CPC CPC Environmental Chemistry & Regulations 1 — Questions and Answers
Question 1: Under RCRA (Resource Conservation and Recovery Act), a waste is classified as hazardous if it exhibits which characteristic?
- High viscosity
- Ignitability, corrosivity, reactivity, or toxicity (Correct answer)
- Strong odor
- High molecular weight
Correct answer: Ignitability, corrosivity, reactivity, or toxicity
RCRA identifies hazardous waste by four characteristics: ignitability (flash point <140°F), corrosivity (pH ≤2 or ≥12.5), reactivity, and toxicity (TCLP-based leaching).
Question 2: Which US federal agency is primarily responsible for regulating chemical substances under TSCA (Toxic Substances Control Act)?
- FDA
- OSHA
- EPA (Correct answer)
- CDC
Correct answer: EPA
The EPA administers TSCA, which authorizes it to require reporting, record-keeping, and testing of chemical substances, and to restrict use of chemicals posing unreasonable risks.
Question 3: The concept of bioaccumulation refers to the process by which:
- Chemicals degrade rapidly in living tissue
- Concentrations of substances increase within an organism over time (Correct answer)
- Bacteria decompose organic pollutants
- Chemicals are excreted efficiently by aquatic organisms
Correct answer: Concentrations of substances increase within an organism over time
Bioaccumulation occurs when an organism absorbs a substance faster than it can metabolize or excrete it, leading to increasing internal concentrations over time.
Question 4: In the US Clean Air Act, a National Ambient Air Quality Standard (NAAQS) is set for which pollutant?
- Chlorofluorocarbons (CFCs)
- Particulate matter (PM2.5) (Correct answer)
- Polychlorinated biphenyls (PCBs)
- Dioxins
Correct answer: Particulate matter (PM2.5)
EPA sets NAAQS for six criteria pollutants including PM2.5, PM10, ozone, NO2, SO2, CO, and lead, specifying maximum allowable atmospheric concentrations.
Question 5: Which process describes the movement of contaminants from soil into groundwater?
- Volatilization
- Photodegradation
- Leaching (Correct answer)
- Adsorption
Correct answer: Leaching
Leaching is the downward movement of dissolved contaminants through soil with percolating water, potentially contaminating underlying aquifers.
Question 6: The octanol-water partition coefficient (Kow) is used to predict a chemical's tendency to:
- React with metals in soil
- Bioaccumulate in fatty tissues and partition into organic matter (Correct answer)
- Volatilize from water surfaces
- Undergo photolysis in sunlight
Correct answer: Bioaccumulate in fatty tissues and partition into organic matter
A high log Kow (>3) indicates a chemical is hydrophobic and lipophilic, predicting it will partition into organic matter and bioaccumulate in fatty tissues.
CPC CPC Environmental Chemistry & Regulations 1
Under RCRA (Resource Conservation and Recovery Act), a waste is classified as hazardous if it exhibits which characteristic?