5-Nitro-o-toluidine (2-Methyl-5-nitroaniline)

Manufactured as an intermediate for azo dyes/pigments and other industrial products; can enter air, dust, and wastewater during production, handling, or spills [1][2].

Breathing dust/fumes at work; skin contact with powders or contaminated surfaces; swallowing small amounts from hand-to-mouth or contaminated water/soil near facilities; rarely from breakdown of certain dyes [1][2].

Short-term exposure can irritate eyes/skin and cause methemoglobinemia (reduced blood oxygen; symptoms include headache, dizziness, blue-tinged skin). Repeated exposure may affect the liver and blood. It is also toxic to aquatic life, so spills threaten waterways [2][3].

Dye/pigment and lab workers; maintenance/cleanup crews; people near poorly controlled industrial sites; infants and people with G6PD deficiency are more sensitive to methemoglobinemia [2].

At work, use closed systems, local exhaust, chemical-resistant gloves/clothing, and wash before eating. Contain powders; clean with wet methods/HEPA. At home, avoid tracking workplace dust; follow local water advisories; store/dispose per label/SDS [1][3].