Exposure to Silica in Pipe Laying

1
(No Transcript)
2
Case Study Silica Exposure from Cutting Concrete
PipeWisconsin Council of SafetyWisconsin Dells,
WIApril 30, 2008

• Matthew A. Stein MS, CIH
• Compliance Safety Health Officer
• Eau Claire, WI 54701
• 715-832-9019

3
Initial Complaint

• Report of Employee Slipping and Falling into
  trench where storm sewer was being placed
• Arrived on site and saw this. . .

4
(No Transcript)
5
Silica SEP

• OSHA has had Special Emphasis Program (SEP) for
  silica
• When we see a cloud of dust on a site we must
  find out how bad it is
• We asked the foreman when they would be cutting
  pipe next

6
Respiratory Protection On Site

• Respirator was used by employee in first picture
• Employee-owned equipment

7
Respiratory Protection On Site

• Other employees wearing disposable dust masks
  rated N95
• Assigned Protection factor (APF) 10
• Required by employer when cutting
• Employer did not have respiratory protection
  program for construction personnel

8
Air Sampling Equipment

• Personal Air Pump with Cyclone

9
Sampling Set up
10
Operation

• Used diamond tip saw with water spray
• Cutting took 24 minutes incl. time to turn pipe

11
Results

• Pipe contained 15 silica
• 2.5 mg of dust generated in 24 minutes
• Employee exposed to approx. 5.5 times the 8-hour
  allowable limit for silica
• If employee were cutting for 8 hours would be 104
  times daily allowable limit

12
Conclusions

• Respiratory Prot. Plan Hazard Assess.
• Employer made pipe at different part of business
• RPP did not cover pipe laying crews
• Employee supplied respirator was inadequate
• Employer had not sampled operation

13
Conclusions

• Cutting wet was not enough
• Inadequate pressure or volume
• Cutting too fast
• Too much dust
• Work may have been sited poorly

14
Conclusions

• Dust mask may have been enough IF
• Dust control was better
• Short time cutting approx. 45-50 minutes/day
• Respiratory protection program covered
  construction employees cutting sewer pipe

15
Next Steps

• Implement full respiratory protection plan for
  pipe layers who cut storm sewer
• Upgrade to better respirators PAPR 25 -1000x
  protection (see APFs 29 CFR 1910.134(d)(3)(i)(A))

16

• Questions?
• Thank You

17
Disclaimer

• This information has been developed by an OSHA
  Compliance Assistance Specialist and is intended
  to assist employers, workers, and others as they
  strive to improve workplace health and safety.
  While we attempt to thoroughly address specific
  topics or hazards, it is not possible to include
  discussion of everything necessary to ensure a
  healthy and safe working environment in a
  presentation of this nature. Thus, this
  information must be understood as a tool for
  addressing workplace hazards, rather than an
  exhaustive statement of an employers legal
  obligations, which are defined by statute,
  regulations, and standards. Likewise, to the
  extent that this information references practices
  or procedures that may enhance health or safety,
  but which are not required by a statute,
  regulation, or standard, it cannot, and does not,
  create additional legal obligations. Finally,
  over time, OSHA may modify rules and
  interpretations in light of new technology,
  information, or circumstances to keep apprised
  of such developments, or to review information on
  a wide range of occupational safety and health
  topics, you can visit OSHAs website at
  www.osha.gov.