Process Safety and Loss Prevention assignment



M.Sc Process Safety and Loss Prevention

1. a) ASSESSMENT AND CONCLUSIONS ABOUT EXISTING RISK (DSEAR): Dangerous Substances and Explosive Atmospheres Regulation (DSEAR). The main aim of this regulation is to protect and improve health and safety of workers at risk from explosive atmospheres. It has been implemented within UK Health and Safety legislation as the Dangerous Substances and Explosive Atmospheres Regulation (DSEAR) 2002 which also includes the process safety aspects of the Chemical Agents Directive (Directive 98/24/EC). Under the Directive and its various national implementations Companies need to demonstrate that they have, by means of a risk assessment, both organizational and technical measure in place to effectively control explosion risk. Organizational measures will include:-

  • Permit to work systems.
  • Operator training with regard to explosion protection.
  • Written instructions for operators in hazardous areas.
  • Emergency evacuation procedures.

Technical measures will include:-

  • Explosion relief systems to include bursting panels and isolation devices.
  • Control of static electricity.
  • Suitable dust extraction and collection.
  • Proper selection of electrical and non-electrical equipment.
  • Fires and explosions create harmful physical effects such as thermal radiations, overpressure effects and oxygen depletion, and the same effects are caused by other energetic events such as runaway exothermic reactions involving chemicals or decomposition of unstable substances such as peroxides. These events are also covered by DSEAR.

    The following examples illustrate the type of activities covered by DSEAR:

    • storage of petrol as a fuel for automobiles and machinery;
    • handling and storage of waste dusts in a range of chemical industries;
    • handling and storage of flammable wastes such as fuel oils;
    • work that could release naturally occurring flammable substances such as methane in coalmines or at landfill sites;
    • use of flammable solvents in laboratories;
    • storage and display of flammable goods, such as paints, in shops;
    • filling, storing and handling aerosols with flammable propellants such as LPG;
    • transporting flammable substances in containers around a workplace;
    • deliveries from road tankers, such as petrol and bulk powders;
    • chemical manufacturing, processing and warehousing;
    • The petrochemical industry, both onshore and offshore.
    • DSEAR applies to workplaces, like industrial and commercial premises, land-based and offshore installations, mines and quarries, construction sites, vehicles and vessels, etc., and the places include common parts of shared buildings, private roads and paths on industrial estates ,etc., in which dangerous substances are present, may be reused.

    Here we are using toluene substance in the process which is toxic and it is also risk to people's safety from fires and explosions which is similar to 'thermal runway' from chemical reactions. Dangerous substances may also be in form of liquids, gases, vapors. Toluene is flammable liquid so appropriate measures have to be taken to ensure safety in workplace.

    Here DSEAR places responsibilities on employers to assess the risk and thereafter try to reduce/eliminate the risk from dangerous substances. It follows:

    Assessing risk:

    To assess the risk there should be an identification and careful examination of:

    • The dangerous substances in the workplace;
    • The ways in which toxic substances and work activities could harm people.

    The employers must take necessary steps and measures to eliminate the risk from toxic substances that might occur in the workplace If there are risks to safety then employers must consider what else needs to be done to copious fully with the requirements of DSEAR. The employer must record the significant findings of the risk assessment.

    Preventing or controlling risks

    Employers must put control measures in place to eliminate risks from dangerous substances, or reduce them as far as is reasonably practicable.employers must take measures to control risks and reduce the severity (mitigate) the effects of any fire or explosion In case if it is difficult to completely eliminate the risk factor, so as a result the dangerous substances are avoided and substituted with another substance or using a different work process. This is called substitution in the Regulations.

    This could be explained by giving an example like substituting the substance of low flashpoint substance with that of high flashpoint substance. But still in some cases it may not be possible to replace the dangerous substance at all, like it is practically impossible to replace petrol with another substance at a filling station.

    Control measures

    Where the risk cannot be eliminated, DSEAR requires control measures to be applied in the following priority order:

    • minimize the quantity of dangerous substances, used and released;
    • avoiding the formation of a dangerous atmosphere;
    • necessary ventilation and airflow should be maintained to collect contain and remove any waste;
    • avoid ignition sources and also fallow the limits of temperature or control settings;
    • Keep contrary substances apart.


