This document summarizes an organization's approach to managing respirable silica dust hazards on construction sites. It found high exposures to silica dust that exceeded occupational exposure limits from tasks like cutting fiber cement boards and concrete. It implemented an approach with multiple components, including identifying risks, exposure monitoring, training workers, implementing engineering controls like dust extraction tools, administrative controls like safe work practices, personal protective equipment, and health surveillance. This comprehensive strategy successfully cleared the air of hazardous silica dust on its construction sites.

1. ClearingtheAiron
ConstructionSites

2. OneApproachto
Managing RespirableHazards

3. A BetterApproach
• Focus on Occupational Health
• New Zealand Experience1
o 50 workplace deaths on average p.a.
o 600-800 died from work related
disease p.a.
o 16:1 ratio
• The UK Experience2
o 133 workplace deaths on average p.a.
o 13,000 died from work related disease*
o 99:1 ratio
• “Health, Like Safety”
1. Worksafe NZ 2015
2. HSE UK 2013/2014

4. Construction
Dust
• Asbestos has been the focus
• Treated timber dusts
• Nuisance dusts
• An emerging risk is
silica

5. • Crystalline silica is one of the most abundant materials on earth
• Found in different forms, quartz is the most common
• Quartz is found in almost all types of rock, sand, clay and gravel
Silicais Everywhere

6. “…sowhyissilicathe
hottopicon
constructionsites?”

7. Silicais a
major
component
of many
building
materials
Material Silica %
Sandstone >70%
Concrete 25 – 70%
Tile 30 – 45%
Bricks >30%
Fibre Cement
Board
10 – 30%
Mortar 25 – 70%
Plaster Board /
Filler
0.2%

8. • In it’s natural form silica is relatively harmless
• However, when machined with high energy tools, silica dust is
released into the air and becomes a respiratory hazard
• Cutting, drilling, grinding, polishing, sanding or even sweeping
with a broom can create airborne silica dust
WhentheHarmlessBecomesHazardous

9. • Inhalable particles are expelled by the body’s defences
• Smaller respirable particles travel deep into the lungs
• And can cause irreparable damage and chronic health effects
• Asthma… COPD… Silicosis… Lung Cancer
• Respirable crystalline silica classified as a carcinogen since 1997
InhalableandRespirableDusts

10. The most hazardous dusts are those that you can’t see
Don’tLetYourEyesDeceiveYou
Viewed under Tyndall lightingViewed under normal lighting

11. FletcherLiving’s
SilicaDustStrategy
1. Identify and assess the risks
2. Prevent and control the exposures
3. Monitor exposures against and below the WES
4. Initiate employee health surveillance
5. Review and improve controls

12. Understandingthe Exposures
Exposure Monitoring
• Exposure Monitoring
• Certified Occupational Hygienist
• All trades working with silica
• Nine different worker samples
• Compared against WES .2mg/m3
o 11% breached WES
o 33% breached proposed new WES
.025mg/m3
o Highest sample 15 x WES

13. • Fibre cement board cutting
• Block cutting
• Concrete grinding & cutting
• Tile cutting
Four
Problematic
Tasks

14. Understandingthe Practices
Contractor Knowledge & Practices Survey
• 38 Contractors working with silica
• 25% machined indoors
• Only 49% use engineering controls
• None using class H vacuums
• 72% claimed to use RPE (disputed)
• Almost all used P1 disposable – no fit test
• 45% warn nearby personnel
• 30% created an exclusion zone
• 42% updated hazard board or warned others
• 42% use disposable liners
• Poor personal hygiene practices
• No exposure monitoring or health surveillance

15. “Contractors,whothoughsuspicious
of silica,were inadequatelyinformed
orresourcedtokeepthemselvesor
theirworkerssafe”

16. Assessingthe Risk
Environment, Health & Safety Risk Matrix
Severity
Likelihood
Insignificant
No Injury
Minor
First Aid
Moderate
Medical
Treatment
Major
Serious
Injury
Catastrophic
Fatality
Almost
Certain
Medium
(8)
High
(13)
Very High
(20)
Very High
(23)
Very High
(25)
Likely
Low
(6)
Medium
(11)
High
(17)
Very High
(21)
Very High
(24)
Possible
Low
(4)
Medium
(9)
High
(12)
Very High
(18)
Very High
(22)
Unlikely
Low
(2)
Low
(L5)
Medium
(10)
High
(14)
Very High
(19
Rare
Low
(1)
Low
(3)
Low
(7)
High
(14)
High
(16)
• Exposure / Duration
o a known carcinogen
o very high short term, but
infrequent exposures
o over long construction careers
• Severity = Major
• Likelihood = Likely
• Risk = Very High 21
• Industry Knowledge = Extensive
knowledge of risk control particularly
engineering and RPE controls
• Controls = readily available and feasible
• Cost = quite manageable and not
disproportionate to the risk

