D S E A R



ans
DSEAR also requires mitigation measures to be in place in case an incident occurs. These measures include:

-           *Preventing fires and explosion from spreading;

-           *Reducing the number of people exposed to a potential incident; and

-           *Providing equipment that can safely contain or suppress an explosion or vent it to a safe place.

-           *Reducing the quantity of dangerous substances to a minimum

-           *Avoiding or minimising releases

-           *Controlling releases at source

-          *Preventing the formation of an explosive atmosphere

-          *Collecting, containing and removing any releases to a safe place (e.g. by ventilation)

-          *Avoiding ignition sources

-          *Avoiding adverse conditions (e.g. exceeding the limits of temperature or control settings) that could lead to danger

-          *Keeping incompatible substances apart.


Measures that mitigate the risk must be applied and these should likewise be consistent with the risk assessment and appropriate to the nature of the activity or operation, these should include:

-           Reducing the numbers of employees exposed

-          Providing plant which is explosion resistant

-          Providing explosion suppression or explosion relief equipment

-          Taking measures to control or minimise the spread of fires or explosions

-          Providing suitable Personal Protective Equipment (PPE)


DSEAR also specifies that the measures taken to achieve the elimination or the reduction of risk should include:

-          Design, construction and maintenance of the workplace (e.g. fire-resistance, explosion relief)

-          Design, assembly, construction, installation, provision, use and maintenance of suitable work processes, including all relevant plant, equipment, control and protection systems

-          The application of appropriate systems of work including: written instructions, permits to work and other procedural systems of organising work.


Users must ensure: -

-          Staff who handle cylinders are properly trained

-          Minimum numbers of cylinders are used and held in laboratories

-          Cylinders are secured to walls or benches with chains or proprietary clamps

-          Valves are not opened fully. Half a turn is sufficient to ensure optimum gas flow. (If fully open it becomes difficult to close in an emergency.)

-          Risk assessments are carried out to determine the potential for an explosive atmosphere when using flammable gases.

-          Adequate ventilation where flammable gases are used

-          All obvious ignition sources are removed from handling areas

-          Electrical items not in use are switched off and unplugged

-          Storage areas for flammable gases are well ventilated.

-          Cylinder valves are closed immediately when no longer needed

-          Cylinders are transported in suitable cylinder trolleys by staff trained in manual handling techniques

-          Acetylene cylinders are moved with the valve upright, or allowed to stand for at least 1 hour after moving and before use.

-          Acetylene equipment never contains copper. Acetylene reacts with silver, mercury and copper to form explosive acetylides

-          Acetylene cylinders subject to excess pressure, impact or heat must be checked for temperature rise using the back of the bare hand as acetylene becomes unstable and potentially explosive. Never move or approach a cylinder subjected to excess heat.

-          Staff are trained to fit regulators correctly

-          Flashback arrestors are fitted to fuel regulators to give flashback protection

-          Dry powder fire extinguishers are present in the workplace

-          Skin is protected from liquid propane, which freezes skin on contact.

-          Propane gas is only used with special resistant hoses (orange colour)

-          Propane is never stored underground. Ensure good ventilation at low levels

-          Propane cylinders are not exposed to excess heat

-          Propane cylinders are always transported and used upright.

-          Staff are aware hydrogen is highly flammable and ignites more easily than any other common gas.

       At high pressure it can self-ignite It burns with an almost invisible flame.

Golden rules of gas cylinder safety

-          Never tamper with, attempt to repair, or disguise damage to, a cylinder or cylinder valve – report it

-          Never transfer or “decant” gas from one cylinder to another

-          Never subject cylinders to abnormally high or low temperatures, or mechanical shocks that could damage the valve or safety device.

-          Never use cylinders as rollers or supports,

-          Never rely on the colour of the cylinder to identify the contents – the label (below valve assembly) is the only sure means of identifying the gas inside the cylinder.

-          Never apply PTFE tape, jointing compounds, lubrication or other sealing materials to valves to try to achieve a gas tight seal - if gas tight seal cannot be achieved, replace regulator or change cylinder.

-          Oils or grease are never be allowed to contaminate oxygen regulators, cylinders, pipelines, valves or associated fittings, nor should they be handled by oily or greasy hands, gloves or rags

-          Check “O” ring seals are in good condition, if not replace with approved part.

-          An “empty” cylinder is never empty - it contains gas at atmospheric pressure!

-          Before fitting regulator to cylinder - check valve for particles of dirt or water - use a clean dry cloth to remove any large deposits.

-          Fuel gases are given a smell to aid leak detection. They also need oxygen and an ignition source for combustion to occur, but once started, are self-propagating. Explosive mixtures vary according to the gas, e.g. Acetylene =2% - 82% and Propane=2% -10%.

-          Handle regulators with care. Rough treatment can damage springs, diaphragms, valve seats and valves

-          Regulators should only be used with the gas for which they were designed and labelled.

-          Using incorrect or damaged regulators on high-pressure gases is potentially hazardous.

-          Leave the pressure adjustment knob/screw fully out when the regulator is not in use

-          Regulators must be service replaced every 5 years and inspected annually by a competent person and the inspection recorded.

-          Air or nitrogen regulators must not be used with oxygen. Serious accidents have occurred when contaminated equipment has been used on oxygen systems.


Safe handling of flammable liquids Users must ensure: -

-           Minimum quantities only to be used, handled and stored

-          Risk assessments are carried out to identify and minimise the potential for an explosive atmosphere when handling and using flammable liquids (required by DSEAR) as well as their health effects (required by COSHH)

-          Adequate ventilation is provided where flammables are dispensed, used or stored

-          All obvious ignition sources are removed from storage and handling areas

-          Electrical items must be safe for use in the zone indicated, or they must be intrinsically safe for use in such areas.

-          Nylon lab coats are not used due to potential static problems

-          All flammable liquids are in suitable lidded containers and stored in clearly marked bins or cupboards away from other processes and storage areas

-           Storage areas with significant solvent vapour present are marked “EX” and all electrical equipment within the storage area is “EX” rated

-          Containers are closed, or lid put back on, immediately when not needed and returned to the proper storage bin or cupboard

-          Glass containers of flammables are carried so that they cannot be dropped or break by striking against each other or other items on trolleys – use a suitable carrier and/or plastic sleeves around individual bottles

-          Dispensing from large drums to small containers is done by trained staff

-          In laboratories, that liquids are dispensed in a fume cupboard over spillage trays and that you have a stock of inert absorbent material to mop up spills. Dispense larger quantities in a dispensary or outside

-          Solvent contaminated clothing is removed and placed in fume cupboard immediately

-          Rags and cloths used for mopping up spills are disposed of in metal containers with well fitting lids, or placed in fume cupboard, and removed from the workplace at the end of the day

-          Dry powder fire extinguishers are present in the lab.

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