    In addition to the control measures DSEAR requires employers to put mitigation measures in place. The measures framed should be consistent with the risk assessment and appropriate to the nature of the activity or operation and include:

    • reducing the number of employees exposed to the risk by taking advanced sophisticated measures ;
    • providing plant that is explosion resistant ;
    • providing explosion suppression or explosion relief equipment;
    • taking measures to control or minimize the spread of fires or explosions;
    • Providing suitable personal protective gears for the employees.

    Preparing emergency plans and procedures

    To ensure better preparedness during emergencies appropriate arrangements and measures have to be taken. This can be done by conducting regular safety drills and also tutoring the employees about the communication and early warning systems in accordance with the risks. In addition to this workers must also be educated about the necessary tasks that have to be carried out in case of emergencies.

    The information in the emergency plans and procedures must be made available to the emergency services to allow them to develop their own plans if necessary.

    Providing information, instruction and training for employees

    Employees must be provided with necessary information, instructions and training. This includes:

    • the hazardous substances present in the workplace and the risks they present including access to any relevant safety data sheets and information on any other legislation that applies to the dangerous substance;
    • the findings of the risk assessment and the control measures put in place as a result (including their purpose and how to follow and use them);
    • Emergency procedures in emergency situations.
    • All the relevant information, instruction and procedures must be made available to the employees

    References for 1.a):-

    • Don peacock (HSE)(2009). Introduction to the DSEAR regulation. [Lecture handout].From Design for safe handling of industrial chemicals, held on 12 October, university of Sheffield.
    • Fire and explosion: Further information and guidance. [online].last accessed 12 November 2009 at:
    • Statutory Instrument 2002 No. 2776. The dangerous Substances and Explosive Atmospheres Regulations 2002 [online]. Last accessed 12 November 2009 at:


    To prevent danger from flammable or explosive the employers are require to follow the Dangerous Substances and Explosive Atmosphere Regulations. the dangerous substances must be substituted as far as possible, this can be achieved either by preventing or dangerous atmosphere forming or by controlling all ignition sources in the industry. common dangerous substances include degreasing solvents paints, varnishes, extremely flammable liquids, flammable gases, oxidizer and explosive dust.

    The sources of explosive atmosphere depends on the activity like storage of flammable substances and processes involving flammable substances Storage can be in number ways like drums of flammable substances, packages of combustible dust and bulk storage tanks. Flammable substances involved in the process like drums of flammable liquids, number of process vessels and flammable gas involved in number of batches.

    The flammable atmosphere caused due to the process can be controlled by the following ways:

    • Minimizing the usage quantity of explosive substances
    • Avoiding release of flammable gases into the environment
    • Avoiding chemical reaction hazards by segregation of contrary flammable substances
    • The ignition probability depends on the zoning , the ease with which the material might be ignited this depends upon the proportion of flammable, highly flammable and extremely flammable substances.

    The severity of explosive atmosphere depends on the number of people expose to it. To decrease the severity certain mitigation measures or taken this include explosion resistant plant, explosion separation like use of fire extinguishers, explosion relief, arrangements to deal with emergency incidence. Certain emergency plans must be taken to reduce the effect of accidents like who may be affected in the worst case, on sight and off sight plans.

    Toluene is clear liquid which is not soluble in water. Since the plant under study uses toluene, the employers are most likely to be exposed to toluene. Toluene evaporates into air and which vapors can be breathed in [1].


    As per under the General safety measures in" The Dangerous Substances and Explosive Atmospheres Regulations 2002" one has to ensure that the workplace is designed, constructed and maintained so as to reduce risk. Designing, constructing, assembling, installing, providing and using suitable work processes so as to reduce risk.

    Maintaining work processes in an efficient state, proper working order and in good condition.
    Ensuring that the equipment and protective systems meets the following requirements-

    (a) Equipment and protective systems must be maintained in a safe state of operation independently of the rest of the plant in the event of power failure; so as to minimize the risk of spread of additional risk.

