generated does not leave the room. Adhesive tape should suffice.
- Remove all soft furnishings (including curtains and carpets where practicable) from rooms to be treated. Cover furnishings which cannot be removed with polythene sheeting, and seal it to prevent dust entering the fabric.
- Remove other furniture from the room as necessary before beginning the job.
- Remove all food and medicines which cannot be put in sealed cupboards or containers.
- Install polythene covers, taped down if necessary, to prevent paint fragments and dust from contaminating the carpets and remaining fittings. A polythene groundsheet beneath the work area is a minimum requirement.
Decontamination
- Remove accumulated dust as often as is necessary to prevent it spreading from the immediate work area. As a minimum, do this on a daily basis. Use a HEPA vacuum cleaner to remove dust traces from the work area and surroundings, and wet-mop the polythene dust sheets after removal of gross dust.
- When the surface preparation work is complete, wet-wipe the prepared surface and other affected surfaces with a disposable cloth to remove any dust traces. Wipe all shelves, walls and windows where dust may have settled. Dispose of the cloth along with the paint debris.
- If soft furnishings have been contaminated, clean them thoroughly before replacing. If grossly contaminated, there may be no option but to dispose of them.
6.6 Special precautions with exterior paintwork
Preparation
- Where contaminated dust may escape from the work area or enclosure, seal windows, doors, ventilators and other openings (including eaves) of the building and nearby buildings (or rooms), to prevent dust contamination entering occupied areas.
- Use a groundsheet to catch paint debris and prevent soil and vegetation being contaminated by lead.
- Where wind is likely to scatter or spread dust, it may be necessary to use a wet sanding or chemical stripping method instead of a 'dry' removal method, or delaying preparation until conditions are improved.
- If removing paint by water blasting, ensure the waste water goes through a filter or earth dam before passing into the stormwater drain or ground soakage. This will filter out the paint fragments, which should then be disposed of as a contaminated waste. For larger jobs, settlement and filtration of the waste water may be necessary prior to its disposal in the stormwater drain.
Note: The disposal of waste water in a stormwater drain would only be acceptable if there were no adverse effects on the environment. Normally it is not practicable to divert waste water to the foul sewer. In either case, lead in the waste water is likely to enter the environment. The emphasis should be on removal of lead contaminants at source and proper disposal of the concentrated contaminated waste.
Decontamination
- Remove accumulated dust as often as is necessary to prevent it spreading from the immediate work area. As a minimum, do this on a daily basis.
- Use a vacuum cleaner fitted with a HEPA filter for removing the remaining dust and particulates from the surrounding area. Dispose of the polythene sheeting or wash it down, collecting the residue for safe disposal.
- Remove the paint dust on ledges, windows and walls with a damp cloth, and dispose of this along with other paint debris.
- Where soil or vegetation is contaminated by paint dust or fragments, it may be necessary to remove and dispose of the affected layer. Contamination on concrete or other impermeable surfaces may be rinsed away with water but only if the wash water goes through an earth dam or filter into a drain. The earth and filtered material must be disposed of safely.
6.7 Protective clothing
- Wear a good-quality, properly fitted, toxic dust filter respirator when sanding, making dust, or burning off lead-based paint. If using a disposable type, only those with double head straps are suitable.
- Respirators must meet the requirements of the New Zealand/Australian Standard AS/NZS 1716-1994 Respiratory protective devices. A free publication, A Guide to Respirators and Breathing Apparatus, is available from all Department of Labour offices.
- Replace respirator filters as required and ensure that all protective equipment is cleaned and stored properly.
- Wear overalls and a hat (especially when dry-sanding) to prevent dust accumulation in clothing and hair. Disposable coveralls are recommended for dusty work. Do not wear contaminated overalls or boots home as this can spread lead contamination and put family members at risk.
- Wear boots and gloves. Clean boots at the site or leave boots at the site so that lead dust is not carried to the vehicle or home.
6.8 Personal hygiene
- Do not smoke while removing paint, as hand to mouth contact may increase the risk of eating or inhaling lead paint dust.
- Wash hands before eating, drinking or smoking. Do not eat or smoke in the work area.
- Place contaminated overalls in clean polythene bags before removing them from the work area, as they are a significant source of contamination to others.
- Non-disposable overalls should be changed twice weekly (or more frequently, if necessary) and laundered separately from other domestic clothing and linen. When laundering contaminated overalls, store them away from other clothes. Do not shake prior to laundering. Disposable overalls provide a simple and safe method of protection.
