Occupational Safety and Health Programs are an important component of organizations. Occupational hazards are numerous and expensive to the organizations. There are laws that safeguard the employee’s physical and emotional well-being. As per Herzberg’s theory, working condition which assures safety is a factor of motivation in organizations. A cost-oriented manager understands the importance of avoiding accidents in his organization. Costs associated with leave due to illness, disability compensations and alternate skilled employee placement are huge and have a negative impact on employee morale. Organizations should ensure a safe work environment, which protects employees from physical hazards and unhealthy situations.
This is important because employees are the Human Resources of an organization who contribute towards organizational success. In the U.K, the Control of Substances Hazardous to Health (COSHH) regulations and Control of Major Accident Hazards Regulations (COMAH) have stipulated strict safety norms for every industry in UK. As the Safety manager of the new production facility of the industrial gas production company producing Ammonia and Oxygen, it is important to evaluate the safety procedures based on the plant operations and chemical nature of these two highly reactive gases. Oxygen is highly reactive releasing enormous energy in the process of combining with other reactive chemicals. Oxygen is produced as a gas or liquid by numerous methods like cryogenic distillation and adsorption technologies.
The new production facility utilizes cryogenic distillation process for industrial oxygen production. Ammonia is another hyper reactive gas that is produced by the combination of Hydrogen and Nitrogen gases at high pressure and temperature in the presence of a catalyst. A pressure of around 200 atmospheric pressure and a temperature of about 500oC, give a 20 percent yield of ammonia with minimized maintenance costs and safety concerns during operation of the plant. Although Nitrogen is inert, Hydrogen ignites readily with oxygen to form an explosive gas called oxy-hydrogen. Further, Hydrogen has a high combustion energy release, which will spell disaster in case of accidents. Thus, it is extremely important to strictly adhere to the industrial safety norms to safeguard the working population and the population in the vicinity of the production site. The Control of Major Accident Hazards Regulations 1999 (COMAH) came into force from 1 April 1999 and are amended by the Control of Major Accident Hazards (Amendment) Regulations 2005 from 30 June 2005 as per the Council Directive 96/82/EC known as the Seveso II Directive, as amended by Directive 2003/105/EC.This has replaced the Control of Industrial Major Accident Hazards Regulations 1984 (CIMAH) in UK.
Although COMAH applies mainly to the chemical industry, some storage activities, explosives and nuclear sites, and other industries where threshold quantities of dangerous substances identified in the Regulations are used also comes under its stipulations. Statutory Instruments1999, No.743, The Control of Major Accident Hazards Regulations 1999 clearly defines that “every operator shall take all measures necessary to prevent major accidents and limit their consequences to persons and the environment.”(Part 2 – general duty). Under the heading, Major accident prevention policy, the regulation stipulates that “every operator shall prepare and keep a document setting out his policy with respect to the prevention of major accidents referred to as a “major accident prevention policy document”, designed to guarantee a high level of protection for persons and the environment by appropriate means, structures and management procedures.” The major accident prevention policy document will contain sufficient particulars to demonstrate that the operator has established a safety management system, which takes account of the principles of COMAH.
The COMAH also stipulates that the operator of the establishment shall send to the competent authority a notification containing the safety measures, the nature or physical form of the dangerous substances, the processes employing them, and any other information notified to the competent authority in respect of the establishment. COMAH also stipulates that the operator should also send a Safety report prior to commencement of production and start production after examination and certification from the competent authority. The operator is also required to submit a Review and revision of safety report at least every 5 years to ensure absolute safety. Part 4 of the Statutory Instruments1999, No.743 of COMAH further stipulates that every operator of an establishment shall prepare an On-site emergency plan in consultation with the persons employed in the establishment; the Agency, the emergency services, the health authority for the area where the establishment is situated and the local authority in whose area the establishment is located.
The Operator is also required to furnish a Review and testing of emergency plans at least once in three years which facilitates a review and necessary revisions the plan, testing the plan to take reasonable steps to arrange for the emergency services to participate and inculcate changes occurring in the emergency services concerned, new technical knowledge, and knowledge concerning the response to major accidents. Part 5 of COMAH lays down the Provision of information to the public, which says that the establishment shall ensure that persons who are likely to be in an area are supplied, without their having to request it, with the information on safety measures at the establishment and on the requisite behaviour in the event of a major accident at the establishment. Thus, commitment to COMAH regulations will automatically ensure a safe operation of the plant and hence, strict adherence to these regulations discussed is the primary objective to achieve the goal of absolute safety of the plant operation.
An Evaluation of Industrial Safety:
In 2004, 5,703 fatalities have been reported of which 1004 were due to contact with equipments, 815 because of falls, 459 due to exposure to harmful substances and 159 due to fire and explosions. There are three basic causes of workplace accidents.