    (b) means for manual override must be possible, operated by employees competent to do so, for shutting down equipment and protective systems incorporated within automatic processes which deviate from the intended operating conditions, provided that the provision or use of such means does not compromise safety;
    (c) on operation of emergency shutdown, accumulated energy must be dissipated as quickly and as safely as possible or isolated so that it no longer constitutes a hazard; and
    (d) necessary measures must be taken to prevent confusion between connecting devices.[2.1],[2.2]

    • Inert gas blankets should be set up before flammable materials are introduced, and should be maintained throughout the process whenever flammable atmospheres can occur.
    • Pressure which we are applying to the reactor that pressure should not be exceeded design pressure.
    • Regular observation should be needed on pressure relief valves during the process.
    • Proper ventilation is required.
    • Cooling jacket should be maintained because the exothermic reaction takes place during the process.
    • Here we are operating batch reaction process, so once process completed before doing second batch reaction process we should clean reactor neatly.


    For safety operations in chemical reactor necessary assessment of the hazards has to take care of. The details of the entire safety process involving measurements and important safety data on the material used in the particular respective operation [3].

    References 1.b):-

    [1]DSEAR Risk Assessments-J Gould,

    [2.1] Statutory Instrument 2002 No. 2776. The Dangerous Substances and Explosive Atmospheres Regulations 2002 [online]. Last accessed 12 November 2009 at:

    [2.2] Statutory Instrument 2005 No. 1541. The Regulatory Reform (Fire Safety) order 2005 [online]. Last accessed on 12 November 2009 at:

    [3]Paul N.Sharratt. (1997). Handbook of batch process design.[Online]. Suffolk. Last accessed on 16 November 2009 at:


    COSHH:(Control of Substances Hazardous to Health) this is the regulation made under the health and safety department COSHH act which is introduced with a view to "protecting people against risks hazardous to health, If exposure happens at the workplace. This act introduced in 1974. The main aim of this act action should be taken immediately.

    COSHH regulations are applicable where the hazardous substances causing health problems present at the work place. The COSHH regulations envelop not simply laboratory work with substances hazardous to health, every work activity which is including substances hazardous to health for example cleaning, catering, workshop procedures and buildings and maintenance normally referred to by a trade (or) brand name, encloses substances hazardous to health and their use is subject to the COSHH regulation

    1 Duties under the COSHH regulations:

    1.1. Before starting of any work using a substance hazardous to health a suitable and sufficient assessment is made of the risks to health created by that work and the steps of that need to be taken to meet the requirement of the COSHH regulations;

    1.2. Copies of COSHH assessment should be stored at work place for reference, either electronically, or in hardcopy format;

    1.3. maintain appropriate measures, measures should be controlled and maintained the equipment efficient working order and arrange good repair

    1.4. Sufficient arrangements made for the maintenance, examination at intervals specified in the regulations, of engineering controls and respiratory protective equipment;

    1.5.coduct training session about the risks presented at work and precautions to be taken, keep giving information and instruction to the employees, students and visitors;

    1.6. Formulate full and proper use of any control measures, personal protective equipment, provided to prevent exposure, report immediately any fault discovered in control measures.

    2. General procedure on COSHH assessment:

    COSHH assessment necessary when there is no work involving a substance hazardous to health may be undertaken until a suitable and sufficient COSHH assessment has been carried out. Substances classified as toxic, very toxic, harmful, corrosive or irritant, which causing hazardous to health

    Process assessment-where a process involves number of substances but to be convenient to prepare a single assessment covering the whole process, but we have to give hazardous information about all the hazardous substances, and to assess which substance give rise to the greatest risk. In multi-step processes, it may be possible to vary the precautions taken at different stages as the risk change.

    Some novel and unidentified compounds found during the process, in such cases these compounds are treated as toxic, except in those cases where more serious hazards can reasonably be expected.

    Review of assessments-in addition, all assessments should be reviewed at regular intervals to check that they are still suitable to the circumstances of the work being carried out.

    The break time should not be greater than five years for uses involving a low degree of risk. For higher risk procedures, reviews should be undertaken more frequently.

