Safety record is second to none CIA
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APPROXIMATELY 500 tankers carrying liquified gas operate regularly on British roads and according to Martin Trowbridge of the Chemical Industries Association, the high standard of construction of these vehicles, combined with the calibre and training of drivers has resulted in an outstanding safety record. "No member of the public has ever been killed in this country by the rupture of one of these tankers."
There are five principal bulk liquified gases moved by road by the chemical industry. These are: Chlorine: this is usually derived from the electrolysis of , salt water (brine). It is used in products such as trichlorethylene, DDT and PVC. It is also used as an intermediate for some nonchlorine chemicals including ethylene glycol (used in antifreeze) and tetraethyl lead. Chlorine has functional uses including solvents, pesticides, herbicides, plastics, water and sewage treatment.
Propylene: this is a petrochemical intermediate used in the manufacture of polypropylene and polymethane plastics, acrylic fibres and industrial solvents.
Ammonia: a major inorganic. base chemical and is also the source of nitrogen for many fertilisers and numerous industrial chemicals such as Urex.
Ethylene: this is obtained by "cracking" naphta, a product of oil distillation. It is a very important petrochemical "building block" for the manufacture of polyethylene plastics, ethyl alcohol, pvc, anti-freeze, polystyrene and polyester fibres.
Butadiene: this is a highly reactive petrochemical intermediate used to produce styrene, acrylontrile and polybutadiene synthetic rubbers. As lattices used in paints and binders for non-woven fabrics. It is also used as an intermediate in ABS plastics and nylon. The £14,000m British chemical industry is a vital supplier to all other industries, producing essential materials and components for engineering, motor vehicle manufacture, textiles, glass, farming and food, paper and printing, electronics and medicines for human and animal health.
Some six per cent of the working population are employed in the chemical industry. Chemicals account for 10 per cent of the national manufactured output and 15 per cent of the country's investment in manufacturing. .The chemical industry also contributes one-quarter of the trade surplus achieved by the manufacturing industries.
To date the British chemical industry has held its place in the top four chemical exporting nations, despite severe international competition.
It is obvious that the products of the chemical industry have to be transported to the factories that use them. Also some materials have to be transported from one chemical plant to another for further processing, as well as raw materials for more complex products.
Some of the chemicals may be hazardous — flammable, corrosive, explosive, radioactive or poisonous and ideally they are transformed and processed into innocuous products at the initial production site, so eliminating external transport. This happens in the majority of cases.
Chlorine, a poisonous gas, is produced on a large scale and can itself be converted into plastic and pvc in an adjacent plant on the same site. Harmless common salt needs to be transported to the site and harmless pvc transported away. This arrangement is not always possible and some chlorine has to be transported to its place of use.
Large-scale production of a basic chemical has to be concentrated on one site in some cases. For example, close to an oil refinery and some of its __output is required to feed other processes. It is therefore necessary to transport this portion of the product to another plant, sometimes hundreds of miles away.
Another consideration is the current interest in limiting the concentration of production and storage of hazardous materials at one very large complex. Therefore a balance has to be achieved between over-concentration of production and over-diversification, which will require more transport facilities.
As well as producing and distributing chemicals, the industries concerned — both supplier and customer — must provide safe storage facilities.
It is important to determine what is meant by "hazardous." This word is used to mean chemicals which could be dangerous if wrongly or carelessly handled. Some chemicals are dangerous in small concentrations, especially to those who may be exposed to them over a long period of time. In moving chemicals, however, the commonest risk is exposure to large quantities resulting from the escape of a product from its container.
Many simple chemical products such as paint, medicines and aerosols require careful handling. This is particularly relevant when they are moved in bulk and obviously safety comes first in the choice of the methods of distribution of chemicals.
Gases are probably the most difficult to transport, because they are too bulky at normal atmospheric pressures. To transport them in commercial quantities they are compressed, liquified under pressure, refrigerated to a liquid or solid or dissolved under pressure in a solvent.
The resultant product is transported in a container designed to prevent any undue hazard in the event of a road accident.
Carbon dioxide is trans-. ported in three ways, each appropriate to a particular end use: a compressed gas in cylinders for medical pur poses; as solid "dry ice" for us as a refrigerant, and as a ga dissolved in water unde pressure in soda syphons.
The method of transporta tion is determined mainly b commercial factors. Pipelin transfers are only suitable i the case of very large quani ities over a long period of timE Sea and air transport ar obviously required for over seas shipments.
Some manufacturers hay access by road, some by ra and some both. In many case more than one method c transportation is employed t convey a product from it place of manufacture to it place of use.
Every method of transpor tion has its own very strict se of regulations, every chemicz has its own transportatio, requirements which includ packaging, labelling an storage and in many cases ar reinforced by codes of practic drawn up by the CIA and it individual member firms.
The CIA would be only to pleased to see the Governmen adopt their code as the basis c legislation because over th years it has proved to work.