4.2 Storage, handling and transport of dangerous substances

Question 1

The primary legislation applying to the control of substances that can cause fires and explosions in the workplace is

Answer 1

the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR).

Question 2

Dangerous substances may be liquids, gases, vapours or dusts and include: 3

Answer 2

 Substances or preparations classified as explosive, oxidising, extremely flammable, highly flammable, or flammable under the current CHIP Regulations, or CLP Regulation.  Any kind of dust that when spread in air to form a cloud (i.e. form an explosive atmosphere), can explode.  Any other substances, or mixtures of substances which, because of their physical properties and the way in which they are present in the workplace, create a risk to safety from fires and explosions, but which may not be covered by CHIP. For example high flashpoint liquids present in the workplace at elevated temperatures.

Question 3

Overview of the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR)

Answer 3

Regulation 5: Risk assessment Regulation 6: Elimination or reduction of risks from dangerous substances Regulation 7: Places where explosive atmospheres may occur Regulation 8: Arrangements to deal with accidents, incidents and emergencies Regulation 9: Information, instruction and training Regulation 10: Identification of hazardous contents of containers and pipes Regulation 11: Duty of co-ordination

Question 4

Hazard identification (determination of the presence of dangerous substances) requires consideration of the following three variables:

Answer 4

(1) The substance or preparation is classified under the Chemicals (Hazard Information and Packaging for Supply) Regulations (CHIP) as: explosive, oxidising, extremely flammable, highly flammable or flammable. (2) The physical and chemical properties of the substance or preparation, and the work processes involved, creates a potential for fire, explosion or similar energetic (energy releasing) event. (3) The work activity involves the creation or handling of potentially combustible or explosive dusts.

Question 5

factors that should be taken into account when undertaking a dangerous substances risk assessment.

Answer 5

The hazardous properties of the substance Supplier safety information The circumstances of the work Particular activities, which may present a high level of riskThe likely presence of explosive atmospheres and the need for hazardous area classificationSize of release Temperature and pressure VentilationExtent of zones

Question 6

Bulk storage of flammable liquids Bulk storage refers to tanks with a capacity in excess of

Answer 6

1000 litres.

Question 7

Control measures for the storage of flammable liquids can be summarised by the acronym

Answer 7

VICESVentilationIgnition sources (control of)ContainmentExchange (substitution)Separation

Question 8

The storage of flammable liquids in IBCs in warehouses poses particular problems, notably: 3

Answer 8

 They are prone to early failure in a fire, allowing leaked contents to feed the fire.  They degrade over time, and so are prone to leaks when used for long term storage.  They are generally made of cheap, non-conductive plastic, so when non-conducting flammable contents splash around in transit the surface becomes electrostatically charged.

Question 9

Outline the key safety features of a facility that is to be used for the storage of highly flammable solvents in 200 litre drums 10 marks

Answer 9

Key safety features include:  bunding to contain spills, including a facility to collect and dispose of spillages  the building to be erected on an impermeable base with an adequate separation distance from other buildings and constructed of fire resistant materials with a light weight roof or blast panels  a facility for the segregation of materials  adequate access and egress including a ramp to facilitate the handling of drums  the provision of high/low ventilation and of sprinklers/ fire extinguishers to be used in the event of an emergency  the clearance of vegetation round the storage area  security features such as the provision of locks and warning signs.

Question 10

A company intends to build a flammable solvent distribution facility as part of its chemical manufacturing premises. The facility will include three 40,000 litre storage tanks that are pump filled via pipelines from batch reactors. The storage tanks supply an outdoor road tanker filling system as well as a small container filling facility located inside a warehouse. Outline the design features that should be adopted to prevent or minimise leakage and spills from the proposed installation. 10 marks

Answer 10

Design features to be adopted include:  Ensuring the pipework is of all weld construction with the minimum number of flanges with a suitably corrosion resistant material used in its construction.  The pipework should be routed along a containment trench or should be double skinned and further protected by robust barriers at vulnerable points near to roads or railways.  The storage tanks should be in a bunded area capable of containing 110% of the contents of all three tanks with the base and walls of the bund being impervious and free from breaches for services.  The tanks should be fitted with high level detectors interlocked with a pump cut out with the pumps themselves being situated within bunds with interceptor facility. The road tanker stands should be located in an intercepted shallow bund with snap shut connections on the tanker filling lines.  In the warehouse the small keg filling lance should be fitted with a dead man’s handle together with a supply cut out when the expected weight is registered on a load cell.  Finally all valves in the installation should be designed to prevent leaks such as for example with a double mechanical seal with means for preventing them being left in a partially open state.

Question 11

There are various approaches to unloading road tankers: 3

Answer 11

 Product transfer by gravity - if the storage tank is located at a lower level than the tanker.  Product transfer using a pump - care must be taken to avoid the implosion of the tanker.  Product transfer under positive air pressure - pneumatic or ‘blowing’, provided by the truck compressor or at the customer facility.

Question 12

Precautions should be taken against spillage due to vehicles being moved with the hoses still connected or arms still in place. This can be done by

Answer 12

providing barriers across the tanker stance, brake interlocks on the vehicle or breakaway couplings on the hose connections.

Question 13

Precautions against static electricity should be provided, including: 3

Answer 13

 an earthing connection for the vehicle  electrically conducting hoses  elimination of splash filling, by ensuring that the fill pipe in a top loading operation reaches to the bottom of the tank or tanker, for example.