1. Chance occurrence, 2.Unsafe conditions and 3. Unsafe employee acts. Since chance occurrence is beyond human control, the other two are to be focused.
Unsafe working conditions cause accidents. Unsafe working conditions include poorly guarded equipment, defective equipment, hazardous operational procedure, lack of illumination and ventilation. About one third of the industrial accidents have been found to occur around forklift trucks, wheelbarrows, lifting areas, around transmission machinery like gears, pulleys and flywheels. Ladders, walkways, stairs and scaffolds are common sites of accidents.
Failure, Modes & Effects Analysis:
Most of the accidents in the oxygen and other gas production plants are due various technical reasons. This includes non-provision of skid mount design of the various equipments. This not only dangerous but also delays re-installation and is costly. Use of old designs primarily composed of gas welding is prone to leaks. Copper soldering and hand brazing used in Europe thirty years back is no longer recommended. These designs have the risk of oil-carry over and hence, explosions. These old designs make use of Oxygen compressors with water lubrication, Chinese molecular sieves with poor life and have a soldered circular design. The trays are hand fitted and fixed by soldering .The provision of loose length of pipes and fully solder welded air separation units between the lower condenser and upper column is also a serious cause of leaks and subsequent explosions. In such a design, the entire column is cut open for maintenance or to rectify leaks. Use of non-coded pressure vessels and open type compressors also lead to explosions.
Oil grease or similar substances should not be allowed to come into contact with compressed oxygen or liquid oxygen. Contact of such substances with oxygen results in an explosion. Thus it is also necessary to ensure that the clothing of the workers is free from contaminations of oxygen before approaching a naked flame. Those working in an area of possible oxygen concentration, such as near an oxygen vent or a liquid oxygen spillage, or in a trench where oxygen seepage and concentration might occur, should ensure that their clothing is free of any oil grease or similar substances. It is absolutely essential that the clothes be dried at least for 15 minutes before approaching a flame after contact with such substances. Apart from this, all the oxygen fittings valves and parts should be thoroughly washed with clean Tricolor Ethylene or
carbon tetra chloride (CTC) before installation. Petrol, kerosene or other
hydrocarbon solvents should never be used for this purpose. All tubing and lines valves to be used in oxygen production should be thoroughly degreased and blown out with clean oil-free compressed air or Nitrogen before being placed in service. It is important not to allow the release of flammable gases like Hydrogen in the vicinity of the plant air intake. It is equally important to rectify any oil leak within the plant surrounding without delay. Oil spillage should be cleaned up immediately using carbon Tetra Chloride. Oxygen valves, regulators, gauges or fittings should not be lubricated at all.
Electric conduits should never be fastened to the plant or its pipelines and
oxygen should not be used as a substitute for compressed air. Even a spark present in an atmosphere of oxygen will immediately burst into flame. It is important not fill any container or pipeline with oxygen unless it has been thoroughly degreased .The valve s should be opened slowly When discharging liquid oxygen or rich liquid from drains, to avoid the possibility of being splashed. In particular, it should be ensured that liquid does not run into shoes or gloves. Any such Contact with liquid oxygen rich liquid will cause whiteness and numbness of the skin. The affected parts must be batched at once in cold water and requires immediate medical attention. It is dangerous to breathe
cold oxygen vapor. A deep breath of vapor results in frostbitten lungs with resultant serious illness and permanent disability or death. It is recommended to check Compressor and Expander lubricating oil consumption for any excessive consumption and the cause rectified. The use of a flame for welding or cutting in the immediate vicinity of the Air Separation Plant or oxygen piping should be permitted only when the plant has been shut down and de frosted and when the oxygen content of the air within the equipment concerned does not exceed the atmospheric normal of 21%. Fluid at high pressure moving at a high velocity is dangerous. Hence use of a face shield or chemical safety goggles is highly recommended. A new workgroup on hydrogen safety has been launched with its first meeting held on 6 March 1998.launched by the National Hydrogen Association, the group proposes to set a standard, not a technical report, for safe hydrogen use which will complement the U.S./Canadian joint effort “Sourcebook on Hydrogen Applications.” The standard will also be of international scope rather than focused on U.S. and Canadian practices.
