By 202380261
Discussion
In order for a chemical substance to have any effect, it must first enter the body. Living organisms can ingest them, inhale them, or absorb them through their skin (Figure 7). They may also travel inside the body via mucous in the nose, eye, or ear canals. These pathways are termed routes of exposure.
Absorption is the mechanism by which a substance passes through and enters the body. Yet, before it is absorbed, the substance must be available to be transported and processed by the body.
Bioavailability describes the extent to which a chemical can be absorbed by the organism's system. For example, in order for salt to increase blood pressure in the body, it must be ingested orally in large quantities. If a large quantity of salt is poured onto the skin, it cannot readily travel inside to cause an increase in blood pressure.
After the chemical substance is absorbed, it is distributed throughout the body. Typically, it is distributed from the bloodstream to cells or a particular storage site(s). A storage site might or might not be where the toxicity occurs. Sometimes, it may be used as a protective barrier since the substance is not freely moving.
The absorbed substance can also undergo metabolic changes (biotransformation) at the site.
Finally, the substance is passed outside of the body (excretion) via such means as sweat, tears, saliva, milk, bile, and feces.
Inhalation
Do we breathe it in? This is the most common route of entry.
Does it pass through the skin, eyes or other membranes?
Injection
Does it enter through a puncture or cut?
Source: https://www.oshacademy.com/courses/training/705-hazard-communication-program/705-2-4.php