OECD Flashcards
Measures the adverse effects that occur within a short period of time
ACUTE TOXICITY TESTS
ACUTE TOXICITY TESTS endpoint
Death and signs of toxicity
Information gained from these ACUTE TOXICITY TESTS:
- Basis for _________________
- Identify the mode of ___________ of a substance
- Information on ____________ associated with target-organ toxicity
- For use in___________ and ___________t of toxic reactions in humans
- Basis for hazard classification
- Identify the mode of toxic action of a substance
- Information on doses associated with target-organ toxicity
- For use in diagnosis and treatment of toxic reactions in humans
Problems in extrapolation from experimental animals to humans:
- Differences in
- metabolic pathways * dermal penetration * mode of action
Advantages of using experimental animals in testing procedures:
* possibility of clearly defined ________________
* amenity to controlled ____________ and controlled _________________ of exposure
* possibility of ________________ examination of all tissues following necropsy
- possibility of clearly defined genetic constitution
- amenity to controlled exposure and controlled duration of exposure * possibility of detailed examination of all tissues following necropsy
This focuses on the Determination of the median lethal dose (LD50)
Acute oral testing
This focuses on the Timing of lethality following acute chemical exposure
Acute oral testing
This focuses on the Observation of the onset, nature, severity, and reversibility of toxicity
Acute oral testing
Logarithmic expansion from a starting dose
CLASSICAL LD50 TEST
CLASSICAL LD50 TEST starting dose
10 mg/kg.
T/F: In Classical LD50 Test, each dose level necessitates the use of a group of test animals
True
If many dose levels are to be tested, then the classical LD50 test presents the following disadvantages:
expensive and time consuming
OECD methods are employed to
- Decrease the number of animals necessary
- Reduce study duration
- Reduce the amount of test substance needed
Aims to identify the appropriate hazard class for new chemicals
FIXED DOSE PROCEDURE
T/F: FIXED DOSE PROCEDURE does not provide a point estimate of the LD50.
True
T/F: In Fixed Dose Procedure, Animals are tested sequentially at one of four doses (5, 50, 300, or 2000
mg/kg BW).
True
In Fixed Dose Procedure, Once clear signs of ___________ appear, additional animals (females or the more ___________ sex) are dosed at that level
toxicity; sensitive
T/F: In Fixed dose procedure, Subsequent groups of animals may receive doses at higher or lower levels, if necessary, depending on the outcome of the previous group
True
Aims to identify the appropriate hazard and labeling classification
ACUTE TOXIC CLASS METHOD
Provides a RANGE for lethality rather than a point estimate of the LD50
ACUTE TOXIC CLASS METHOD
In ACUTE TOXIC CLASS METHOD, Groups of three animals receive one of the four or five doses:
5, 50,
300, 2000 and, if necessary, 5000 mg/kg body weight.
In Acute toxic class method, Depending on the _________________ of the first group of animals, three or more animals may receive the same or a higher or lower dose.
survival or mortality
The number of animals that ______________determines the classification decisions. in acute toxic class method
survive or die
Employs sequential dosing, using only a single animal at each step.
UP AND DOWN PROCEDURE
The dosage depends on whether the previously dosed animal lives or dies.
UP AND DOWN PROCEDURE
This test provides a point estimate of lethality and confidence intervals and can be used to evaluate lethality up to 5000 mg/kg.
UP AND DOWN PROCEDURE
UP AND DOWN PROCEDURE is a equential limit test uses up to __________ animals.
five
in UP AND DOWN PROCEDURE Default dose spacing is
3.2 times the previous dose.
The starting dose should be slightly below the estimated LD50
UP AND DOWN PROCEDURE
In UP AND DOWN PROCEDURE, If no data are available to estimate the LD50, the starting dose is
175 mg/kg
