Cancer An uncontrolled growth of abnormal cells, creating a tumor that can invade surrounding tissues and may spread (metastasis) to distant organs. Cancer Slope Factor A key risk assessment parameter derived by the EPA.  It is an estimate of the probability that an individual will develop cancer if exposed to a specified amount of chemical (mg/kg) every day for a lifetime. Carcinogen A compound which is capable of causing cancer. Carcinogenic The ability of a substance to cause cancer. Carcinogenicity The complex process whereby normal body cells are transformed to cancer cells. Case-Control Study A type of epidemiology study to investigate the cause of the toxicity.  It compares the exposure histories of humans who have a particular toxic effect with that of normal individuals. Ceiling Level The maximum allowable concentration of a chemical in the workplace for a specific period of time (usually 15 minutes). Cell Transformation The change of a cell from one form to another.  The term is generally used to denote the change from normal to malignant. Cholinergic Effect Neurological effects resulting from the transmission by acetylcholine of impulses across synaptic junctions between nerves. Cholestasis A liver condition in which excretion of bile salts via the bile duct is inhibited resulting in bile salts backing up into liver cells. Chromatography An analytic method to separate and identify the components of a complex mixture by the differential movement through a two-phase system.  The movement is effected by a flow of a liquid or a gas (mobile) phase, based on the physicochemical principles of adsorption, partition, ion exchange, exclusion, or a combination of these principles. Chromosome One of a group of structures that form in the nucleus of a cell during cell division.  Chromosomes, bearing the DNA, carry the genetic code for the organism. Chromosome Aberration Changes in chromosome structure. Chronic Dose Substance administered or received gradually over a long period of time (months to years). Chronic Effect An effect that either shows up a long time after an exposure (the latency period) or an effect that results from a long term (chronic) exposure. Cirrhosis A chronic condition of the liver in which liver cells are replaced by fibrous cells. CNS The central nervous system consisting of the brain and spinal cord. Cohort Study An epidemiology study in which a cohort (group) of individuals with exposure to a chemical and a cohort without exposure are followed over time to compare disease occurrence. Conjugation A metabolic process in which chemical groups are attached to foreign substances in the body, usually making the conjugated chemical more water soluble and easier to eliminate from the body. Control Group A group of animals or humans in a study that are treated the same as the exposed groups but without receiving the specific exposure. Cornea The transparent front surface of the eye. Corrosion Direct chemical action that results in irreversible damage at the site of contact.  It is manifested by ulceration, necrosis, and scar formation. Covalent Bond The joining together of atoms that results from sharing electrons. CPSC Consumer Product Safety Commission.  It is a federal agency responsible for protecting the public from toxins and other hazards present in consumer products. Cross-Sectional Study A type of epidemiology study that tests for the prevalence of a disease or clinical parameter among one or more exposed groups (e.g., the prevalence of respiratory conditions among furniture makers).