17. • Hosted series of Senior Leadership team workshops to explore options
• Elimination options elusive because silica is so prevalent in materials
• Substitution options were available:
o Substituting cedar for fibre-cement claddings
o Increasing proportion of products requiring less cuts (brick / speed-wall)
o Now trialling new generation timber weatherboard claddings
EliminationandSubstitutionControls

18. Engineering Controls
• Mandatory on-tool extraction for dry cutting
• Water suppression for blocks, bricks & concrete
• Integrated solutions: tool, shroud, vacuum, hose
• Negotiated <50% equipment upgrade subsidies
• Partnered with Placemakers to offer deals
• Promoting Class H vacuums to comply with
Worksafe’s 99.96% linea filtration guideline
• Distributed 100s of free low dust blades
• Provided training on cleaning and maintenance
• Introduced a reward and recognition programme
for early adopters

19. AdministrativeControls– Training
• 152 carpenters linea handling and installation
• 290 workers national Respiratory Roadshow:
o Exposure monitoring results
o Health effects of silica
o How to use a “group of controls”
o How to select, use and maintain RPE
• Training was translated for foreign workers
• 170 workers free lung function tests
• Some referred for medical intervention
• Family of toolbox talks, FAQs and SWPs
• Ongoing coaching and support by Supervisors

20. AdministrativeControls–SiteManagement
• Machining only in well-ventilated, external areas
• Custom signage warning of silica dust hazards
• Exclusion zones around machining operations
• Ban dry sweeping – either vacuums or hoses
• Consider winds and warn persons nearby
• Update hazard board
• Promoted rotation of tasks
• Sealed liners to be used in vacuums
• Safe waste disposal methods
• Promoted personal hygiene:
o washing hands
o coveralls / changing out of dusty clothes
o washing dusty clothes separately
o not contaminating cars, homes or family

21. AdministrativeControls– Supervision
• Initial engagement and education
• Has translated to compliance and enforcement
• Coaching on dust management practices
• Non compliances are identified and tracked
• Mandatory ‘Stop Work’ until resolved
• Extraction and RPE are the common violations
• RPE violations peaked during the Respiratory
Roadshow and have started to tail off since
33%
30%
15%
7%
7%
4% 4%
All Violations
Extraction
RPE
Water Suppresion
Exclusion Zone
Interior Cutting
Signage
Wind Conditions
0
2
4
6
8
10
Jan Feb Mar Apr Aug Sep Oct
RPE Violations

22. AdministrativeControls– Auditing
• Supplement supervision with HO auditing
• Tablet / Smart phone auditing APP
• Audit tool focused on dust management controls
• Corrective actions tracked to close-out as a site KPI
• Further survey to assess changes in knowledge and
practice

23. AdministrativeControls– Monitoring
• Exposure Monitoring
o Formal programme
o Identified similar exposure groups
o Conducted five yearly
o Or new/changed equipment/process
o Aims:
1. To not exceed the WES
2. And to attain ‘factors of safety’
• Health Surveillance
o Formal annual programme
o Achieved >90% uptake in year one
o Funded initial surveillance for workers in
target populations
o Encourage Contractors continue
surveillance

24. PersonalProtectiveEquipment
• 290 workers Respiratory Roadshow
• RPE as a last line of defence
• Training on the correct selection, fitment,
storage, maintenance & replacement of RPE
• 48 workers volunteered to shave for fit test
• 170 workers qualitative fit test to NZS 1715
• Issued fit test cards
• Contractor access PPE at Fletcher prices
• NZ Safety ran a mobile RPE shop
• Set minimum RPE standards

25. WhatHasBeenAccomplished?
• Worker education and empowerment
• Ongoing elimination / substitution options
• Extensive engineering controls programme
• Integrated RPE programme
• 290 workers Respiratory Roadshow
• Formal exposure programme
• Formal health surveillance programme
• Supervisor’s effectively managing dust controls
• Tablet-based dust auditing tool
• Significantly cleared the air on site

26. GettingStarted?
1. Identify your respiratory hazards
2. Exposure monitoring programme
3. Assess the risks to worker health
4. Involve workers in the development of controls
5. Seek to prevent exposure by elimination and
substitution
6. Use engineering controls to keep the hazard
away from workers
7. Use administrative controls to limit the time or
numbers of people exposed
8. Establish RPE programme – fit testing, training
9. Train workers in how to use all equipment
10. Maintain and clean all equipment
11. Health surveillance programme

27. Doyoubreathe freely?