A laboratory evaluation of wipe testing based on lead oxide surface contamination

Area of Science:

• Industrial Hygiene
• Environmental Science
• Analytical Chemistry

Background:

• Wipe testing is a common method for assessing surface contamination in industrial settings.
• Limited scientific validation exists for wipe testing procedures regarding accuracy and reproducibility.
• Existing methods, including the Occupational Safety and Health Administration (OSHA) procedure, may have deficiencies.

Purpose of the Study:

• To quantitatively evaluate the effectiveness and repeatability of various wipe testing methods.
• To identify optimal wipe materials and techniques for different surface types (porous and non-porous).
• To improve the reliability of surface contamination measurements for health hazard assessments.

Main Methods:

• A laboratory evaluation using lead oxide dust as a model contaminant.
• Development of a dust dispersion system for controlled surface contamination.
• Testing of diverse wipe materials: moistened filter paper, paper towels, adhesive labels, and tape.
• Analysis of recovery rates and repeatability based on surface type, material, and operational variables.

Main Results:

• Moistened filter paper achieved up to 90% quantitative recovery with good repeatability on non-porous surfaces.
• Adhesive sampling materials, applied with maximum pressure, yielded an optimal 77% recovery on porous surfaces.
• Recovery rates were significantly influenced by surface porosity, wipe material, and application pressure.

Conclusions:

• Wipe testing methodology can be significantly improved for accurate surface contamination assessment.
• Optimized methods, particularly using moist paper for non-porous and adhesive materials for porous surfaces, enhance lead dust detection.
• Reliable surface contamination data is crucial for mitigating occupational health risks.