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Level 2: Substitution

Replace with Less Hazardous Alternative​

Substitution means replacing a hazardous substance, process, or equipment with something less hazardous.

If hazard cannot be eliminated, reduce it.

Why Substitution is Effective​

Advantages:

  • Reduces hazard at the source
  • Doesn't rely on worker behavior
  • Often permanent solution
  • May improve process efficiency

Limitation:

  • Doesn't completely eliminate risk (unlike Level 1)
  • Substitute may have different (though lesser) hazards

When to Consider Substitution​

Before purchasing:

  • Specify less hazardous alternatives
  • Compare products for safety

Reviewing existing materials:

  • Can current materials be replaced?
  • Are safer alternatives now available?

After incidents:

  • Was the hazardous material necessary?
  • Could safer alternative prevent recurrence?

Types of Substitution​

Chemical Substitution​

Replace hazardous chemical with less hazardous alternative:

Flammability:

  • Water-based paints/coatings instead of solvent-based
  • Aqueous cleaning solutions instead of petroleum solvents
  • Water-based adhesives instead of solvent-based

Toxicity:

  • Low-VOC or zero-VOC products
  • Non-toxic rust removers instead of acidic products
  • Lead-free paints

Carcinogenicity:

  • Non-asbestos materials (already mandated)
  • Silica-free abrasives for blasting
  • Alternatives to formaldehyde-releasing products

Construction Example: Substitute water-based concrete curing compound for solvent-based. Reduces flammability risk, vapor inhalation, and environmental impact while achieving same result.

Material Substitution​

Replace hazardous material with safer material:

Dust Generation:

  • Pre-mixed materials instead of powder (less dust when opening/using)
  • Paste/gel forms instead of powders
  • Pelletized materials instead of dusty granules

Weight:

  • Lightweight blocks instead of dense concrete blocks (manual handling)
  • Aluminum instead of steel (where strength permits)
  • Composite materials instead of solid timber (less weight)

Toxicity:

  • Treated timber with less toxic preservatives
  • Non-toxic insulation materials

Construction Example: Use lightweight hebel blocks instead of dense concrete blocks. Reduces manual handling strain (12kg vs 20kg) while providing same structural performance.

Equipment/Plant Substitution​

Replace with safer equipment:

Noise:

  • Electric tools instead of pneumatic (quieter)
  • Low-noise equipment models
  • Hydraulic instead of diesel-powered

Vibration:

  • Anti-vibration tools
  • Low-vibration equipment models

Safety Features:

  • Equipment with better guarding
  • Plant with operator protection (ROPS, FOPS)
  • Equipment with automatic safety features

Construction Example: Use electric-powered concrete saw instead of petrol-powered. Quieter (90dB vs 110dB), no exhaust fumes, lower vibration, easier to start.

Process Substitution​

Change how work is done to reduce hazards:

Manual to Mechanical:

  • Mechanical fastening instead of welding (eliminates fumes, fire risk)
  • Mechanical couplings instead of flange bolting (less manual handling)

Wet Instead of Dry:

  • Wet concrete cutting instead of dry (reduces silica dust)
  • Wet grinding/demolition (suppresses dust)

Different Technique:

  • Bolted connections instead of welded (easier to dismantle, no hot work)
  • Spray application instead of brush/roller (faster, less repetitive motion)

Construction Example: Use mechanical rock splitters instead of jackhammers for demolition. Quieter, less vibration, no dust, easier on operator.

Assessing Substitutes​

Don't Create New Hazards​

Ensure substitute is actually safer:

  • Check Safety Data Sheet (SDS) for chemical substitutes
  • Compare hazards (both must be considered)
  • Consider lifecycle impacts

Example of Poor Substitution: Replacing flammable solvent with toxic (but non-flammable) chemical. Reduced one hazard but introduced another - may not be improvement.

Verify Performance​

Substitute must do the job:

  • Achieves required outcome
  • Meets specifications
  • Compatible with materials/process

Example: Water-based paint must provide same protection, adhesion, durability as solvent-based paint it replaces.

Consider Practicality​

Will it work in practice?

  • Application method compatible with workflow
  • Available from suppliers
  • Workers trained in use
  • Cost reasonable

Trial and Evaluate​

Before full implementation:

  • Test substitute on small scale
  • Evaluate effectiveness
  • Get worker feedback
  • Monitor for unexpected issues

Practical Construction Examples​

Example 1: Concrete Release Agent​

Original: Solvent-based release oil

Hazards:

  • Flammable (flash point 40°C)
  • Harmful vapors
  • Skin irritant
  • Environmental impact

Substitute: Water-based release agent

Advantages:

  • Non-flammable
  • Low VOC
  • Minimal odor
  • Easier cleanup
  • Safer for environment

Result: Eliminated flammability risk, reduced vapor exposure, improved worker acceptance. Same concrete finish quality.

Example 2: Abrasive Blasting Media​

Original: Silica sand for blasting

Hazards:

  • Respirable crystalline silica (causes silicosis)
  • Serious long-term health effects

Substitute: Non-silica abrasives (garnet, steel grit, glass beads, crushed walnut shells)

Advantages:

  • Eliminates silica exposure
  • May be recyclable (garnet, steel grit)
  • Effective surface preparation

Considerations:

  • Different media for different applications
  • Cost may be higher
  • May require equipment adjustment

Result: Silica exposure eliminated, same surface preparation achieved.

Example 3: Cleaning Product​

Original: Hydrochloric acid for concrete cleaning

Hazards:

  • Corrosive (burns skin, eyes)
  • Toxic fumes
  • Requires PPE, specialized disposal

Substitute: Phosphoric acid-based cleaner or enzymatic cleaner

Advantages:

  • Less corrosive
  • Safer to handle
  • Reduced PPE requirements
  • Easier disposal

Verification: Trial showed effective cleaning with longer application time (acceptable trade-off).

Result: Reduced corrosion hazard, safer for workers, same cleaning result with minor process adjustment.

When Substitution Not Sufficient​

If substitution reduces but doesn't adequately control the risk, additional controls required:

Add Level 2 Engineering Controls:

Add Level 3 Controls:

Example: Substituting water-based paint for solvent-based reduces flammability and vapor exposure but may still require ventilation (engineering control) and gloves (PPE) for skin protection.

Information Sources​

Finding Safer Alternatives:

  • Safety Data Sheets (compare hazard sections)
  • Supplier technical information
  • Industry associations
  • SafeWork Australia guidance materials
  • Similar industries (may have already found solutions)

Chemical Substitution:

  • Australian Government ChemAlert database
  • International Chemical Toolkit (ILO)
  • Supplier recommendations

Consultation​

Involve workers when considering substitution:

  • They know practical issues with current materials
  • Can trial alternatives and provide feedback
  • More likely to accept change if involved

Example: Workers trialing new cleaning product can report on effectiveness, ease of use, any issues - ensuring substitute actually works in practice.

Summary​

Substitution:

  • Replace hazardous with less hazardous
  • Reduces risk at source
  • Permanent solution
  • Must verify substitute is actually safer and performs adequately

Key Principle: If you can't eliminate the hazard (Level 1), reduce it through substitution before accepting lower-level controls.