CHAPTER 7 GASES AND VAPOUR Flashcards
Define “gas” in the context of occupational health.
A formless state of matter with low density and viscosity at room temperature, uniformly distributing in any container
What is “vapor”?
The gaseous form of a substance that exists as a solid or liquid at normal temperature and pressure
Name two examples of asphyxiants.
Carbon dioxide (CO₂)
carbon monoxide (CO).
List some types of health effects from gas and vapor exposure. 9
Asphyxiants,
irritants,
anesthetics,
hepatotoxins,
nephrotoxins,
neurotoxins,
hematopoietic toxins,
pulmonary toxins,
carcinogens.
Describe personal sampling in air quality monitoring.
A battery-powered pump worn by workers in the breathing area to measure airborne contaminants.
What is absorption in sampling methods?
A molecular process where molecules are dispersed in another substance, requiring a liquid sampling medium.
What is adsorption in sampling methods?
A process where molecules are reversibly bound to a solid surface, commonly used for gases and vapors.
Name a common adsorbent material used in gas sampling.
Activated charcoal for hydrocarbons or silica gel for alcohols and aldehydes.
What is passive sampling?
A method relying on diffusion, where contaminated molecules move naturally from high to low concentration on the sampler.
What is a gas dosimeter (dose badge)?
A lightweight badge used in passive sampling for monitoring gases like mercury or formaldehyde, convenient and economical.
What are direct-reading instruments used for?
Real-time measurement of contaminants, useful for immediate data,
control evaluation,
emergency response,
confined spaces.
Name two types of direct-reading instruments for gas monitoring.
Single and multiple gas monitors,
photoionization detectors (PID) like miniRAE and MSA Passport PID II.