    3. Steps in carrying out a COSHH assessment:

    3.1. Assessment of risk-the risk to health is the possibility that the substance will cause harm in the actual circumstances of use. The hazards associated with a substance is not a risk assessment, the main aim to reach the degree of risk to health involved in the particular planned use of a hazardous substance, leaving aside, at this stage, the effects of any precautionary measures. The degree of risk may be different by different ways and this will influence the precautions needed to control exposure.


    3.2. During the process we should take some short of precautions for existing risks. The exposure substances hazardous to health will be prevented. The simple precautions which is enclosed by good laboratory practice' will sufficient in emergency cases, such as spill ageor the failure of containment, precautions in formation should be given at work area.

    3.3. people who are working around reactor in which process toluene is involved, they should be aware of toluene how it is harmful to our health, it requires relatively low hazard rating, it requires handle with care, particularly because of its volatility.

    References for 2.a):-


    Recommendations are made on how to control hazardous substances at the plant so that they do not cause ill health to the workers. These regulations are made based on COSHH regulations. When more people are involved in the plant, decision making in controlling hazardous substances becomes complex.

    Due to the absence of effective measures workers are made ill due to the exposure to toxic substances. The common diseases include asthma, cancer and other skin diseases. Unfortunately it is quite common for the workers to have developed an illness or disease once they are into such industries. These are commonly called as Industrial Illness or Industrial Disease. It is the responsibility of the employers to ensure the safety of their workers. If a job involves working in a hazardous environment, it is the employer who should ensure that their workers have minimal contact or replace harmful substances with less harmful ones.

    Some of the common substances which are harmful are:-

    • Lung diseases are caused due to poisonous fume-laden air.
    • Working in wet condition for a continuous period can cause dermatitis.
    • Benzene can cause leukemia.

    Many other products used at work can also be harmful, like paint, lubricant, and detergent harmful chemicals. Some of the ways of preventing diseases are recommended below

    Chemical handlers should be ware about the transfer of chemicals, because chemicals can be swallowed from their hands to their mouths by eating or smoking. This can be avoided by ensuring common cleanliness practices like washing hands first and also usage of hand gloves.

    Boiling point of toluene is 110.6C and vapor pressure is 22mmHg/20C.due to the availability toluene can be easily procured .since that chemical is hazardous in nature toxicity can occur from unintentional or deliberate inhalation of fumes by ingestion or transdermal absorption. Toluene abuse has widened among children and adolescents.

    Irritation to the eyes can be caused due to exposure to chemical vapors, gases and dusts. This can be prevented by using eye wares, masks and regular eye care.

    Needle stick and butchery injuries are rare but can cause infections due to skin puncture if not disposed of safely.

    To assess the risk to their employees, employers are requiring following certain COSHH regulations to prevent or control those risks. Risks are different for different tasks like minute harmful substances might be breathed in or might get on to the skin, while following unsafe disposal system. But during leakage of large amounts of harmful substances leads to greater exposure and greater risk. Based on the task and risk factors employers need to take measures and also employees must record the assessment taken to identify the risk.

    Few examples of control measures regarding exposure is mentioned below:

    • The process of cleaning with solvent on drag, control equipments like rag holder or else a small bin with lid can be provided for used rags. These bins must be disposed safely.
    • To perform the above task certain way of working has to be adapted like avoiding skin contact and reducing solvent vapor from used rags [1].

    The COSHH regulation ensures to prevent or control exposure to toxic substances that are hazardous in nature. This can be achieved by using control equipments, controlling procedures and worker behavior. By reducing the number of employees in the hazardous environment employees cannot make any improvement to exposure control.

    Respiratory protective equipment can be used in places where air cannot be cleaned. General ventilation, extraction systems such as local exhaust ventilation can be employed. Other control equipments like spillage capture, decontamination personal protective equipment.

    Control through ways of working includes training, emergency procedures, decontamination for task such as maintenance. Maintenance includes testing all control measures on equipments and behavior to ensure proper working and also keep records of examinations, test and repairs to equipment periodically. This helps to notice any variation in equipment deterioration [2].

