Math/Chem Associate Safety Professional Cert
What is a class A fire?
Ordinary combustibles wood, paper, cloth, trash, plastic
What 3 chemicals does fire involve?
Oxygen, heat, and fuel
How many classifications of fire are there?
5 Class A, B, C, D, K
What pH indicates a neutral solution?
7
A large exposure in a short time is called what?
Acute toxicity
What is electric current measured in?
Amps (A)
What substance fire extinguishers are used for class B & C fires?
Carbon dioxide, clean agent, halogenated
Low level exposure for a long period of time
Chronic toxicity
What is a class D fire
Combustible metals like potassium, sodium, aluminum, magnesium
Dose =
Concentration x Time
What is a class K fire?
Cooking oils and fat
What is a highly reactive substance that damages human tissue upon contact?
Corrosive material
Ohms law states that current is ___________ to voltage
Current is directly proportional to voltage
What is the assigned waste code for corrosive material
D002
What is electrical resistance?
Difficulty of passing a current through a conductor (measured in Ohms Ω)
What substance fire extinguisher is best used for class D fires?
Dry powder
What is a class C fire
Energized electrical equipment
What does it mean when a pH is neutral? What ions in particular?
Equilibrium of hydrogen and hydroxyl ions
A rapid self sustaining chemical reaction with oxygen, heat, and fuel?
Fire
The difference between flammable gas and flammable liquid is ______________ are ready to burn ______________ must be vaporized to burn
Flammable gas is ready Flammable liquid must be vaporized
What is a class B fire?
Flammable liquid or gasses (paint included)
What pH value indicates a base?
Greater than > 7
Current (I) =
I = V / R V= voltage R= resistance
What conditions must be met for vapor to burn ?
If concentration in air is BETWEEN lower flammability limit and upper flammability limit
What is the dose of toxicity that kills 50% of a sample population called?
LD50
What is the formula for Le Chatelier's mixing rule?
LFLmix = 1 / Σ(fn/LFLn) LFLmix= lower flammability limit of mixture Fn= fractional concentration of component n LFLn = Lower flammability limit of component n
What do you use to calculate the flammable range of a mixture of gases?
Le Chatelier's Mixing Rule
What pH value indicates acid?
Less than < 7
What can be used to test a pH of a solution?
Litmus paper
The concentration of free hydrogen ions being greater than hydroxyl will be a high or low pH value?
Low pH value.
What does the Toxic Equivalency Factor compare all toxins to?
Most toxic dioxin
The limit on the amount of exposure a worker can have to a hazardous substance or agent is called what?
Permissible exposure limit (PEL)
Corrosive material is considered for what in particular?
Strong acid/ strong base
How does the EPA define corrosive waste?
Substance that eroded steel at a rate of 1/4 inch per year or greater or has a pH less than 2 or greater than 12.5
How does a Litmus paper show results?
Substances with low pH will turn the blue paper red Substances with a high pH will turn red litmus paper blue
What formula is used to calculate the toxic equivalency of a compound?
TEQ= Σ(Mi x TEFi) ___% of substance x a TEF of ____
What does the pH scale measure?
The acidity or alkalinity (basicity) of a solution
What is electric voltage?
The difference in electrical potential energy between 2 points per unit electric charge. Measured in Volts (V)
The PEL is usually given as a _______ over an ___ hour period
Time weighted average over an 8 hour period
If the concentration is lower than the LFL, what is the mixture of gas and atmosphere considered?
Too lean
If concentration is higher than the UFL, what is the gas and atmosphere considered?
Too rich
Resistance (R) =
V / I V = voltage I = current
Voltage =
V = I x R I = current R = resistance
What are the 3 primary parameters of electricity
Voltage, current, and resistance
What substance fire extinguishers are good for class A fires?
Water & foam
What substance is best used for class K fires?
Wet chemical
How to find the concentration of a solution
[H+] = 10^pH [OH-] = 10^pOH Answer is #.## x 10^# M
How to calculate pH of a solution (formula)
pH = -log[H+] H= concentration of hydrogen ions pOH= -log[OH-] OH= concentration of hydroxide ions pH+pOH= 14 ALWAYS
What does the pH scale range from?
0-14