Transcript Hazardous Materials - Louisiana State University

Hazardous Materials
Chemical and Physical
Properties
Chemistry Rules
 Chemistry
and Physics can be fun!
 Chemicals add quality to some lives...
 Mixing chemicals can be exciting and
dangerous.
 Don’t try it at home…
 Have adult supervision!
Introduction
Hazardous Materials
Combustion

Combustion
– An exothermic
oxidation reaction

Combustion requires
– Fuel
– Heat
– Oxygen

HEAT
OXYGEN
Combustion can
occur spontaneously
– Phosphorous, Bacterial
activity
FUEL
Combustion
 Fuel
- comes in several
forms (vaporizes and
combines w/ Oxygen.)
 Heat - The heat of

combustion is due to the
rupture of chemical bonds
and the creation of new
compounds.
Oxygen - is not
combustible but supports
combustion/not needed if
another oxidizing agent is
present.
HEAT
OXYGEN
FUEL
Fire Tetrahedron
 Uninhibited
chain
reaction  Oxidizing agent Fuel
 Fuel  Temperature -
Temperature
Oxidizing
Agent
Uninhibited
Chain
Reaction
Detonation or Deflagration?
 Detonation:
1,250 feet/second
– Produces a
shockwave that
travels faster than the
speed of sound.

Deflagration:
– Does not produce a
lethal shockwave
Flashpoint
 The
minimum
temperature at
which sufficient
vapors are present to
form a combustible
mixture with air.
- 45 0 F
Autoignition Temperature
 The
minimum
temperature at
which rapid
combustion becomes
independent of any
external heat
supplies.
Carbon disulfide
194 0 F
Flammable (Explosive) Limits
The minimum
volume percent of a
material at which
ignition can occur.
Too Rich
 LEL -
 UEL -
The maximum
volume percent of a
material at which
ignition can occur
0 5
LEL
15
UEL
Too Lean
100
Flammable Ranges Examples:
 Gasoline
1.4% - 6%
 Ethyl Ether 1.9% - 36%
 Acetylene 2.5% - 100%
 Carbon monoxide 12.5% - 74%
Boiling Point
 Temperature
at
which a liquid
changes to a vapor.
 Vapor pressure
exceeds atmospheric
pressure.
 However, liquids
may evolve vapor
without boiling.
H2O
2120 F @ Sea Level
Boiling Point cont.
 High
Boiling Point-
– Skin Contact

Low Boiling Point– Inhalation
Skin
Lung
Specific Gravity
 The
ratio of the
density of a material
to the density of
water (water = 1.0)
– Materials > 1 sink
– Materials < 1 float
 Keep
in mind the
materials solubility
<
Gasoline 0.8
Xylene 0.9
>
Phenol 1.03
CCl4
H2SO4 1.8
H 2O 1
1.6
He
Vapor Density
The ratio of the
density of a gas to the
density of air (air =1)
 Light Vapors (<1)
generally rise and
dissipate faster.
 Heavy Vapors (>1)
generally move along
the ground and
disperse slowly

H2S
Vapor Pressure
 The
pressure exerted
by a volatile
substance.
 A measure of a
substances tendency
to emit or give off
vapors.
 Vapor pressure
increases with heat.
Atmospheric: 14.7
psia (760 mm/Hg or
1 atmosphere)
@ Sea Level
Propane
132 psig @ 62 degrees F
Solubility
The ability of one
substance to mix
uniformly with
another
 Can vary from 0% 100%
 Important in
determining health
effects, reactivity,
dispersion, etc..

Reactivity
 The
tendency of a
substance to
participate in a
chemical reaction.
Reactivity examples:
 Extremely
Reactive
– Aluminum alkyls

