“The toxicity of a substance is its ability to cause harmful effects. These
effects can strike a single cell, a group of cells, an organ system, or the
entire body. A toxic effect may be visible damage, or a decrease in
performance or function measureable only by a test. All chemicals
can cause harm. When only a very large amount of the chemical can
cause damage, the chemical is considered to be relatively non-toxic.
When a small amount can be harmful, the chemical is considered toxic.

“The toxicity of a substance depends on three factors: its chemical structure,
the extent to which the substance is absorbed by the body, and the body’s
ability to detoxify the substance (change it into less toxic substances) and
eliminate it from the body.

“Are “toxic” and “hazardous” the same? “No. …”
http://www.dhs.ca.gov/ohb/HESIS/uts.htm?

California’s Occupational Health Branch (OHB)
http://www.dhs.ca.gov/ohb/Default.htm

• Atrazine-Induced Hermaphroditism at 0.1 PPB in American Frogs (Rana pipiens): Laboratory and Field Evidence Environmental Health Perspectives; Volume 111, Number 4;April 2003
  http://ehp.niehs.nih.gov/members/2003/5932/5932.html
• Hermaphrodite Frogs Caused By Popular Weed Killer?
  By Bijal P. Trivedi; National Geographic Today
  “April 16, 2002 Atrazine, a top selling weed killer in the United States and the world, has
  been found to dramatically affect the sexual development of male frogs, turning them
  into hermaphroditesãcreatures with both male and female organsãat concentrations
  30 times lower than those deemed safe by the U.S. Environmental Protection Agency (EPA). …”
  http://news.nationalgeographic.com/news/2002/04/0416_020416_TVfrog.html
• Minnesota Center for Environment Advocacy
  http://www.mncenter.org/p.asp?WebPage_ID=7
  • Popular Pesticide Faulted for Frogs’ Sexual Abnormalities
    6/18/2003 Jennifer Lee The New York Times Ý Scientists from the Environmental Protection Agency say there is “sufficient evidence” to conclude that the country’s most widely used pesticide, atrazine, causes sexual abnormality in frogs. http://www.mncenter.org/p.asp?WebPage_ID=24&Profile_ID=258
• Profile: Hopping Mad
  A frog biologist battles an agrichemical giant
  by Kerry Tremain; Sierra Club
  http://www.sierraclub.org/sierra/200407/profile.asp
• New Study Finds Very Low Levels of Exposure to Common Herbicide Causes
  Sex Reversal, Hermaphroditism in Frogs
  FOR IMMEDIATE RELEASE CONTACT: Brandon Adams (919-541-5466); 23 October 2002
  http://ehp.niehs.nih.gov/press/atrazine.html
• The Story of Syngenta & Tyrone Hayes at UC Berkeley: The Price of Research
  A Berkeley Scientist Says a Corporate Sponsor Tried to
  Bury his Unwelcome Findings and Then Buy His SilenceÝ
  By GOLDIE BLUMENSTYK / The Chronicle of Higher Education v.50, i.10, 31oct03
  http://www.mindfully.org/Pesticide/2003/Syngenta-Tyrone-Hayes31oct03.htm