Chemical-protective clothing (CPC) is designed to safeguard workers from hazardous chemical exposure. It is manufactured in a variety of materials, each offering different levels of resistance and protection against specific chemicals.
Selecting the appropriate CPC material depends on the chemicals present, their concentration and form (liquid, gas, vapor, solid), and the tasks to be performed. The ideal material provides maximum resistance to permeation, degradation, and penetration.
Key Terms and Definitions
- Permeation
The process by which a chemical dissolves in and/or moves through a protective clothing material on a molecular level. Even materials that appear intact may allow chemical molecules to pass through over time. - Degradation
The loss or alteration of a fabric’s chemical resistance or physical properties due to exposure to hazardous substances, repeated use, or environmental factors such as sunlight, temperature, or humidity. Degraded materials may become brittle, discolored, or swollen. - Penetration
The movement of chemicals through imperfections in the clothing such as zippers, stitched seams, or pinholes. Penetration can occur when a chemical bypasses the material rather than passing through it.
Selection Considerations
Choosing chemical-protective clothing is a complex and critical process that must be carried out by trained and qualified personnel. Selection occurs during the site characterization phase and depends on:
- The type and concentration of hazardous substances present
- The physical state of contaminants (solid, liquid, or gas)
- Task duration and level of worker activity
- Environmental conditions such as temperature, humidity, and wind
- Compatibility with other personal protective equipment (e.g., respirators)
Best Practices for CPC Selection
- Evaluate the performance characteristics of the clothing against site-specific requirements.
- Whenever possible, inspect representative garments prior to purchase.
- Consult experienced personnel or manufacturers regarding performance and suitability.
- Ensure all protective clothing is properly fitted, maintained, and replaced when compromised.
- Employers are ultimately responsible for verifying that all PPE, including CPC, meets applicable safety standards and provides adequate protection for the task.