Environmental effects Terminology of the environmental effects of elements and compounds

Environmental effects

Terminology of the environmental effects of elements and compounds

LC50 Lethal Concentration 50. An LC50 value is the concentration of a material in air that will kill 50% of the test subjects (animals, typically mice or rats) when administered as a single exposure (typically 1 or 4 hours). This value gives you an idea of the relative toxicity of the material. This value applies to vapors,dusts, mists and gases. Solids and liquids use the closely related LD50 value (50% lethal dose). LD50 Lethal Dose 50. It’s the amount of a solid or liquid material that it takes to kill 50% of test animals (for example, mice or rats) in one dose. Toxic Toxic is defined by OSHA (Ocupational Safety and Health Administration) 29 CFR 1910.1200 App A as a chemical which falls in any of these three categories: A chemical that has a median lethal dose (LD50) of more than 50 milligrams per kilogram but not more than 500 milligrams per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each. A chemical that has a median lethal dose (LD50) of more than 200 milligrams per kilogram but not more than 1,000 milligrams per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each. A chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million but not more than 2,000 parts per million by volume of gas or vapor, or more than two milligrams per liter but not more than 20 milligrams per liter of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each. Highly toxic Highly toxic is defined by OSHA (Ocupational Safety and Health Administration) as: A chemical that has a median lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each. A chemical that has a median lethal dose (LD50) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each. A chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less of gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each. Toxicology Toxicology is the study of the nature, effects, detection, and mitigation of poisons and the treatment or prevention of poisoning. Toxin A toxin is a toxic substance. Toxins that affect only specific types of cells or organs are called cytotoxins.