Safety Matters
Real – Life Scenarios
Accidents Happen
April 2006
Safety Workshop TCD
Chemical Hygiene:
•Skin contact
•Accidental stabbing, cuts, other skin breaks, entry
into deep tissues, bloodstream
•Local Toxicity / effect (dermatitis, cracking of skin)
•Penetration through skin - dimethyl sulfoxide, alcohols,
benzene, carbon disufide pass through epidermis and act
as a “vehicle”.
• Inhalation
Splash, dust particles, gas,
caustic vapours
‘Queen’s University Belfast,
Pharmacy Lab – evacuated for 24
hours following Br spill – poisonous,
deep oily liquid causing burns’
• Ingestion (object-to-mouth)
Contamination, deposition
on surfaces, foods,
smoking, nail-biting
Protective Clothing
Hands – cuts, sores
forearm – hair folicles
eyes - toluene
‘Graduate student severly burnt from waist down – dropped a beaker of
ether onto a heated surface which caused a flash explosion beneath a
chemical fumehood – hospitalised for 2 weeks’
Chemistry Professor Karen E. Wetterhahn, Dartmouth College
Died by poisoning resulting from by a few drops of dimethylmercury.
Dimethylmercury, a colourless liquid, was used as a
reference standard for NMR experiments.
During sample preparation dimethylmercury accidentally
penetrated a protective glove.
The accident occurred in August of 1996.
Six months later symptoms of the mercury poisoning
were detected by which time the effects were
irreversible.
Professor Wetterhahn rapidly went into a coma and died
in June 1997.
Protective Gloves
“During the investigation of this accident, it was learned the MSDS
prepared for both the manufacturer and supplier of the dimethylmercury
sample in question had erroneous information on the proper gloves to be
worn when handling this extremely toxic compound".
This is a tragic example of what can happen when MSDS information is
incorrect.
As a result of her tragedy, safety standards for gloves and other
protective equipment were revised, and a movement began to eliminate
production and use of dimethylmercury.
At the time of her diagnosis and before she lapsed into a vegetative
state, Prof. Wetterhahn asked that her case be made known to
others in the hope of preventing a similar tragedy.
Applied Occupational and Environmental Hygiene Volume 16(2): 233–236, 2001
Laboratory Environment
The scene of an accident
University of Kentucky 1997
Chemical wastes accidentally mixed resulting in a fire and explosion
Choloroform added to the waste bottle resulted in Brown Fumes.
The bottle was capped and the student and walked away.
A minute or two later it exploded
The explosion blew glass shrapnel across the laboratory and was
immediately followed by a fire that engulfed the lab giving-off thick
black smoke
Accident University of Kentucky 1997
The Debri
•Burn marks and soot above the hood
•Overhead fluorescent lights shattered by flying
debris.
•Glass fragments from the explosion travelled up to
10 metres
•Some embedded up to 20 mm deep in the
fumehood insulation
Remember: The Fume Hood is not a Storage Area
This accident occurred in a hood that contained many stored chemicals as
well as waste.
Sonicator Causes Explosion
Univeristy of Ohio
What Happened:
A graduate student used a sonicator to agitate
a mixture of zinc, ethyl ether, and
bromoethylacetate (a lachrymator) in a
sealed round-bottom flask.
The sonicator caused a rapid rise in
temperature which sent the contents of the
flask into the fume hood.
A graduate, was exposed to the lachrymator
vapours, causing intense irritation to the
eyes and lungs.
What can be done to prevent this from occurring again?
Sonicators use sound waves to agitate mixtures...this can cause rapid heating
and localized points of increased pressure. They should not be used with sealed
flasks or with flammable liquids...especially low-boiling solvents (such as ether).
The sonicator was in the fume hood, but it was placed in the front just behind
the sash. The equipment should be set as far back as possible...away from the
sash.
The student was not wearing eye protection.
Working In Fume hoods
1. If a hood is being used to store particular
chemicals then run the reaction in a different
hood.
2. Keep the Sash at the appropriate Level.
When not in use, the sash should be closed.
When you are using the hood, the sash should be no higher than
14 inches. If higher than, then fumes are escaping into the room
and hence into your lungs.
3. Keep all work >15 cm behind sash opening
4. CLEAN UP! Remove all equipment and chemicals that you
brought into the hood. Place all reagents back in their proper
storage place. Dispose of all waste.
Working In Fume hoods
5. Unattended Reactions
All unattended reactions must be known
about - labelled with a description of the
reagents/hazards and contact details
In 1997 a fire destroyed a research laboratory at the University of
Washington, estimated damage $500,000 and wiping out several
research projects.
The fire, started by an unattended hotplate, began in a laboratory on
the top story of five-story research facility.
Fire department officials said the fire was contained largely in one
room but was intensely hot. No one was injured.
Safe Science May 1997
Specific Procedures
Solvent Wastes
Storage – chemical turn-around
Distillation – destroying the evidence
Sodium – in the distillation of solvents
Fire at UT Austin Chemistry Laboratory
On October 19, 1996, a fire broke out in an organic-synthetic chemistry lab.
The fire began when a post-doctoral researcher was disposing of some sodium
metal. The researcher was in the process of deactivating the sodium by exposing
the metal to alcohol. A small amount of residual metal, came into contact with
water as he poured the material down the sink creating a small flame.
The fire grew into a blaze when the researcher accidentally broke a container of
acetone into the sink in an attempt to remove the container from the sink area
where it was being stored.
The principal investigator characterized the laboratory as a total loss (0.5 million
dollars of damage). Many research records and notes for current projects were
destroyed, as well as a lot of archival material going back 10 to 15 years. In
addition, two adjacent laboratories were heavily damaged by smoke and water.
The Austin Fire Department primarily blamed the incident on poor housekeeping
of chemicals. Chemical inventories for the laboratory were kept electronically
and the responding fire fighters had no information on what chemicals were
involved in the fire. As a result, unlabelled containers and improperly stored
flammable chemicals were encountered during the fire fighting effort.
Real-life Events have Highlighted :
Chemical storage, turn-around
- Keeping accurate risk assessment
Personnel saftey equipment
-Wear appropriate protection
Correct fumehood use
-Close the sash, keep clear, keep equipment to the back
Chemical waste disposal
-Do not mix wastes –
metal residues, caustic residues, chlorinated solvents