- Clean equipment thoroughly of dust and paint fragments before it leaves the work area. A vacuum clean followed by a wet-wipe is normally sufficient.
- Wash or wipe clean boots and gloves with a damp cloth at the end of each work day.
- Replace or change filters on respirators according to manufacturers' instructions or as circumstances dictate.
Figure 1: Indoor paint removal
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Figure 2: Outdoor paint removal
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Table 1: Manual paint removal methods
| Hand scraping/sanding | Chemical stripper | Heat treatment | |
|---|---|---|---|
| Options |
Dry sandpaper Wetted sandpaper may be used to suppress dust Rasp, wire brush, shave hook, scraper |
Solvent-based paint stripper Alkaline paint stripper Brush for application Scraper for treated paint removal |
Infra-red (recessed flame) Hot-air blower Electric paint stripper Blowtorch (direct flame) (not recommended due to release of lead fumes) |
| Hazards present |
Dust inhalation Dust ingestion from contaminated hands Cross-contamination from overalls Dust contamination of carpets, etc |
Solvent fume inhalation Skin irritation and eye burn Respiratory irritation Cross-contamination from overalls |
Skin and eye contamination Cross-contamination from overalls Fire hazard Fume inhalation from flame contact methods (>450oC) |
| Personal protective equipment |
Toxic-dust filter respirator Gloves Boiler suit Hat (covering hair) Safety goggles |
Toxic-dust filter respirator Organic vapour respirator if solvents used Safety goggles Gloves Boiler suit Hat (covering hair) Other precautions as per the Safety Data Sheet Fire extinguisher where flammable chemicals are used |
Lead-fume, dust and mist filter respirator Gloves Boiler suit Hat (covering hair) Safety glasses |
| Other safety measures |
Polythene dust sheet to collect debris Soft bristle brush to gather debris Wet-wipe treated and nearby surfaces |
Keep the work area well ventilated Polythene dust sheet to collect debris Soft bristle brush to gather debris Wet-wipe treated and nearby surfaces Beware of skin and inhalation hazard |
Keep the work area well ventilated Polythene dust sheet to collect debris Soft bristle brush to gather debris Wet-wipe treated and nearby surfaces Have a fire extinguisher available |
| Waste management |
Place paint debris in a sealed polythene bag marked 'lead-based paint debris' Dispose of contaminated wash water to sewer (see section 6.6.4) |
Place paint debris in a sealed polythene bag marked 'lead-based paint debris' Dispose of contaminated wash water to sewer (see section 6.6.4) |
Place paint debris in a sealed polythene bag marked 'lead-based paint debris' Dispose of contaminated wash water to sewer (see section 6.6.4) |
Table 2: Other paint removal methods
| Machine sanding | Water blasting | Abrasive blasting | |
|---|---|---|---|
| Application |
Only HEPA filter-fitted machines should be used particularly when sanding indoors All machines used outdoors should have dust collection systems |
Outdoor application only Must not be used for domestic paint removal as this method can spread paint chips and dust significant distances into the surrounding environment |
Must not be used for domestic paint removal or in other situations where people may be exposed |
| Options |
Orbital sander Disc or belt sander Disc grinder Flap wheel, wire brush or disc rasp (drill attachments) |
High-pressure water lance Steam generator with chemical dosing apparatus Compressor |
|
| Hazards present |
Dust inhalation Dust ingestion from contaminated hands Cross-contamination from overalls |
Dust ingestion from contaminated hands Cross-contamination from overalls |
|
| Personal protective equipment |
Toxic-dust filter respirator Disposable coverall Disposable boot covers Gloves Hat (covering hair) |
Waterproof gloves Barrier cream Water resistant boiler suit Hat (covering hair) |
|
| Other safety measures |
Others in the dust-affected area to wear toxic-dust filter respirators and overalls Polythene containment to prevent debris loss from the work area Daily dust removal by vacuum cleaner with HEPA filter Wet-wipe treated and nearby surfaces |
Polythene containment to prevent debris loss from the work area Daily debris removal by pressure hose Remove paint particles washed onto adjacent land Wet-wipe treated and nearby surfaces |
|
| Waste management |
Place paint debris in a sealed polythene bag marked 'lead-based paint debris' Dispose of contaminated wash water to sewer (see section 6.6.4) |
Place paint debris in a sealed polythene bag marked 'lead-based paint debris' Dispose of contaminated wash water to sewer (see section 6.6.4) |
