Demystifying Hazmat Chemistry

STUDENT HANDOUT
DEMYSTIFYING HAZMAT CHEMISTRY
Spill Estimation Chart
Developed by Kevin Smith, Deputy Fire Marshal - Hazardous Materials
Chino Valley Independent Fire District
This table was constructed based on assumptions used by FEMA and the U.S. EPA for emergency
planning purposes. The data and formulations are specifically from Appendix G, “Equations
Used for the Estimation of Vulnerable Zones,” Technical Guidance for Hazard Analysis (1987),
and from the Unit Equivalency Table, page A-4, of the Handbook of Chemical Hazard Analysis
Procedures.
* Weight assumes a specific gravity of 1. For true
weight, multiply the weight shown by the specific
gravity of the product. (Specific gravity data is available
on MSDSs and in various reference sources.
Using the Information with Circular Spills
This chart assumes that the spill is a circular one and
that the spill is 0.033 feet (1 centimeter) deep. (Note:
These same calculations can be used for spills contained
within circular dikes.)
1. Determine either the radius or the diameter.
2. Read the “Gallons” and “Weight” columns in that row.
3. If the spill depth is either more or less than one centimeter,
multiply or divide the numbers as appropriate.
(If measuring in inches, convert inches to centimeters
by multiplying by 2.54.)
Using the Information with Rectangular Spills
If the spill is rectangular rather than circular, you must
first calculate the area of the spill to determine gallons
and pounds. (Note: These same calculations can be
used for spills contained within rectangular dikes.)
1. Figure the area by multiplying length times width.
2. Find the closest match in the “Area” column.
3. Read the “Gallons” and “Weight” columns in that row.
4. If the spill depth is either more or less than one centimeter,
multiply or divide the numbers as appropriate.
(If measuring in inches, convert inches to centimeters
by multiplying by 2.54.)
Conversion Factors
1 cubic foot = 7.48 gallons
1 cubic foot = 30.30 square feet at 1 cm deep
1 gallon spill = 4.05 square feet at 1 cm deep
1 gallon of water = 8.34 pounds
1 inch = 2.54 centimeters
Diameter = Radius x 2
Area = Pi x R 2 (3.14 x R 2 )
Continuing Challenge 2007 Page 37 © 2007 Firebelle Productions and CHES