Highly Reactive
– Sodium metal with
water

Reactive
– Zinc with HCl
 Relatively
– Glass
Inert
Radioactivity
 Three
common
types that may be
encountered at
certain sites:
– Alpha
– Beta
– Gamma
Radioactivity Cont.
 Alpha
-
–
–
–
–
Is positively charged
Has mass and energy
Is a large particle
A sheet of paper can
provide adequate
protection
– Route of exposure
» Inhalation, Ingestion
Radioactivity cont.
 Beta
-
– Is negatively charged
– Has mass and energy
– Smaller than alpha,
and can travel
farther
– Requires a greater
degree of density to
shield from
– Route of exposure
» Inhalation, Ingestion
Beta
Radiation cont.
 Gamma
-
– Pure electromagnetic
energy
– Wave-like rather
than particulate
– Waves pass through
all materials to some
degree
– Normal PPE will not
prevent exposure
I think I should
check my
compatibility
charts?!
Radiation
 Has
no warning
properties
 Rules of thumb to
avoid overexposure:
– Time
– Distance
– Shielding
Corrosivity
 pH
- the value taken
to represent the
acidity or alkalinity
of aqueous acid-base
systems
 pH of 6-0: excess of
H+ Ions (Acid Side)
 pH of 8-14: excess of
OH- Ions (Alkaline
Side)
0
pH = log 101-----------[H +]
7
14
pH Value (Multiply by 10)
1
1,000,000 8
2
100,000 9
3
10,000 10
1,000
4
1,000 11
10,000
5
100 12
100,000
6
10 13
10
100
Toxicology
The Science that deals with the
interaction between chemical and
physical agents with body systems to
produce a response in organisms.
Toxicology
 The
study of poisons and toxic substances
 Poisons kill
 Toxins kill
 Humans kill
Terminology






Threshold Limit Values
(TLVs) Time Weighted Average
(TWA)
Short Term Exposure
Limit (STEL)
Ceiling (C)
Immediately Dangerous
to Life and Health
(IDLH)
Permissible Exposure
Level (PEL)
Dose-Response Terminology

Dose– Introduction of a substance by any route
other than inhalation. (Ingestion & Skin
Absorption)

Concentration– Introduction of an airborne substance by
inhalation
TDlo, TClo, LDlo, LClo, LD50, LC50
Toxicity Rating Scheme
Toxicity Rating Scheme and Comparison of Selected Chemicals*
Probable Oral Lethal Dose for Humans
Toxicity Rating or Class
Dose
For Average Adult
Representative Chemical
1.
2.
3.
4.
5.
6.
>15 g/kg
5-15 g/kg
.5-5 g/kg
50-500 mg/kg
5-50 mg/kg
<5 mg/kg
More than one quart
Between pint & quart
Between oz & pint
Between teaspoon & oz
Between 7 drops & tsp
A taste (< 7 drops)
Propylene glycol
Sorbic acid
Isopropanol
DDT
Hydroquinone
Dioxin
Practically non-toxic
Slightly toxic
Moderately toxic
Very Toxic
Extremely toxic
Super toxic
*Source: Toxicology: The Basic Science of Poisons, 2nd Edition, Casarret and Doull (editors), 1975
Factors Influencing Toxicity
 Duration
and
Frequency of
Exposure
 Route of Exposure
–
–
–
–
Inhalation
Contact
Ingestion
Injection
Factors Influencing Toxicity
 Substance’s
State
– Liquid
– Solid
– Gas
 Gender
 Age
 Physical
Conditioning
 Genetics
Physiological Effects
Physiology-the study
of the functions or actions of living
organisms
Irritants
-Upper Respiratory
-Lower Respiratory
-Whole Respiratory
Asphyxiants
Simple
Chemical
Systemic Poisons
Depressants
Convulsants
Respiratory Irritants
 Upper
Respiratory
Irritants
» Ammonia
» Hydrogen chloride
» Bromide
Respiratory Irritants cont.
 Lower
Respiratory
Irritants
» Acrolein
» Nitrogen Dioxide
» Phosgene
Respiratory Irritants cont.
 Whole
Respiratory
Irritants
» Chlorine
» Dimethyl Sulfide
» Ozone
Asphyxiants