    Reference for 2.b):-

    [1] Working with substances hazardous to health. Published 06/09, by Health and Safety executive. [Online]. Last accessed on 12 November 2009 at:

    [2] Control measures to prevent or limit exposure to hazardous substances. Published 06/09, by Health and Safety executive. [Online]. Last accessed on 12 November 2009 at:


    Every nation has got its own safety and legislative acts regarding the environment, with legislation relevant to process safety starting with government act, like explosives and transportation act. But presently there are numerous agencies, acts and regulations related to process safety. There are several agencies and law firms that have been established across the world to keep process plant risks and safety under observation. Among these the most notable agencies are the environmental protection agency (EPA) which was established under the national environmental act of 1969 and also the occupational safety and health administration (OSHA) was established. Both of these two organizations are involved in process safety and environmental issues, the EPA starting from pollution prevention and control and OSHA from work place safety [1].

    Waste water, emissions, contamination of soil and ground water, waste disposals system employee health and safety are the potential concerns. The disposal and management of toxic substances like process related wastes and residues from waste plant treatments receive cynosure due to strict regulations and commerce. The waste management and control are more systematic and integrated due to the environmental effects which are more complex. Effective waste minimization and pollution control measures are employed at each and every stage of product life which is recognized throughout the world, and the main criteria of any company is to manufacture products while generating least amount of wastes [2].


    Commit to process safety -this is the key point of process safety excellence. The organization that fully supports safety as a core value and also convinces the workforce in the organization tend to do right things at the right times, even when no one else is looking.

    Understand hazards and risks -this is the foundation of risks-based approach. An organization can use this information to allocate limited resources in the most effective manner. As a result the limited resources can also ensure that they are used efficiently.

    Manage risk-The ongoing exclusions of RBPS tasks -Organization must Operate and maintain the processes that pose the risk, Carry on necessary changes to those processes within risk tolerances, and Prepare for, respond to, and manage incidents that can harm the environment. Companies that understand its risks and follows safety measures, subsequently, sustain long term, accident -free and profitable operations.

    Learn from experience-experiences are the opportunities for improvement. Metrics provide direct feedback on the working of RBPS systems, and leading indicators provide early warning signals of ineffective process safety results. When an element's performance is unacceptable, organizations must use their mistakes and also those of others as motivation for action and improvement [3].

    As a result, since many of these operations are performed manually human presence should be eliminated as much as possible by incorporating advance technologies. And also the flammables like toxic materials should be released into environment in a scientific manner. To ensure that all these takes place safely certain agencies and firms are established.

    The environment agency's main concern to ensure the safe management of hazardous materials. The agencies do not expect to see mixing of hazardous waste with non- hazardous waste to dilute or obscure the hazardous waste. Mixing of hazardous with non hazardous wastes may damage the environment or human health. The purpose of render hazardous to non hazardous is to minimize or reduce the risks when disposed of in a suitable landfill. We can find sometimes, unsuited reaction occurs at end of the process, because of no proper knowledge plant operator on treatment of hazardous materials. To convert hazardous waste to non-hazardous, the physical processes are not often adequate .so chemical processes are also required in some cases. Environmental agency position expect treatment plant operator to be aware of inputs to their processes, to ensure that the appropriate control over the output such that hazardous and non hazardous wastes are properly disposed of. Landfill operators also should understand the process of treatment. The managers and producers of hazardous wastes that suspect others inaccurately classifying or managing hazardous waste should inform environment agency. The environment agency looks ahead to the treatment industry and land filling sector to ensure the effective chemicals for safe management of hazardous waste [4].

    References for 3):-

    [1] Sam Mannan (2009); Frank P. Lees (2009). "Lee's Loss Prevention in the process industries: Hazard", volume 1, page 3/3.

    [2] Patrick Eyraud (1992); Daniel j.watts (1992). "EPA Environmental research brief: waste reduction activities and options for a manufacturer of fine chemicals using batch processes.

    [3] Guidelines for Risk Based Process Safety, 2007. [Online]. Last accessed on 12 November 2009 at:

    [4]Laura Sam brook. Treatment and land filling of hazardous waste. 2007. [Online]. Last accessed on 12 November 2009 at:

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