Small tubes of petroleum ether stored in a freezer evaporated and accumulated to a concentration above the lower explosive limit. A spark from the freezer's internal components ignited the vapors, causing $500,000 in damage. Similarly, lab personnel ignored warnings that too much hydrogen had entered an anaerobic hood and became flammable, resulting in an explosion that injured four people when the gas encountered an ignition source. The document provides guidance on hazard communication, material safety data sheets, chemical storage, personal protective equipment, chemical spill response, and general safety rules to prevent such incidents.

1. Stewart Sampson
Safety Services Nova Scotia

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It can happen!!
Hazard Communication
MSDS
Understanding Hazards
Chemical Storage
Personal Protective Equipment (PPE)
Chemical Spill Response
Waste Disposal
General Safety Rules

3. 
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Small tubes of petroleum ether were stored in
an ordinary domestic freezer.
The tubes were not sealed well and the PE
evaporated to a concentration exceeded the
lower explosive limit, about 1.0%
◦ Flash point of PE is -50 °C
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A spark from an internal component of the
freezer caused the PE to ignite
$500 000 in damage
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What caused this?
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4. 
Anaerobic hood — an oxygen-free
chamber used for working with bacteria
that can't survive in oxygen
Lab personnel ignored a "warning
system" designed to tell researchers
when too much hydrogen enters the
chamber and becomes flammable
An explosion resulted when the gas
came into contact with an ignition
source
Four people injured
One critically
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What caused this?
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5. 
Hazard Communication
◦ Allows workers to know the hazards and identities
of the chemicals they are exposed to while working.
Describes measures they can take to protect
themselves.
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Hazards are communicated by:
◦ Labels
◦ Material Safety Data Sheets (MSDS)
◦ Education and Training

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MSDS – a document prepared by the chemical
manufacturer that describes the:
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physical and chemical properties
physical and health hazards
routes of exposure
precautions for safe handling and use
emergency and first-aid procedures
control measures

7. What are the WHMIS Hazard Classes?
Compressed Gas
Flammable and Combustible Material
Oxidizing Material
Poisonous and Infectious Material
Corrosive Material
Dangerously Reactive Material

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Toxicity
◦ the ability of a chemical to cause harm
◦ Like “Hazard” in general safety terms
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Risk
◦ likelihood a material will cause harm under the
conditions of use
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With proper handling, even highly toxic
chemicals can be used safely
Less toxic chemicals can be extremely
hazardous if handled improperly

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Inhalation – breathing (e.g., powders, fumes)
Absorption – skin or mucus membranes
Ingestion – entry through mouth
Injection – through skin by foreign body
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Acute Exposure (short term): eye irritation,
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nausea, dizziness, skin rash, burns, headache
Chronic Exposure (long term): long-term
illness

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In 2008, Sangji was working with a bottle of t-butyl
lithium dissolved in pentane
While using a syringe to withdraw a quantity of the
reagent, it seems she accidentally pulled the plunger
all the way out, introducing air and creating a flash
fire
◦ “Sangji was not familiar enough with the material and
delivery means to be doing the experiment on her own”
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Sangji was wearing nitrile gloves, safety glasses
rather than goggles, and a synthetic sweater with no
lab coat
When the fire ignited the gloves and the sweater, she
sustained second and third degree burns over 40 per
cent of her body and was immediately hospitalized
She died 19 days later

12. 
eliminate the hazard;
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substitute other materials, processes, or equipment;
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engineering controls;
◦ Not using high shelves
◦ Toluene for benzene
◦ Fume hoods, engineered sharps
◦ Eye Wash
 Eye wash station; Disposable Eye Wash
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systems that increase awareness of potential hazards;
administrative controls
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Personal protective equipment
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◦ training and procedures, instructions, scheduling;
◦ Gloves, lab coats/uniforms, eye protection, safety shoes,
respirators, face shields
◦ Gloves
 Use proper size
 Use proper glove material

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Professor of chemistry at Dartmouth College
specialized in toxic metal exposure
A few drops of dimethylmercury was accidentally
spilled onto her hands
◦ Protected only by latex glove
◦ Tests later showed that DMM can rapidly permeate latex
gloves and enter the skin within 15 seconds
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Single exposure to DMM had raised her blood
mercury level to 80 times the toxic threshold
◦ Delayed neurotoxic effects caused her to be hospitalized
after 5 months, and she died 10 months after the
accident
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She was 48

16. White = OK
Red = Incompatible

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Do not respond beyond your training level!
Stop, think – Is this a Major spill?
◦ No
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Remove contaminated clothing
Use proper PPE
Contain spill
Notify workers in your area
Seek MSDS for advice
Notify supervisor / security
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Rescue
Avoid the chemical
Find the MSDS
Telephone for help
◦ Yes

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Stop, think – Can I extinguish this fire?
◦ Yes
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Extinguish open flames
Turn off gas / electricity
Notify workers in your area
Ventilate work area
Notify supervisor / security
◦ No
 Evacuate area immediately and pull alarm
 Call emergency number

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Minimize waste in the first place
Do not pour chemical waste down the drain
Know your chemical classification
Use flame resistant container with label
Don’t leave funnel on top of waste container
Use proper mercury disposal (broken
thermometers)
Call for pick up

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Store chemicals in their original containers
Always wear appropriate safety gear and work
in a controlled environment
Always dispose of chemicals properly
Use care in handling contaminated glassware
or needles
Always dispose of chemicals properly

21. 
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Don’t buy chemicals you do not need
Don’t eat, drink, smoke, chew gum or apply
cosmetics near chemicals
Don’t mouth pipette
Don’t use unlabeled containers
Know chemical properties as well as toxicity

22. 
Any final questions? Thoughts?