CSLB C-33 Painting & DecoratingSafetyMedium

A painting contractor is assessing a project involving the removal of existing paint from a concrete floor using a floor grinder. Airborne dust is a significant concern. What is the most effective type of respiratory protection required for workers operating this equipment, assuming lead or silica are NOT present?

  1. ADust mask (non-NIOSH approved)
  2. BSurgical mask
  3. CHalf-mask air-purifying respirator with P100 filters
  4. DN95 filtering facepiece respirator
Show answer & explanation

Correct answer: C. Half-mask air-purifying respirator with P100 filters

Floor grinding generates large amounts of fine particulate dust. A half-mask air-purifying respirator with P100 filters provides a high level of protection against all oil and non-oil-based particulates, offering superior filtration compared to N95s for such demanding tasks, even when lead or silica are not explicitly identified.

Why the other options are wrong

  • A. Non-NIOSH approved dust masks offer minimal protection and are not considered adequate respiratory protection for hazardous dusts.
  • B. Surgical masks are designed for splash protection and to contain exhaled particles, not to protect the wearer from inhaling fine dust.
  • D. An N95 provides protection against 95% of non-oil particulates, but a P100 offers 99.97% protection and is more appropriate for high-dust generating activities like grinding.

Particulate Respirator Filtration

The efficiency of a respirator's filter in removing airborne particulate matter, commonly rated by NIOSH (e.g., N95, P100).

  • N-series for non-oil particulates.
  • P-series for oil and non-oil particulates.
  • 100 rating means 99.97% filtration efficiency.

Memory trick: P100 for heavy dust, a must for your lungs to trust.

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