Something is still killing sandblasters. It is a lung disease called silicosis, and it is preventable. The disease and its cause have been recognized for decades; yet many sandblasters still contract this debilitating and deadly disease caused by the inhalation of silica sand dust.
Because controlling a sandblaster's exposure to silica dust is apparently so difficult, one way of reducing the risk of silicosis to this segment of the work population is by substituting a less toxic material for silica sand during abrasive blasting operations.
Great Britain and the European Economic Community have restricted the use of silica sand as an abrasive blasting material since 1949, and 1966, respectively. The National Institute of Occupational Safety and Health (NIOSH) has recommended since 1974 that silica sand (or other substances containing more than one percent free silica) be prohibited as an abrasive blasting material and that less hazardous substitutes be used.
There are a number of materials available as alternative abrasive blasting media. The major substitute materials are listed inside this bulletin along with some information about each. Additional information regarding particular applications should be obtained from the distributors of the various substitute materials.
Note that the cost per ton is misleading when compared to silica sand because many of the listed substitutes are recyclable and can therefore be reused. A more useful index of actual cost is price per square foot. A formula used in the industry to calculate the cost per square foot is presented on the last page of this bulletin. The real cost will vary depending on the particular application and factors associated with each job. When compared to silica sand in this manner, you will find that the costs of some silica substitutes are competitive.
The health effects of many of the silica substitutes have not been determined, and the materials removed by abrasive blasting are often very hazardous. It is therefore important to remember that no matter what abrasive blasting material you use, you must still employ appropriate control measures (e.g. containment, ventilation, and filtration) as well as provide workers with training and effective personal protective equipment (e.g. respirators and clothing).
New Jersey State Department of Health
Occupational Health Service
Occupational Health Surveillance Program
PO Box 360, Trenton, N.J. 08625-0360
(609) 984-1863
| PRICE* | SPECIAL EQUIPMENT | PROPERTIES | |
| ALUMINUM OXIDE | $660/Ton | None Required (Usually Used in Cabinets or Rooms with Recycling Equipment |
Closely Sized Very Hard (MOH 8.5-9) |
| BAKING SODA (Sodium Bicarbonate) |
$900/Ton | Yes (Meters Less Product/Min and Dries Air) |
Natural (Flow and Rinse Agents Added) Water Soluble Non-Sparking Non-Flammable |
| COAL SLAG | $44/Ton | None Required | Hard (MOH 6-7) Angular Uniform Density Low Friability |
| COPPER SLAG | $50/Ton | None Required | Hard (MOH 7-8) Blocky Sharp Edged |
| CORN COB GRANULES | $350/Ton | Special Ventilation May Be Required in Enclosed Areas to Control Combustion |
Medium Hardness (MOH 4.5) Non-Sparking |
| DRY ICE (Carbon Dioxide) |
$60-80/Ton | Dry Air Required | Natural Gas in Solid State |
| GARNET | $325/Ton | None Required (Additional components required in order to recycle Media) |
Very Hard (MOH 8) Very Heavy (S.G. 4.1) Subangular |
| GLASS BEADS | $500/Ton | None Required (Usually Used in Blast Cabinets with Recycling Equipment) |
Manufactured of Soda Lime Glass |
| NICKEL SLAG | $70/Ton | None Required | Very Hard (MOH 7-8) Blocky Sharp Edged |
| NUT SHELLS | $360/Ton | Special Ventilation May Be Required in Enclosed Areas to Control Combustion | Soft Non-Sparking |
| OLIVINE | $76/Ton | None Required | Natural Mineral Hard (MOH 6.5-7) High Specific Gravity, Angular |
| PLASTIC MEDIA | $3000-4000/Ton | None Required (Additional Components Required in Order to Recycle Media) |
Soft Non-Abrasive Polyester, Urea, Melamine Varieties |
| STAUROLITE | $75-140/Ton | None Required (Additional Components Required in Order to Recycle Media) |
Rounded Grains Hard (MOH 6.5-7) Irregular Shape |
| STEEL GRIT & SHOT | $425-475/Ton | None Required (Additional Components Required in Order to Recycle Media) |
Uniform Size Uniform Hardness Can be Manufactured to Various Specifications |
Silica Substitutes continued ...