Prevent the body from
receiving adequate
oxygen supply causing
Anoxia- Deficiency of
Oxygen in the Tissues
Classified into two
categories
– Simple Asphyxiates
– Chemical Asphyxiates
N2
HCN
He
H2 S
Simple Asphyxiates
 Simple Asphyxiates
– PHYSIOLOGICAL inert gases that act by
DISPLACING OXYGEN
» Nitrogen
» Carbon Dioxide
» Helium
» Methane
Chemical Asphyxiates
 Chemical Asphyxiates
– Lead to asphyxiation even in the presence of
adequate oxygen. Prevent the natural
uptake of oxygen by the blood or interfere
with the transportation of oxygen from the
lungs to the tissues
» Carbon monoxide
» Cyanides
» Hydrogen sulfide
Systemic Poisons
 Systemic
Poisons act
on specific target
organs or organ
systems.
 Some Systemic
Poisons may be
categorized as:
– Depressants
– Convulsants
Target Organs
 Skin
Eyes
 Central Nervous
System
 Kidneys
 Liver
 Reproductive System
 Gastro Intestinal
Tract

Skin
Skin, in terms of weight, is
the largest single organ of
the body
 It is composed of the
epidermis and dermis
 Skin provides
Multifunctional protection
against chemicals, heat,
UV, and bacteria

Skin
Eyes
Eyes are extremely sensitive
to chemical exposure.
 Acids, Alkalis, Solvents,
and Lacrimators pose risk
based on Chemical contact.
 Systemic poisons may
damage the eyes via the
blood system from
inhalation, ingestion, or
absorption

Central Nervous System (CNS)
The Central nervous
system (CNS)
 Affected By:

–
–
–
–
–
Solvents
Chlorinated Solvents
Lead
Mercury
Cholinesterase
Inhibitors
Liver

The liver plays a vital
role in the body:
– regulation of metabolites
– removes toxins from the
digestive system.


Hepatotoxins can be
Acute or Chronic.
The liver is the principal
organ.
Kidneys
 Kidneys
are
susceptible to toxins
because they:
– 1% of body weight
but receive ~25%
blood flow
– Have high O2
requirements based
on workload.
Kidneys cont..
– Filters 1/3 of the
plasma and reabsorbs
99% of the salt and
water. Salt
concentrations
increase
– Passive diffusion
increases upon pH
changes,
concentrating toxins
Reproductive System
 Many
chemicals
interfere with
reproductive
capabilities through
–
–
–
–
–
Sterility
Infertility
Abnormal sperm
Low sperm count
Interrupt hormone
activity
Reproductive System
Examples of chemicals effecting the Reproductive
System include:
 Male:
» Anesthetic gases
» Mercury
PCBs
» Radiation and Heat

Female:
» Parathion
DDT
» Cadmium
» Hexafluoroacetone
Toxic Effects - Teratogens
 Teratogens-
agents that
cause
developmental
defects
(congenital
malformations)
in an unborn
fetus.
Toxic Effects-Mutagens
 Mutagenic- agents that cause changes in the genetic
code, altering DNA.
Toxic Effects- Carcinogens
 Carcinogenic- agents
which stimulate cancer
in affected tissues
– Genotoxic
– Epigenetic
Fire Gases
 Carbon
Monoxide
 Hydrochloric Acid
 Sulfur Compounds
 Nitrogen Compounds
 Acid Gases
 Acetaldehyde
 Acetic Acid
 Formaldehyde
 Formic Acid
 Acrolein
Ammonia
 Hydrogen Cyanide
 Phosgene
 Hydrogen Flouride

Carbon Monoxide
Threshold Limit Value: 35ppm
Overhaul: greater than 100 ppm
Gasoline Fans: 60 + ppm
IDLH: 1200 ppm
Carbon Monoxide
•Preferential binding to hemaglobin
220 times more than oxygen
•Creates carboxyhemoglobin
Very bad stuff!
YOU WILL DIE!
Read
SOP 253.50
CO Detector Calls
Nitros and HCN
•Produces methemoglobinemia
ferrous (Fe2+) to ferric (Fe3+) state
•Poisoning of oxidative phosphorylation
cyanide ion binds to the cytochrome
a3
Both actions kill very
rapidly!
Hydrogen Cyanide
Odor threshold: .2 - 5 ppm (maybe?)
Threshold Limit Value: 10 ppm
IDLH: 50 ppm
Toxic vapor absorption: 100 ppm!
Fatal after 10 minutes: 181 ppm!!
Immediately fatal: 270 ppm!!!
End of Toxicology