General Industry Chemicals & Toxic Substances

A work environment that poses an immediate threat to an employee's life and health is referred to as immediately dangerous to life and health (IDLH).

Respirable particles are dust, fibers, fumes, and other particles that can go past the nose and mouth and enter deep into the respiratory system. These particles are less than 10 microns (µm) in diameter. A micron is 1 millionth of a meter (1/96,000 of an inch). Toxic fumes, dusts, mists, and other particles that are less than 10 microns in diameter are invisible. Examples of respirable particles include:

• Silica
• Lead
• Arsenic
• Ammonia
• Hexavalent chromium

Toxicity is represented by the median lethal dose, which is the concentration of a material that causes death in 50 percent of a group of test animals.

To learn more about Industrial Chemical Hazards visit our Industrial Chemical Hazards & Toxic Substances Online Training web page.