Foundation Training in Laboratory Safety

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Foundation Training in Laboratory Safety

• Faculty Safety Managers
• Stefan Hoyle Jan de Abela-Borg

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Module 2Hazardous chemicals
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Objectives

• Reinforce basics of risk assessment
• Explain how chemicals can cause harm
• Identify and understand control measures to
  minimise chemical exposure
• Describe how fume cupboards work and how to use
  them

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Routes of exposure
Gases, fumes, vapours, very fine
powders Corrosive liquids and those that
readily cross the skin barrier Dense solids
Inhalation Skin contact Ingestion
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Risk factors
Intrinsic hazard associated with the substance
Severity of hazard
Low health hazard Substances designated as
irritant (those that affect the skin and
sometimes the eyes)
Medium health hazard Substances designated as
corrosive, irritant (particularly by the
inhalation route) or harmful (particularly by the
inhalation route)
High health hazard Substances designated as
toxic, very toxic, carcinogenic, mutagenic and
those that may impair fertility or harm the
unborn child
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Risk factors

• Risk Phrases
• All hazardous substances are allocated Risk
  Phrases that describe the particular hazard(s)
  associated with that substance
• Risk Phrases can be found on the Material Safety
  Data Sheet (MSDS) supplied with the substance.
• It is a legal requirement for suppliers to
  provide safety information in the form of an MSDS

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Risk factors
It is also a legal requirement for suppliers to
provide appropriate hazard labelling for chemicals
Transport
Hazard Warning
Packing and Supply
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Risk factors
Suppliers must also identify and label chemicals
that present a safety risk as opposed to a health
risk..
.and those that have an environmental impact
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Risks factors

• Workplace Exposure Limits (WELs)
• In addition to Risk Phrases, some hazardous
  substances have occupational exposure limits set
  under COSHH in order to protect the health of the
  worker
• These are airborne concentrations, averaged over
  a time period, that must not be exceeded
• Information on WELs can also be found on the MSDS
  for the substance

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Risk factors
Physical properties
Dictate the potential to become airborne
e.g. Liquids high boiling point gt
medium BP gt low BP Solids pellets
/ granules gt crystalline gt dusty
Quantity
e.g. small gt medium
gt high (lt1g ml) (1
100g ml) (gt100g ml)
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Risk factors
By multiplying values for INTRINSIC HAZARD x
PHYSICAL PROPERTIES x QUANTITY .we can
arrive at a figure that gives an indication of
overall risk factor
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What 3 properties of a chemical would we
consider when carrying out a risk assessment?

1. Physical properties / Quantity being used /
   Intrinsic hazard
2. Molecular weight / Intrinsic hazard / Physical
   properties
3. Flammability / Quantity being used / sell by date
4. Environmental impact / sell by date / reactivity
   with other chemicals

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What is the correct sequence (hierarchy) of
implementing controls to minimise chemical
exposure?

• Elimination (substitution) / Segregation / PPE
  (personal protective equipment)
• PPE / administrative controls / segregation
• Risk assessment / PPE / Permit to work system
• Administrative controls / PPE / physical controls
• Elimination / PPE / storage considerations

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Control measures
Prevention of exposure takes priority over control
Use a safer form of the same chemical
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Control measures
Minimise the quantities used, stored and
transported
Store hazardous chemicals in an appropriate
manner
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Control measures
Transport hazardous chemicals using
appropriate containment methods
Wear appropriate Personal Protective Equipment
(PPE)
Dispose of chemical waste properly Departmental
waste routes and local arrangements, specialist
waste contractor?
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Control measures

Observe good housekeeping
Ensure users are provided with sufficient
information, instruction, training and supervision
Ensure that suitable emergency procedures are in
place
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Fume Hoods

• The fume cupboard is a major means of
  controlling your exposure to chemicals and other
  airborne hazardous materials.  A moving curtain
  of air (at 0.5 0.1 ms-1) being drawn past the
  operator, through the opening, over the work,
  then up the exhaust stack reduces your exposure. 
  A fume cupboard used properly provides adequate
  protection.  However, use a fume cupboard
  incorrectly and it may result in dangerous
  material escaping from the cupboard.

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Fume Hoods Before Use

• Ensure the fume cupboard is operational and there
  is an airflow.  Listen and feel for air movement
  - this should be obvious with the sash in its
  lowest position.
• Check for obvious surface contamination.  Clean
  if necessary, to avoid adverse reactions with the
  chemicals in use.
• Ensure that you have enough space to conduct your
  work safely.
• Position equipment, apparatus, and materials in
  the centre and back of the cupboard to minimise
  disturbance to airflow.  Where practical, place
  everything within the cupboard before starting
  operations.

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Fume Hoods During Use

• Avoid sudden rapid movements in front of the
  cupboard.  These can cause turbulence that may
  draw the airborne hazardous material out of the
  cupboard.
• Use the sash position to your advantage -
• Fully open - access for setting up
  equipment,
• Partially open, at safe working height -
  when handling material inside the cupboard while
  experiment is in progress.
• Lowered - when the process is in operation
  and intervention is no longer required.
• Accidental spills of chemicals should be cleaned
  up immediately (i.e. as soon as it is safe to do
  so).

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Fume Hoods Emergency procedures

• If the fume hood breaks down during a hazardous
  procedure
• Make the experiment safe
• Turn off ignition sources
• Close reagent containers
• Inform your demonstrator/supervisor immediately

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Which of the following should you not use a fume
cupboard for?

• Weighing fine powders
• Decanting 2.5 litres of methanol to smaller
  bottles
• Homogenisation of human tissue
• Distilling flammable solvents

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No horseplay in the lab !!!!!!!!!!!!!!!!!
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Carrying out and recording the COSHH risk
assessment
STEP 1 Identify the hazards STEP 2 Identify
who may be at risk STEP 3 Establish control
measures STEP 4 Record the assessment STEP
5 Review the assessment
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Chemistry Department Risk Assessment forms
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Laboratory activities that present a specific risk
Activity Control measures
Weighing Consider using fume cupboard or other benchtop enclosure such as weighing station
Pipetting Consider using fume cupboard and or drip trays dispose of pipette tips properly use good pipetting technique clean and maintain automatic pipettes
Shaking / mixing Consider using fume cupboard in conjunction with PPE
Centrifugation Ensure compatibility of tubes with chemicals balance tubes PPE clean-up procedures and training
Syringe filtering Consider alternative methods use Luer lock fittings select right pore size dilute sample FC and PPE
Use of sharps Eliminate wherever possible select right tool for job wear appropriate PPE ensure safe disposal
Elevated temperature Lower temperature if possible use fume cupboard cover or partially cover reduce surface area
High pressure equipment Consider location of equipment in conjunction with PPE
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Accidents do happen

• Chemical splash to face / eyes
• Chemical splash to hand / arm
• Chemical splash on laboratory coat
• Chemical injected beneath skin by needle
• Exposure by inhalation (sometimes including eye
  irritation)
• Numerous reports of solvent smells
• Allergic reaction attributed to chemical contact
• Acute asthma attack
• Spillage onto bench / floor
• Chemical in mouth rare
• .and a skin blister arising from self treatment
  of wart on foot with liquid nitrogen!
• so report them

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Sources of further information
Internal
Safety Department website http//www3.imperial.ac
.uk/safety/guidanceandadvice/chemicalsafety http/
/www3.imperial.ac.uk/safety/guidanceandadvice/hazw
aste
External
HSE http//www.hse.gov.uk/index.htm Sigma
Aldrich http//www.sigmaaldrich.com/Area_of_Inter
est/Europe_Home/UK.html Wikipedia http//en.wiki
pedia.org/