About – ortho-Toluidine

chemical structure for ortho-Toluidine

About o-Toluidine

Below is some information about o-toluidine and the health problems it may cause. This information may be helpful to determine whether you are or have been exposed to o-toluidine in your job or whether symptoms you’ve experienced could be related to o-toluidine exposure.

What it looks like

  • At room temperature, it is a thick, light yellow liquid
  • When exposed to air and light, it will darken to reddish/orange brown

What it smells like

  • It has a fishy odor
  • It has a low odor threshold, which means most people will smell it even at very low levels.

How you can be exposed

  • Breathing it in
  • Getting it on your skin

Who is most likely exposed

  • Industrial workers who use it

Beyond the industrial setting, there is little information available about o-toluidine exposure among other workers and the general public. We know that others may also be exposed, but probably at lower levels, including:

  • Hair stylists because o-toluidine is used in some hair dyes.
  • Laboratory workers who use o-toluidine to stain tissues or as part of a reagent to analyze glucose.
  • The general public because o-toluidine is in
    • cigarette smoke
    • certain hair dyes
    • Prilocaineexternal icon, a cream that is applied to the skin to numb it for minor dental and surgical procedures and blood draws. Our bodies convert Prilocaine to o-toluidine after it is absorbed.
    • air, soil, or water contaminated with o-toluidine

Health problems it may cause

Short-term effects

  • skin, eye, and respiratory irritation
  • cyanosisexternal icon from a decrease in the supply of oxygen to the body due to methemoglobinemiaexternal icon. This condition occurs when o-toluidine changes hemoglobin, which carries oxygen in the blood, to methemoglobin, which hinders the release of oxygen.
  • central nervous system depression including dizziness, headache, and confusion

Long-term effects

If you are an industrial worker who works with o-toluidine, learn how to keep yourself and your family safe.

Page last reviewed: June 6, 2014