© imperial college londonpage 1 foundation training in biological safety
TRANSCRIPT
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Routes of exposure
Inhalation
Skin contact
Ingestion
Gases, fumes, vapours, very fine powders
Corrosive liquids and those that readily cross the skin barrier
Dense solids
Most serious
Least likely
Most readilyabsorbed
Least readilyabsorbed
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Risk factors
Intrinsic hazard associated with the substance
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
Severity of hazard
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Risk factorsRisk 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
Currently 60+ Risk Phrases listed under
Chemical (Hazard Information and
Packaging for Supply) Regulations
(CHIP)
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Risk factorsIt is also a legal requirement for suppliers to provide appropriate hazard labelling for chemicals
How many types of hazard label are there?
Packing and Supply Hazard Warning Transport
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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 factorsWorkplace 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 > medium BP > low BP Solids: pellets / granules > crystalline > dusty
Quantity
e.g. small > medium > high (<1g [ml]) (1 – 100g [ml]) (>100g [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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Control measures
Substitute the hazardous chemical with a safer alternative
EthidiumBromide
Prevention of exposure takes priority over control
Use a safer form of the same chemical
Exclude non-essential personnel from the area
Access control systems
No write up areas in labs
Hazard zoning
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Control measuresMinimise the quantities used, stored and transported
Store hazardous chemicalsin an appropriate manner
Ventilation:
use fume cupboardswhere necessary…...and check that theyare being maintained
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Wear appropriatePersonal ProtectiveEquipment (PPE)
Dispose of chemical waste properly: sink or specialist waste contractor?
Transport hazardous
chemicals
using appropriate
containment methods
Control measures
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Control measures
Observegoodhousekeeping
Ensure users are provided with sufficient information, instruction, training and supervision
Ensure that suitable emergency procedures are in place
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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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Laboratory activities that present a specific risk
Activity Control measuresWeighing 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 / eyesChemical splash to hand / armChemical splash on laboratory coatChemical injected beneath skin by needleExposure by inhalation (sometimes including eye irritation)Numerous reports of ‘solvent’ smellsAllergic reaction attributed to chemical contactAcute asthma attackSpillage onto bench / floorChemical in mouth – rare
….and a skin blister arising from self treatment of wart on foot with liquid nitrogen!
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Some other legislation relating to chemicals
Dangerous Substances and Explosive Atmospheres Regulations (DSEAR)
Home Office Drug Precursor Legislation
Chemical Weapons Act
Anti-Terrorism Crime and Security Act
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Sources of further information
Internal
External
Safety Department website:http://www3.imperial.ac.uk/safety/guidanceandadvice/chemicalsafety
http://www3.imperial.ac.uk/safety/guidanceandadvice/hazwaste
HSE:http://www.hse.gov.uk/index.htm
Sigma Aldrich:http://www.sigmaaldrich.com/Area_of_Interest/Europe_Home/UK.html
Wikipedia:http://en.wikipedia.org/
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1.Is the substance flammable?No. Flammability is usually indicated in Sections 3 (Hazards Identification) and 15 (Regulatory Information)
2. What is the UK Workplace Exposure Limit for this substance?2ppm (Section 8 - Exposure Controls and Personal Protection). OEL is the Occupational Exposure Limit
3. How would you dispose of 5 Litres waste chloroform?Via specialist waste contractor organised by Estates Helpdesk – (Section 13, Disposal Considerations).
4. How would you store the substance in the laboratory?In a solvent cabinet with appropriate signage and preferably equipped with a spillage tray. Section 7, Handling and Storage offers little useful guidance in this instance.
5. Would you need to wear a respirator for routinely handling laboratory quantities of this substance?If the substance is handled properly in a functional, well maintained fume cupboard, this should be sufficient to ensure that respiratory exposure is minimised and kept below the 2ppm WEL. Respiratory protection would probably only be envisaged for dealing with a large spill outside a fume cupboard.
Workshop Exercise 1
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Workshop Exercise 2
SCENARIO:
You enter a laboratory first thing in the morning and notice an odour. You recognise that two specimen jars on the benchtop have cracked and spilled 4% formaldehyde onto the benchtop and an area of the floor. There is still evidence of liquid present.
WHAT DO YOU DO NEXT?
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MODEL ANSWER
1. Leave the room again immediately.
2. Close the door and secure if possible.
3. If the door cannot be secured, attract the attention of a colleague to stand by the door or prepare some temporary warning signage to affix to the door.
4. Report the incident to your Group Safety Adviser / DSO.
5. Nobody should enter the room until the airborne concentration of formaldehyde is established. This can be determined using a portable formaldemeter – several meters are kept by the Safety Department and others are held locally.
6. Once the readings have been established there are two options:
a. A member of staff can enter wearing suitable respiratory protective equipment and clean the spillage up using a polymerising agent.
b. The room can be left vacant until the formaldhyde has evaporated completely. The length of time that this takes will be dependent upon the quantity spilt and the ventilation standards within the laboratory.
7. Complete a dangerous occurrence report in accordance with established College procedures.