Process Safety Flashcards
Toxicology
What is a toxicant?
chemical or physical agent - includes dust, fibres, noise and radiation
what is toxicity
property of the agent describing its effect on biological organisms
what is a toxic hazard
likelihood of damage to biological organisms based on exposure resulting from transport and other factors of usage.
what is the difference between toxicity and a toxic hazard
the toxic hazard that is presented by a substance can be reduced using appropriate hygiene techniques.
Toxicity cannot be changed
what are the four entry routes of a toxicant
- ingestion
- inhalation
- injection
- dermal absorption
which allows for absorption into blood fastest (give fastest to slowest)
- injection
- inhalation
- ingestion
- dermal
What are the effects of a toxicant on the GI tract
toxicants have biggest effect on area when ingested. Airborne particles lodge in mucous of upper respiratory tract.
What are rate and selectivity of absorption dependent on
type of chemical, molecular weight, molecule size, shape, acidity, susceptibility to attack intestinal flora, rate of movement through tract
how does the skin play a part in toxicants entering organisms
dermal absorption and injection
how can absorption through the skin occur
through hair folicles and sweat glands
how does skin change in absorption capabilities around the body
skin on palm- thicker than elsewhere, but has increased porosity and absorbs toxicant more highly
what does increased presence of water in the skin do
increased permeability and absorption.
what are the two areas where toxicants can impact the respiratory system
- upper respiratory system: nose, sinuses, mouth, pharynx, larynx, trachea
- lower respiratory: lungs and smaller structures - bronchi and alveoli
how are toxicants eliminated from biological organisms
- excretion: through kidneys, liver, lungs, other
- detoxification: changing chemical into something less harmful (bio transformation)
- storage: in fatty tissue
what are irreversible affects of toxicants
- carcinogen (cancer)
- mutagen (chromosomal damage)
- reproductive hazard (reproductive system damage)
- teratogen (birth defects)
