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Carcinogen

By , About.com Guide

Updated October 22, 2007

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Definition:

A carcinogen is defined as any substance that can cause or aggravate cancer.

The International Agency for Research on Cancer assigns carcinogens a rating by grouping them into one the following five standard classifications:
  • Group 1: The agent is carcinogenic to humans.
  • Group 2A: The agent is probably carcinogenic to humans.
  • Group 2B: The agent is possibly carcinogenic to humans.
  • Group 3: The agent is not classifiable as to its carcinogenicity to humans.
  • Group 4: The agent is probably not carcinogenic to humans.
See also: Cancer

Sources:

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