Question 14

A TREMcard is

Answer 14

a four page document that is held in the cab of a dangerous goods delivery vehicle. A TREMcard (transport emergency card) gives detailed written instructions to the driver in case a dangerous goods load is involved in a road traffic accident (RTA).

Question 15

The TREMCard contains the following information: 9

Answer 15

 Load description  Nature of the danger  Personal protective equipment  Intervention equipment  General action by the driver  Additional / specific actions by the driver  Driver actions in case of fire  First aid  Supplementary information for the emergency services.

Question 16

For road tank transport operations and carriage in bulk internal to the UK there are two forms of placarding/plate marking permitted.

Answer 16

(1) GB registered road and rail vehicles on domestic journeys must display the Emergency Action (Hazchem) Code. (2) All other vehicles must display the Hazard Identification Number (HIN) (Kemler code).

Question 17

Interpreting the Emergency Action Code (EAC) The first character of the EAC determines the

Answer 17

fire-fighting extinguishing medium. 1 = coarse water spray 2 = fine water spray 3 = normal foam, i.e. protein based foam that is not alcohol resistant 4 = dry agent (water must not be allowed to come into contact with the substance)

Question 18

The second character of the EAC indicates

Answer 18

appropriate personal protection. For the letters S, T, Y or Z, normal fire-fighting clothing to the appropriate BS EN’s is appropriate,

Question 19

UN Dangerous Substance Classes

Answer 19

1 Explosives 2 Gases 3 Flammable liquid 4 Flammable solids 5 Oxidising substances 6 Toxic substances 7 Radioactive material 8 Corrosive substances 9 Miscellaneous dangerous goods

Question 20

Exam question As part of its water treatment system, a manufacturer is to install a plant suitable for the reception and storage of sulphuric acid and caustic soda, both of which will be delivered in bulk tankers. Both of these substances are highly corrosive and can react together violently. Outline the safety provisions required for: (a) the design 10 (b) the operation 6 (c) the maintenance of the proposed storage facility. 4 marks

Answer 20

(a) Under the design issues, answers were expected to include:  the need for the storage tanks and pipe work to be constructed of suitable chemical resistant material with organic materials such as wood being avoided in or near to the acid installation  the delivery inlets for each substance to have different connector types to prevent connection being made to the wrong tank  the positioning of the storage tanks in separate bunds with the bunds being capable of holding the entire contents of the tanks plus 10% with protection being provided against weather conditions such as trace heating on caustic soda lines  the pipe work to be colour coded to British Standards  the fitting of level indicators and high level alarms to prevent overfilling  interlocked with a cut-out pump on high level  the provision of good vehicle access including a hard standing for tankers with facilities for spill containment and drench showers  the provision of a good standard of lighting and measures to avoid tankers  driving off when still connected to the delivery system. (b) Operational issues should have included:  the introduction of a safe system of work agreed with the material suppliers requiring a two man operation  emergency procedures to deal with spillages and to protect against sewer or drain contamination  the provision and maintenance of a contingency supply of neutralising and absorbent materials and water  providing training for the personnel involved including tanker drivers in the risks associated with the operation and the control measures to be followed  the provision of personal protective equipment such as chemical suits, chemical resistant gloves and full face protection.

Question 21

The DGSA has three main duties:

Answer 21

(1) Monitoring compliance with rules governing transport of dangerous goods. (2) Advising their business on the transport of dangerous goods. (3) Preparing an annual report to management on the business’ activities in the transport of dangerous goods.

Question 22

A road haulage company intends to transport significant quantities of bulk flammable materials in tank containers. They are advised that they require a ‘Dangerous Goods Safety Adviser’. (a) Outline the criteria under which a ‘Dangerous Goods Safety Adviser’ must be appointed. 4 (b) Outline the particular duties of a ‘Dangerous Goods Safety Adviser’. 6 (c) Outline the procedures and practices that a ‘Dangerous Goods Safety Adviser’ should be monitoring in the event that the tender is successful. 10 marks

Answer 22

(a) Many involved in the business of carriage of dangerous goods should appoint a ‘Dangerous Goods Safety Adviser’. Exemptions are for those who carry small or limited loads and also for those where the carriage of dangerous goods is not the main activity, although they may still carry dangerous goods as part of their business (constructions companies taking dangerous goods to and from site, for example). Dangerous Goods Safety Advisers must obtain a vocational training certificate, having completed relevant training and passed an exam. The VTC is valid for 5 years. (b) Duties of a DGSA include:  advising their business on the transport of dangerous goods  monitor compliance with rules governing the transport of dangerous goods  preparing an annual report to management about the business activities involving the transport of dangerous goods  monitoring procedures and safety measures  investigating and compiling reports on incidents, accidents and emergencies. (c) Procedures and practices to be monitored by the DGSA include:  Vehicle purchasing procedures (ensuring new vehicles are suitable for contents to be transported).  Dangerous goods are properly identified and the correct placards are in place.  Selection of suitable, competent sub-contractors.  Maintaining and inspecting equipment to ensure it is in good, safe working order.  Ensuring that all necessary documents (Tremcard) and emergency equipment is in situ.  Employee training and record keeping.  Planning of on-going training to maintain risk awareness.  Provision of detailed operational procedures and instructions.  Accident investigation arrangements / implementation of measures to avoid recurrence.  Loading / unloading of dangerous goods.  Emergency procedures.  Security plans.  Document control and retention.