Gases and Vapors: Background and Principles

A comprehensive set of vocabulary flashcards based on the introductory lecture on gases and vapors, focusing on important terms and their definitions within environmental health and safety.

Gases

Fluids that expand to occupy the entire space available.

Vapors

The gaseous form of a chemical that is normally a liquid or solid at normal temperature and pressure.

Normal Temperature and Pressure (NTP)

Defined as 25 degrees Celsius and one atmosphere of pressure.

Standard Temperature and Pressure (STP)

Defined as 0 degrees Celsius and one atmosphere of pressure.

Ideal Gas Law

The relationship between pressure, volume, number of moles, gas constant, and temperature.

Combined Gas Law

Describes the relationship between the initial and final states of a gas sample.

Vapor Pressure

The pressure of vapor in equilibrium with its liquid form at a given temperature.

Vapor Hazard Ratio

A ratio used to evaluate the relative hazard of two or more chemicals based on saturation vapor concentration and exposure limits.

Immediate Danger to Life or Health (IDLH)

Concentrations of airborne contaminants that pose immediate hazards to life or cause irreversible health effects.

Explosive Atmospheres

Conditions where a mixture of vapor and air can spontaneously ignite in the presence of an ignition source.

Lower Explosive Limit (LEL)

The minimum volume of vapor in air that can ignite.

Upper Explosive Limit (UEL)

The maximum volume of vapor in air that can ignite.

Law of Partial Pressures

States that the total pressure exerted by a mixture of gases is equal to the sum of the individual pressures.

Oxygen Deficient Environment

Environment with less than 19.5% oxygen by volume.

Volatilization

The process where a liquid or solid converts to a gas.

Asphyxia

Condition caused by lack of oxygen leading to suffocation.

Systemic Effects

Body-wide health impacts as opposed to local effects.

Acetone

A chemical with higher vapor pressure and greater inhalation risk compared to phenol.

Phenol

A chemical with lower exposure limits than acetone despite having higher safety thresholds.

Saturation Vapor Concentration

The concentration of vapor above a liquid at equilibrium.

Altitude Effects

Changes in gas behavior and oxygen availability due to elevation.

Carbon Monoxide

A colorless, odorless gas that can cause asphyxia.

Cancer Risk

Health risk associated with exposure to chemicals like benzene and vinyl chloride.

Carbon Tetrachloride

A toxic substance known for nervous system effects.

Chloroform

A chemical that may have systemic health effects.

Inhalation Exposure

The risk or potential harm from breathing in vapors or gases.

Respiratory Protection

Safety measures and equipment used to protect against inhaling harmful substances.