Patty's Industrial Hygiene, Evaluation and Control

How will all of this affect the future practice of industrial hygiene? In the Preface to the fourth edition of Patty's, George and Florence Clayton suggested that the future of industrial hygiene is limited only by the narrowness of vision of its practitioners.

I have relied extensively on the well‐written Preface by Robert Harris, Editor of the fifth edition of Patty's Industrial Hygiene . In it I saw a sweeping, but still succinct, review not only of Patty's publications but also of the practice of industrial hygiene itself. His writing is as timely in 2021 as it was 20 years ago.

Occupational and environmental hygiene professionals must be aware of the changes likely to take place, and to develop strategies to assure the profession's full participation in protecting the health and safety of workers and the environment of both today and tomorrow. Our participation, locally, nationally, and globally, will continue to be greatly needed in the coming years.

Barbara Cohrssen

San Francisco, California

1 kilometer = 0.6214 mile

1 meter = 3.281 feet

1 centimeter = 0.3937 inch

1 micrometer = 1/25,4000 inch = 40 micro inches = 10,000 Angstrom units

1 foot = 30.48 centimeters

1 inch = 25.40 millimeters

1 square kilometer = 0.3861 square mile (U.S.)

1 square foot = 0.0929 square meter

1 square inch = 6.452 square centimeters

1 square mile (U.S.) = 2,589,998 square meters = 640 acres

1 acre = 43,560 square feet = 4047 square meters

1 cubic meter = 35.315 cubic feet

1 cubic centimeter = 0.0610 cubic inch

1 cubic foot = 28.32 liters = 0.0283 cubic meter = 7.481 gallons (U.S.)

1 cubic inch = 16.39 cubic centimeters

1 U.S. gallon = 3,7853 liters = 231 cubic inches = 0.13368 cubic foot

1 liter = 0.9081 quart (dry), 1.057 quarts (U.S., liquid)

1 cubic foot of water = 62.43 pounds (4°C)

1 U.S. gallon of water = 8.345 pounds (4°C)

1 kilogram = 2.205 pounds

1 gram = 15.43 grains

1 pound = 453.59 grams

1 ounce (avoir.) = 28.35 grams

1 gram mole of a perfect gas 24.45 liters (at 25°C and 760 mm Hg barometric pressure)

1 atmosphere = 14.7 pounds per square inch

1 foot of water pressure = 0.4335 pound per square inch

1 inch of mercury pressure = 0.4912 pound per square inch

1 dyne per square centimeter = 0.0021 pound per square foot

1 gram‐calorie = 0.00397 Btu

1 Btu = 778 foot‐pounds

1 Btu per minute = 12.96 foot‐pounds per second

1 hp = 0.707 Btu per second = 550 foot‐pounds per second

1 centimeter per second = 1.97 feet per minute = 0.0224 mile per hour

1 footcandle = 1 lumen incident per square foot = 10.764 lumens incident per square meter

1 grain per cubic foot = 2.29 grams per cubic meter

1 milligram per cubic meter = 0.000437 grain per cubic foot

To convert degrees Celsius to degrees Fahrenheit: °C (9/5) + 32 = °F

To convert degrees Fahrenheit to degrees Celsius: (5/9) (°F − 32) = °C

For solutes in water: 1 mg/liter 1 ppm (by weight)

Atmospheric contamination: 1 mg/liter 1 oz/1000 cu ft (approx)

For gases or vapors in air at 25°C and 760 mm Hg pressure:

To convert mg/liter to ppm (by volume): mg/liter (24,450/mol. wt.) = ppm

To convert ppm to mg/liter: ppm (mol. wt./24,450) = mg/liter

Factors for conversion of some units

Mg/L × 28.32 = Mg/cubic foot

Mg/L × 1000 = Mg /cubic meter

Mg/cubic foot × 35.314 = Mg/cubic meter

Mg/cubic meter × 0.2832 = Mg/cubic foot

CONVERSION TABLE FOR GASES AND VAPORS a( Milligrams per liter to parts per million, and vice versa; 25°C and 760 mm Hg barometric pressure )

aA. C. Fieldner, S. H. Katz, and S. P. Kinney, “Gas Masks for Gases Met in Fighting Fires,” U.S .