PAFT Programme for Alternative Fluorocarbon Toxicity Testing

Acute Toxicity
	The effect of a single high-level exposure, as would occur during accidental release.
Ames Assay
	A preliminary test for mutagenicity on bacteria; designed primarily as a rapid screen for possible carcinogens. Both false positives and false negatives are common, so the test is never used on its own.
Benign (of a tumor)
	Not malignant.
Carcinogenic / Carcinogenicity
	A term applied to substances causing cancer.
Cardiac Sensitization
	An effect in which the heart is rendered more sensitive to the action of Adrenalin and similar drugs. This can result in sudden heart failure.
Chromosome
	A part of the cell nucleus that carries genetic information (genes).
Chronic Toxicity
	An assessment conducted over the lifetime of the test animals to see if the chemical exposure results in late-in-life toxicity.
Clastogen
	An agent that produces changes in the chromosome.
Cytochrome P-450
	A group of multi-functional enzymes that are frequently involved in the breakdown of chemicals within the body.
Cytogenetics
	The study of changes in chromosomes. A positive response, in itself, does not indicate that a material is a carcinogen.
Developmental Toxicity (Teratology)
	The potential of a compound to cause birth defects.
Dominant Lethal Test
	A test for mutagenicity. Usually male animals are exposed to the test substance and then mated with unexposed females. The females are monitored for early embryonic deaths.
Environmental Toxicity (Ecotoxicity)
	A chemical's potential to affect living organisms in the environment.
Genotoxicity
	The ability of a material to cause damage to genes or chromosomes. Genotoxicity studies provide an early screen for possible cancer-inducing activity.
Hyperplasia
	The increase in number of cells per unit volume.
Inhalation
	The act of taking into the body by breathing in (inhaling).
In Vitro
	In cultured cells or organisms.
In Vivo
	In the whole animal.
LC50
	Lethal concentration 50%; a measure of acute toxicity. The concentration of a substance in air expected to kill half of a group of test animals exposed for a specified period.
LD50
	Lethal dosage 50%; a measure of acute toxicity. The dose of a substance expected to kill half of a group of test animals exposed for a specified period.
Leydig Cells
	Cells in the testis responsible for production of the male hormone testosterone.
Lipids
	Generic term for oils and fats found in living tissue; may also include compounds such as phospholipids and derivatives such as steroids.
Lymphocyte
	A mobile cell found in lymph and blood, and responsible for the development of specific immunity (e.g., to a disease).
Metabolic Activation
	Conversion by enzymes of a chemical from one form to a more active form.
Metabolism
	Chemical processes taking place in living cells.
Mouse Micronucleus Assay
	An in vivo test for clastogens using a mouse.
Mutagenic Effect / Mutagenicity
	A change in the amount or structure of the genetic material.
Neurotoxicity
	Toxicity of the nervous system.
NOEL
	No Observed Effect Level. The maximum dose at which no signs of harm are observed.
Oral Route
	The act of taking into the body by mouth or swallowing (ingestion).
Plasma
	Fluid that remains after the removal of red and white blood cells and platelets from whole blood.
Reprotoxicity
	Adverse effects on the reproductive system.
Sub-chronic Toxicity
	The effects obtained after repeated exposures (usually 90 days) to a chemical.
Teratology
	The study of the potential of a compound to cause birth defects.
Unscheduled DNA Synthesis Test
	A test for the presence of repair activity in the genetic material, which might indicate damage.

September 1995

Last updated October 11, 1996