| 4-Nitrophenol is more toxic than 2-nitrophenol in animals. Rats exposed to 112 mg/m3 for 2 weeks develop methemoglobinemia. No effect after dust exposures of 30 mg/m3 for 3-6 hours/day, 5 days a week for 4 weeks[ATSDR ToxProfiles] Can be absorbed through intact skin[HSDB] A mild skin and eye irritantCan induce methemoglobinemia after ingestion[ICSC]The major hazards encountered in the use and handling of 2-nitrophenol stem from its toxicologic properties. Toxic by all routes (ie, inhalation, ingestion, dermal absorption), exposure to this light yellow, crystalline substance, may occur from its use as a chemical intermediate. Effects from exposure may include burns to the skin and eyes, headache, dizziness, shock, unconsciousness, and death from cardiac or pulmonary failure. Contact with 2-nitrophenol should be controlled by local exhaust ventilation at the point of contaminant generation. Where this is not possible, contact should be prevented by wearing full protective clothing, including rubber gloves, and an organic vapor canister respirator, or in emergency situations, a self-contained breathing apparatus. If contact does occur, immediately flush affected skin or eyes with running water for at least 15 minutes, and remove and isolate contaminated clothing at the site. While 2-nitrophenol does not ignite easily, it can burn, emitting toxic oxides of nitrogen. Also, containers may explode in the heat of a fire. For small fires involving 2-nitrophenol, extinguish with dry chemical, CO2, Halon, water spray, or standard foam, and for large fires, use water spray, fog, or standard foam. Runoff from fire control water may give off poisonous gases or cause pollution, and should be controlled by diking, as necessary. 2-Nitrophenol should be stored away from sparks, flames, or other sources of ignition. Small spills of 2-nitrophenol may be taken up (if liquid, with sand or other noncombustible absorbent) and placed into containers for later disposal. Large spills should be contained in pits, or other holding areas that are sealed with an impermeable flexible membrane liner. Solids should be covered with a plastic sheet. Liquids should be neutralized with slaked lime, crushed limestone, or sodium bicarbonate, and diked, if necessary, to prevent runoff from entering water sources or sewers. Spills of 2-nitrophenol in water may need to be trapped at the bottom with sand bag barriers, activated charcoal applied, and the trapped material removed with suction hoses, mechanical dredges, or lifts. Prior to implementing permanent land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance. |
