Toxic organics are organic compounds that pose a threat to human health and the environment. These compounds are often man-made, and their toxicity stems from their chemical structure and properties. Many sources define and regulate them differently, focusing on specific lists or categories.
Types and Examples of Toxic Organics
Toxic organic compounds can be categorized in several ways, including:
- Base/Neutral Extractibles: Examples include benziline, hexachloroethane, naphthalene, fluorene, and pyrene. These are substances that can be extracted from a sample using a basic or neutral solvent.
- Acid Extractibles: Examples include p-chloro-m-cresol, 2-chlorophenol, 4-nitrophenol, and pentachlorophenol. These are extracted using an acidic solvent.
- Volatile Organics (VOCs): Examples include benzene, carbon tetrachloride, and chloroform. These compounds readily evaporate at room temperature. The EPA's TO-15 method specifically analyzes these. EPA Air Method, Toxic Organics - 15 (TO-15)
- Total Toxic Organics (TTOs): This is a regulatory term encompassing a list of specific organic pollutants. The EPA sets limits for TTOs in various effluent discharge guidelines. The specific compounds included vary depending on the regulation. Guidance Manual for Implementing Total Toxic Organics (TTO) Total Toxic Organics (TTO) Effluent Guidelines Part 433 Examples include acenaphthene, acrolein, acrylonitrile, benzene, benzidine, and carbon tetrachloride. Total Toxic Organics (from 40 CFR part 433 subpart A)
Beyond these classifications, a broader range of toxic organic chemicals exist, including pharmaceuticals, pesticides, plastics, fuels, solvents, explosives, surface coatings, adhesives, disinfectants, and fire retardants. Toxic Organic Chemicals | SpringerLink
The EPA provides methods for determining various toxic organic pollutants in ambient air. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air
Regulatory Aspects
Regulations often focus on managing toxic organics through Total Toxic Organics (TTO) limits in wastewater discharge, as demonstrated by examples from the EPA and other regulatory bodies. Management plans (like TOMPs) can sometimes replace routine TTO monitoring. EPA Guidance for Toxic Organic Management Plans Proper storage and disposal procedures are also crucial. Pretreatment and National Pollutant Discharge Elimination System
