B. During the first 30 minutes of an incident.
Vaopr fumes are in a valley the wind or other weather conditions change
during the first 30 minutes of an incident.
These distances can be used during the first 30 minutes of an incident.
To ensure safety
During the first 30 minutes.
In the orange bordered pages initial isolation and protective action distances are provided under public safety. For those substances that are toxic inhalation hazard,s they are highlighted in the yellow and blue bordered pages and their evacuation distances are located in the green bordered pages.
This section contains a table which lists, by ID number, TIH materials, including certain chemical warfare agents, and water-reactive materials which produce toxic gases upon contact with water. The table provides two different types of recommended safe distances which are "Initial isolation distances" and "Protective action distances."
Green
vapor fumes are in the valley and the wind or other weather conditions change
a hazardous material is exposed to fire
When the materials are exposed to fire. (or on fire, whatever)
Short distances Medium distances and Long distances
This section contains a table which lists, by ID number, TIH materials, including certain chemical warfare agents, and water-reactive materials which produce toxic gases upon contact with water. The table provides two different types of recommended safe distances which are "Initial isolation distances" and "Protective action distances."
Green section, Table of Initial Isolation and Protective Action Distances.
green
Entries highlighted in green can be found listed by ID number in the Initial Isolation and Protective Action Distances section ( Green Section ) at the back of the ERG. All listings in this section are considered Toxic Inhalation Hazards (TIH) and have suggested isolation and protective distances following each (TIH) entry. The section is made up of two tables with Table 1 listing all (TIH)s including those that react when spilled in water. Table 2 lists only (TIH)s that produce large amounts of (TIH) Gases when spilled in water plus the gas produced during the reaction.
To find protective distances if there is no fire at a hazardous materials incident, refer to the green section of the North American Emergency Response Guide.