The other preventive measures include employment of skid-mounted design where all the equipments and machineries are mounted on single skid ready for installation. The air separation unit should be made up of cryogenic grade leak-proof stainless steel with argon welding. The liquid oxygen pump should have a stainless steel head with a oil-free design. Molecular sieve battery with L/D ratio that prevents fluidization has a long life and safety history. Press fitted argon welded trays are preferred over hand fitted solder welded trays to ensure 99.6 percent purity and safety. The gas and airlines should be fabricated and not be loose. Coded pressure vessel design ensures safety from vessel explosions. A common method for the production of nitrogen and oxygen is the liquefaction of air. When such a process is involved, air is compressed, expanded and cooled via the Joule-Thomson effect, and then re-compressed and expanded again and re-cooled until air is liquefied. Since nitrogen boils at a lower temperature than oxygen, the nitrogen can be distilled off the liquid air and then recompressed and re-liquefied. Since the Joule-Thompson effect depends on the expanding air doing some work, a turbine type expander is employed. In such a process a seal gas system ensures that the lubricating oil does not contaminate the airlines which if unchecked will invariably lead to explosion.
In normal operations the air Compressor Inlet stage separator drains and moisture separator drains are to be opened and closed, 30 minutes, to let out condensed moisture after recording readings in a prescribed Log Sheet. Molecular Sieve Drier Heating and cooling cycles are to be taken care regularly. It is better to keep the rare gas vent valve R-22 slightly open to allow non-condensed rare gases to escape from Lower Column. After starting the plant, the air pressure should be brought down slowly to about 40 Kgs./cm2, by further opening V3. Oxygen Purity should be checked by drawing sample gas from R-27 & R-28 every half an hour. Presence of hydrocarbons like acetylene in the atmospheric air or in air compressor oil can cause explosions.
Thus Liquid Oxygen and liquid air should be drained in order to avoid accumulation of Acetylene every 8 hours. Acetylene analysis should also be carried out in every shift. If present the plant should be stopped and defrosted. In case of warming up of the plant, throttling V3 valve brings down expansion cam position and increases cooling. Cylinder filling should be checked periodically for gas leaks. Water level should be always at half level in the evaporation cooler. A new technique to detect localized corrosion in steel and other metals that help prevent serious safety problems in industrial plants is currently in use in UK. Corrosion affects the structural durability of metals and alloys used in pipe work, tanks and filters. Localized corrosion always lead to pitting resulting in the cracking and eventual fracture that cause leakages causing explosion. Scanning techniques capable of providing useful information on local corrosion is in use in central Europe, the Far East and North America.
Hazard Management: Apart from unsafe workplace conditions, the job itself, the work schedule and the psychological climate of the workplace also plays a role in work related accidents. In Ford’s Boiler explosion case that the worker’s failed to close the valve that connects the furnace and hence, there was a blast killing 6 people. Thus, it is evident that unsafe employee acts also cause industrial accidents. For years, Psychologists assumed that some people are simply accident prone based on situations. But, recent studies have shown multiple causes. Thus, occupational accidents can be prevented by reducing unsafe conditions and unsafe employee acts. Reducing unsafe conditions is the first component of prevention of occupational hazards. Removal of physical hazards by job designs, identifying hazards by checklist procedures helps reduce unsafe conditions. The remedial measures can be simple removal of debris on ladder or scaffold, floor coatings, mats and lighting, supply of slip- resistant footwear, cut resistant gloves, protective clothing or designing job properly with hazard watch supervisors and job rotation. The best way to reduce unsafe acts is by screening employees case history for such acts of negligence and Safety training programs.
The fact that the law demands a safe work environment triggers a ‘Safety Program’ in every Organization. Organizations with Safety Programs implement COMAH AND COSSH standards by various activities.
Safety Awareness Promotion: Most organizations have a Safety Awareness Programme that includes lectures, commercially produced films, Video shows and pamphlets, which teach employees safe work procedures. They also create an awareness on safety hazards that occur on account of the non-compliance of Safety norms.
Proactive Safety Training Program: Safety training programs include First aid , Accident prevention techniques, Hazardous materials awareness and Emergency procedures training.
Most of the programs train the employees about the use of emergency first aid equipment and Safety equipment. Employee’s ideas and experience offer valuable contributions in Safety programs. Montgomery, Pa., encourages employees to serve on safety committees (http://www.occupationalhazards.com/safety_zones/52/article.php?id=14209).
Enforcing Safety Rules:
Safety rules and regulations are communicated through supervisors, bulletin boards, employee handbooks and signs attached to machines/equipments. Regular safety meetings refer to the use of safety devices, proper work procedures, good housekeeping procedures, complying with accident-injury reporting, safety clothing and avoiding carelessness.
It is true that discipline makes employees to work safely. But it is voluntary willingness from the employee that will last for a long period. All the employee safety programs aim at this employee involvement in the safety aspects of the organization.
