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HAZARDOUS SUBSTANCES. HSNO Flammable Classes 3 and 4. Flammable Liquids - Class 3. 3.1 Liquids category A, B, C, & D 3.2 Liquid Desensitised explosive category A, B, & C. Class 3.1 Flammable Liquids. Class 3.1A - very high hazard
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HAZARDOUS SUBSTANCES HSNO Flammable Classes 3 and 4
Flammable Liquids - Class 3 • 3.1 Liquids • category A, B, C, & D • 3.2 Liquid Desensitised explosive • category A, B, & C
Class 3.1 Flammable Liquids • Class 3.1A - very high hazard • flash point of less than 230C and initial boiling point <350C • e.g: ether • Class 3.1B - high hazard • flash point of less than 230C and initial boiling point >350C • e.g.: acetone
Class 3.1 Flammable Liquids • Class 3.1C - medium hazard • Flash point greater or equal to 230C, but less than 600C • Class 3.1D - low hazard • Flash point greater than 600C, but less than or equal to 930C
Class 3.2 • 3.2A - liquid desensitised explosives: high hazard • 3.2B - liquid desensitised explosives: medium hazard • 3.2C - liquid desensitised explosives: low hazard
Class 3 - Safe handling • Containers of 3.1A shall only be opened or decanted in fume cupboards • Bottles of ready to use reagents stored on benches or shelves should not exceed • 1 litre for category A substances • 2.5 litres for category B substances • The opening and pouring of all flammable liquids should be carried out in a fume cupboard
Class 3 - Safe handling • Open containers for as short a time as possible - not exceeding 10 minutes, with the following max. volumes • 1.5L decanted volume of any flammable liquid with a flash point less than or equal to 100C above ambient temperature, or; • 5L decanted volume of any flammable liquid with a flash point greater than 100C above ambient temperature
Class 3 - safe handling • Spill - absorb using sand or substance suitable for absorption of the liquid • Emergency plans • Extinguish any ignition sources - vapour heavier than air and will sink down to lowest level
Class 3 - safe handling • Storage cabinets - no ignition sources, secondary containment • No more than 100 litres per cabinet, max. 20 litres per container • Secondary containment to hold 50% • Refrigerators used to store flammable substances must be spark proof and labelled • external thermostats and light fittings removed
Class 3 - safe handling • Storage of substances category A not to exceed 5 litres e.g.: ether (trackable) • 20 litres maximum for all other categories • If in laboratory, must be an approved container or storage cabinet. • DG Store (certified) for bulk storage
Flammable Vapours • Less than 0.5ml of residual ethanol in a 2.5 L Winchester can produce a saturated air/ethanol vapour mixture. Refilling a 2.5 L Winchester which has held ethanol at 190C will release 2.5 litres of a saturated ethanol vapour/air mixture. This can result in over 42 litres of flammable vapour!
4.1.1 Readily combustible 4.1.2 Self reactive 4.1.3 Solid Desensitised explosive 4.2 Spontaneously combustible 4.3 Dangerous when wet Class 4 - Flammable, Solids
Class 4 - Flammable Solids • 4.1.1A - readily combustible solids and solids that may cause fire through friction - medium hazard • 4.1.1B - readily combustible solids and solids that may cause fire through friction - low hazard
Class 4 - Flammable Solids • 4.1.2A - self reactive substances, type A • 4.1.2 (B - G) - self-reactive substances • 4.1.3A - Solid desensitised explosives: high hazard • 4.1.3B - Solid desensitised explosives: medium hazard • 4.1.3C - Solid desensitised explosives: low hazard
Picric Acid • Classes 4.1.3A, 6.1B, 6.3B, 6.5B, 8.3A, 9.1D, 9.3B • Class 1.1D but controls only apply to large quantities (25 - 50kg +) • toxic, explosive, corrosive and ecotoxic
Class 4 - Flammable Solids • 4.2A - spontaneously combustible substances:pyrophoric substances:high hazard e.g.: phosphorus (yellow/white, dry or in solution) • 4.2B - spontaneously combustible substances: self-heating substances: medium hazard e.g.: potassium hydrosulphite • 4.2C - spontaneously combustible substances: self-heating: low hazard
Class 4 - Flammable Solids • 4.3A - solids that emit flammable gas when in contact with water: high hazard • Calcium Carbide - emits acetylene gas • 4.3B - solids that emit flammable gas when in contact with water: medium hazard • 4.3C - solids that emit flammable gas when in contact with water: low hazard
Flammables requiring tracking • 3.1A (ether) • 3.2A • 4.1.2A • 4.1.2B • 4.1.3A (picric acid) • 4.2A • 4.3A