Signs vs.


Individuals may respond differently to potential vapor exposure, depending on sensitivity. When a worker undergoes evaluation, the medical professional may document signs or symptoms. These terms are not limited to vapors exposure, and can generically be defined as follows:

  • Symptoms: can only be described by the individual experiencing them (subjective)

  • Signs: physical manifestation of injury, illness or disease; visible to others (objective)


Effects may be short or long term.

  • Acute (short-term): relatively quick onset (usually minutes to days) after a brief exposure to a relative high concentration of material. The effect may be local or systemic.
    • Local effects: occur at the site of contact.
    • Systemic effects: occur if the substance has been absorbed into the body from its initial contact point, transported to other parts of the body, and cause adverse effects in susceptible organs.
  • Chronic (long-term): long period of time (years) between exposure and injury. These effects may occur after apparent recovery from acute exposure of as a result of repeated exposures to low concentrations of materials over a period of years.