COSSH requirements demand that organizations with eleven or more employees should maintain records of work related occupational hazards. A recordable case is an injury or illness that results in death, days away from duty, restricted work or transfer to another job due to disability, or medical treatment beyond first aid (Bohlander, 2004).
Safety Managers should plan on the basis that they may not be able to rely on external agencies for support in the event of an accident. They should also have well rehearsed evacuation and management plans which can be implemented in the event of a fire. The key factors are Planning. Vigilance and good house keeping. It is the duty of the Safety Management Team in every plant to carry out a fire risk inspection and assessment to ensure that they understand the plant, its layout, the corridors, gangways and exit doors, which form the means of escape. The functioning of the fire detection system and alarm should be periodically checked. There should be a regular test of the fire evacuation drill in all premises. Safety Managers should implement a robust fire risk management regime, which will test the fire alarm and public address systems every week. The regime will regularly, not less than twice daily, inspect corridors, gangways, stairs, exit doors and ensure that these are maintained clear of obstructions. The team will also check for the build-up of combustible materials. Hot work is any process or use of any equipment, which will produce, sparks or flame e.g. metal disc cutters, grinders or blowlamp. Managers should take steps to the use of such equipment during periods of plant shutdown. Safety Managers should check emergency fire safety equipments like firing blanket, fire extinguishers and hosing reels. Staff should be trained of the proper procedure for using a fire extinguisher. In the event of a fire and explosion the first step in hazard management is to sound the alarm and organize the evacuation. Safety Managers should review their muster and roll call arrangements to ensure in the event of an emergency evacuation that everyone has escaped from the plant.
Recommendations and conclusions based on COMAH and COSHH guidelines:
Gas production facilities often expose the e workers to various chemicals, which harm them on chronic and acute exposure. In a circular numbered 71/2002, The Health and safety Executive (HSE) published revised COSHH (the control of substances hazardous to Health) regulations. This COSHH 2002 regulations came into force from 21 November for hazardous substances and includes control measures for hazardous substances. COSHH 2002 spells out much more clearly on risk assessment than COSHH 1999. The risk assessment includes the properties of the chemical, health effects, the exposure limits, preventive and control measures, health surveillance, monitoring and other additional information needed.
The EH40 ,on occupation Exposure limits, published by HSE books, EH54 on Assessment of exposure to fume from welding and allied and processes, EH55 on the control of exposure to fume from welding, provide good data required for risk assessment like occupational exposure limit (OEL).The supplement to the control of substance hazardous to Health Regulations 2002 addresses the respiratory hazards in discussion. According to these regulations, every employer should ensure the prevention of employee’s exposure or adequately control where in not practicable reasons to prevent. Personal protective equipment (PPE) must be used only as a last resort, in addition to control measures. When RPE (Respiratory Equipment) is used to control exposure, the correct equipment and training are to be ensured. Appendix I of the supplement gives guidelines on Respiratory protective Equipment selection and training.
Health surveillance under COSHH Regulations 2002, Requires Health surveillance programmes where the exposure of the employee to a substance hazardous to health is such that identifiable disease or adverse health affect may be related to the exposure; There is a reasonable likelihood that the disease or effect may occur under the particular conditions of the work and there are valid techniques for detecting indications of the disease or effect .(Regulation 11). COSHH stipulates that prevention and adequate control of the exposure should be done either by stopping using the sensitiser (Chemical) and replacing it by less harmful substance or segregating the workplace or provide local exhaust Ventilation or by use of Respiratory protective instrument (RPE). That is to say that only where prevention of exposure is not possible , adequately controlled exposure is recommended (www.COSHH.com).Adequate control means Application of the eight principles of good practice as in shedule 2a of COSHH, not exceeding workplace exposure limit (WEL).
Safety starts with management commitment. For example, Dupont’s accident rate is lower than the other chemical industries as a whole. Its good safety record is due to the organizational commitment to safety. Each morning at the Dupont Polyester and Nylon plant, the directors and his assistants meet at 8.45 to review the past 24 hours. The first matter for discussion is safety and not production. Only after examination of reports of accidents and near misses, they look into production for the day (Dessler, 2003).In U.S.A., Safety program at a Missouri, ABB Business Services plant resulted in 80% reduction of accident cases and $560,000 recorded as profit. Compensation costs for accidents have soared sky high. It should be recognized that effective cost management on compensations starts before the occupational accidents and not after.
A cost-oriented manager understands the importance of avoiding accidents in his organization. Costs associated with leave due to illness, disability compensations and alternate skilled employee placement are huge and have a negative impact on employee morale.75 million working days are lost because of on-job-hazards. $50 billion are given as compensation for injuries and deaths in organizations. $50 billion is spent on indirect costs like replacement, training and so on (Bohlander, 2004).