All flashcards
Flashcard 1: Identify one benefit of using LD50 data.
Answer: Quantifies acute toxicity. Provides standardized comparison of substance dangers.
Flashcard 2: Calculate LD50 for 50 kg rat exposed to 50 mg/kg lethal dose.
Answer: 2,500 mg. Total lethal dose: 50 kg×50 mg/kg.
Flashcard 3: Name a regulatory body that uses LD50 data in assessments.
Answer: EPA (Environmental Protection Agency). Uses toxicity data for chemical approval decisions.
Flashcard 4: What does LD50 not account for?
Answer: Chronic effects. Only measures immediate lethal effects, not long-term damage.
Flashcard 5: LD50 is used in regulatory assessments for what purpose?
Answer: Chemical safety evaluation. Determines safe exposure limits for human health.
Flashcard 6: What alternative metric to LD50 measures chronic toxicity?
Answer: NOAEL (No Observed Adverse Effect Level). Measures highest safe dose without observable harm.
Flashcard 7: Which is more toxic: a substance with LD50 of 10 mg/kg or 200 mg/kg?
Answer: 10 mg/kg. Lower LD50 means higher toxicity.
Flashcard 8: What is the threshold dose in the context of LD50?
Answer: Minimum dose causing effect. Lowest dose that produces measurable toxic effects.
Flashcard 9: Which species variability is a concern in LD50 tests?
Answer: Inter-species differences. Results may not translate between different species.
Flashcard 10: In LD50 context, what is acute toxicity?
Answer: Short-term exposure effect. Immediate harmful effects from single exposure event.
Flashcard 11: What does LD50 not account for?
Answer: Chronic effects. Only measures immediate lethal effects, not long-term damage.
Flashcard 12: What is a common use of LD50 data in agriculture?
Answer: Pesticide regulation. Determines safe application rates for crop chemicals.
Flashcard 13: Which organism is often used in LD50 tests?
Answer: Rats. Common laboratory animal for toxicity studies.
Flashcard 14: What is the main goal of alternative toxicity tests to LD50?
Answer: Reduce animal testing. Develops methods using fewer or no animals.
Flashcard 15: Name a regulatory body that uses LD50 data in assessments.
Answer: EPA (Environmental Protection Agency). Uses toxicity data for chemical approval decisions.
Flashcard 16: What does a lower LD50 value indicate?
Answer: Higher toxicity. Less substance needed to kill half the population.
Flashcard 17: How is LD50 expressed in terms of test subject's weight?
Answer: mg of substance per kg of body weight. Accounts for body weight differences between subjects.
Flashcard 18: Which factor can influence LD50 results?
Answer: Species of test organism. Different species have varying sensitivities to toxins.
Flashcard 19: Which method reduces the number of animals in toxicity testing?
Answer: Up-and-Down Procedure. Sequential testing method using fewer animals.
Flashcard 20: LD50 is used in regulatory assessments for what purpose?
Answer: Chemical safety evaluation. Determines safe exposure limits for human health.
Flashcard 21: Define LD50 in toxicology.
Answer: Dose lethal to 50% of test population. Statistical measure of acute toxicity.
Flashcard 22: Calculate LD50: 100 rats, 30 mg/kg dose lethal to 50.
Answer: 30 mg/kg. Given information directly states the LD50 value.
Flashcard 23: What is a common alternative to LD50 for acute toxicity testing?
Answer: LC50 (Lethal Concentration 50%). Measures lethal concentration in air or water.
Flashcard 24: Which term describes the lowest dose causing an observed effect?
Answer: LOAEL (Lowest Observed Adverse Effect Level). Defines the minimum dose causing detectable harm.
Flashcard 25: What is the primary purpose of determining LD50?
Answer: Assess substance toxicity. Provides standardized measure for comparing chemical hazards.
Flashcard 26: Which species variability is a concern in LD50 tests?
Answer: Inter-species differences. Results may not translate between different species.
Flashcard 27: Identify a variable that affects LD50 outcomes.
Answer: Genetic makeup. Individual genetic differences affect toxin sensitivity.
Flashcard 28: What does LD50 data help determine in drug development?
Answer: Initial dosage limits. Establishes starting safety parameters for clinical trials.
Flashcard 29: In LD50, what does '50%' specifically refer to?
Answer: 50% mortality of test population. Percentage of test subjects that die from the dose.
Flashcard 30: What is the threshold dose in the context of LD50?
Answer: Minimum dose causing effect. Lowest dose that produces measurable toxic effects.