| ADVANTAGES | ||
| ALUMINUM OXIDE | Cleaning Hard Metals (e.g. Titanium) Removing Metal Etch Glass Carve Granite |
Recyclable |
| BAKING SODA (Sodium Bicarbonate) |
General Paint Removal Stripping Aircraft Skins Cleaning Surfaces in Food Processing Plants Removing Paint from Glass |
Less Material Used/Less Cleanup Low Nozzle Pressures (35-90 PSI) Non-Sparking Water Soluble |
| COAL SLAG | General Paint, Rust & Scale Removal from Steel Paint Removal from Wood Exposure of Aggregates |
Less Than 1% Free Silica Inert Fast Cutting Creates Anchor Profile |
| COPPER SLAG | General Paint, Rust & Scale Removal from Steel Paint Removal from Wood |
Rapid Cutting |
| CORN COB GRANULES | Deburring Paint & Rust Removal from Wood & Metal |
Low Consumption Low Dust Levels Biodegradable |
| DRY ICE (Carbon Dioxide) |
Cleaning Aircraft Parts Cleaning Exotic Metals |
No Residue Remains Minimal Cleanup |
| GARNET | General Paint, Rust & Scale Removal from Steel | Lower Nozzle Pressures (60-70 PSI) Low Dust Levels Fast Cleaning Rates Can be Recycled 6-7 Times Low Free Silica |
| GLASS BEADS | Cleaning & Polishing Deburring |
Uniform Size and Shape Recyclable Provide High Luster Polished Surface |
| NICKEL SLAG | General Paint, Rust & Scale Removal from Steel | Rapid Cutting |
| NUT SHELLS | Cleaning Soft Materials (e.g. Aluminum, Plastic, Wood) Cleaning Surfaces in the Petroleum Industry |
High Removal Speed Non-Sparking Low Consumption |
| OLIVINE | Clean Light Mill Scale & Rust from Steel 2.5 MIL Profile & Finer |
Low Chloride Ion Level Low Conductivity |
| PLASTIC MEDIA | Cleaning Soft Metals & Composites Cleaning Metal Fabric Screens |
Inert Recyclable Does Not Damage Metal Surfaces Low Nozzle Pressures (20-40 PSI) |
| STAUROLITE | Cleaning Corroded, Pitted, Weathered Steel Creating Anchor Profile on New Steel | Lack of Imbedment Good Feathering Low Dust Levels Recyclable 3-4 Times |
| STEEL GRIT & SHOT | Paint, Rust & Scale Removal from Steel Surface Preparation of Structural Steel in Centrifugal Wheel Units | Can be Recycled 100-200 Times Low Dust Levels Superior Visibility Portable Blast Rooms Available Creates Anchor Profile |
Silica Substitutes continued ...
| LIMITATIONS | |
| ALUMINUM OXIDE | Must be Reclaimed and Reused for Economy |
| BAKING SODA (Sodium Bicarbonate) |
May Damage Soft Brick |
| COAL SLAG | Tendency to Imbed in Mild Steel May Contain Toxic Metals |
| COPPER SLAG | Tendency to Imbed in Mild Steel May Contain Toxic Metals |
| CORN COB GRANULES | Does Not Create an Anchor Profile |
| DRY ICE (Carbon Dioxide) |
|
| GARNET | |
| GLASS BEADS | Does Not Create an Anchor Profile |
| NICKEL SLAG | Tendency to Imbed in Mild Steel, Poor Visibility, Might React with Corrosion Inhibitors Used in Wet Blasting May Contain Toxic Metals |
| NUT SHELLS | Non-Etching Potential Fire Hazard |
| OLIVINE | |
| PLASTIC MEDIA | Anchor Profile Limited to Soft Substrates (e.g. Aluminum and Plastic) |
| STAUROLITE | May Contain Up to 5% Free Silica |
| STEEL GRIT & SHOT |
Prices are only NJDOH estimates based on the best information available in 1994.
A formula for calculating the cost of abrasive blasting per square foot of surface area:
| ( | (A*B) + C + D | ) + E = Actual Cost | |||
| X | |||||
| where: | |||||
| A = | delivered cost of abrasive media | ( | $ | ) | |
| TON | |||||
| B = | consumption rate | ( | TONS | ) | |
| HOUR | |||||
| C = | labor cost | ( | $ | ) | |
| HOUR | |||||
| D = | equipment cost | ( | $ | ) | |
| HOUR | |||||
| E = | productivity | ( | SQUARE FEET | ) | |
| HOUR | |||||
| F = | miscellaneous(e.g. disposal costs) | ( | $ | ) | |
| SQUARE FOOT | |||||
