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Foundation Training in Laboratory Safety. Faculty Safety Managers Stefan Hoyle & Jan de Abela-Borg. Module 2 Hazardous chemicals. Reinforce basics of risk assessment Explain how chemicals can cause harm Identify and understand control measures to minimise chemical exposure
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Foundation Training in Laboratory Safety Faculty Safety Managers Stefan Hoyle & Jan de Abela-Borg
sdfgafgafga Module 2Hazardous chemicals
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 Objectives
sdfgafgafga Routes of exposure Most serious Most readily absorbed Least likely Least readily absorbed Gases, fumes, vapours, very fine powders Corrosive liquids and those that readily cross the skin barrier Dense solids Inhalation Skin contact Ingestion
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
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
Risk factors It is also a legal requirement for suppliers to provide appropriate hazard labelling for chemicals Transport Hazard Warning Packing and Supply
sdfgafgafga 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
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:
sdfgafgafga 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])
sdfgafgafga 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
What 3 properties of a chemical would we consider when carrying out a risk assessment? • Physical properties / Quantity being used / Intrinsic hazard • Molecular weight / Intrinsic hazard / Physical properties • Flammability / Quantity being used / sell by date • Environmental impact / sell by date / reactivity with other chemicals
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
sdfgafgafga Control measures Substitute the hazardous chemical with a safer alternative Ethidium Bromide • Exclude non-essential personnel from the area • Access control systems • No write up areas in labs • Hazard zoning Prevention of exposure takes priority over control Use a safer form of the same chemical
sdfgafgafga Control measures Ventilation: use fume cupboards where necessary…... and check that they are being maintained Minimise the quantities used, stored and transported • Store hazardous chemicals • in an appropriate manner
sdfgafgafga 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?
sdfgafgafga Control measures Observe good housekeeping Ensureusers are provided with sufficient information, instruction, training and supervision Ensure that suitable emergency procedures are in place
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.
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.
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).
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
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
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
sdfgafgafga Laboratory activities that present a specific risk
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
Sources of further information Internal Safety Department website: http://www3.imperial.ac.uk/safety/guidanceandadvice/chemicalsafety http://www3.imperial.ac.uk/safety/guidanceandadvice/hazwaste External 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/