Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Classes of sampled exposure groups in relationship to silica exposures
| Class A | Class B | Class C |
|---|---|---|
| Jumbo operators | Blastmen | Supervisors |
| Cubex operators | Service men | Truck operators |
| Solo operators | Diamond operators | Bogger operators |
| Shotcrete operators |
