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Solvent Safety

Published: 29th May 2014 in OSA Magazine

When it comes to dealing with chemicals safety is not an option - it is an absolute necessity. As outlined in his article, Venkatesh Ganapathy knows that being fully protected against chemical hazards is imperative.

Chemical protective clothing helps safeguard men and women from chemical hazards that can and can’t be seen, such as dangerous vapours, liquids and particles. These hazards occur in industries that make chemicals, perfumes, solvents, chemical reagents and other inflammable liquids. Even in the oil industry, where chemicals are used as a raw material, workers will still need chemical protection.

One of the raw materials used in the lube oil industry is a polymer that acts as a viscosity index improver. This polymer, which is akin to a huge translucent piece of rubber, helps engine oil to remain fluid at all temperatures. These engine oils are called multi grade engine oils.

Case studies

During the early 1990s I was working at a lube oil manufacturing plant in Mumbai, which had not yet seen the introduction of plant automation. I was astounded to see workers sitting on the shop floor cutting polymer pieces - as if they were cutting carrots. They wore no chemical protection and days later they had blisters on their hands.

Large organisations pay great attention to increasing productivity in manufacturing plants, but very often it comes at the cost of diluted safety standards. Failure to wear chemical protective clothing and equipment can stem from many areas. In some instances workers are not aware that chemical protection is required, or if required that it is in fact available. On other occasions, factory management does not do enough to motivate workers to use the chemical protection. These instances occur despite India’s 1948 Factories Act, which stresses the need for safe working practises.

On another occasion, I had the misfortune of watching a few workers in our plant blending bitumen in a blending vessel with little protection - no nose masks, no eye protection, no gloves. Granted they were wearing safety shoes, but what is the use of incomplete protection? Bitumen is a chemical that on heating can emit hazardous vapours.

Protective clothing

Prior to selecting the protective clothing it is important to conduct a risk assessment. Chemical protective clothing is not a substitute for other safety measures; it is only a complementary aid. It is the last line of defence for protecting the skin and so care must be taken to ensure that it provides the protection expected. The purpose of chemical protective clothing and equipment is to shield or isolate individuals from the chemical, physical and biological hazards that may be encountered during hazardous material operations.

Overcoming disasters

During chemical operations, it is not always apparent that exposure has occurred. Many chemicals pose invisible hazards and offer no warning properties. In a factory manufacturing hydrocarbons, for example, if the temperature control fails or if there is an unexpected reaction between two chemicals in the process this can spell disaster. You need only to recall the infamous Bhopal gas tragedy or the explosion in BP’s Texas factory to know the consequences of such an event.

All chemicals have certain physicochemical characteristics including different colours, boiling and melting points and specific gravity. Even if you have the best process and operating procedure in the world, things could still go wrong if workers are not sufficiently trained or processes are not correctly followed.

When BP’s Texas refinery accident occurred it brought shame to the company, as prior to this its safety policy had boasted claims of no accidents, no harm to people and no damage to the environment. After several months of investigation, BP introduced something known as the integrity management standard, as investigations revealed that while BP had good product safety, there were improvements to be made in process safety.

We also need to remember that in most cases, incomplete research efforts add to the complexity. As an example, let’s say I have a process to make product C, by using raw materials A and B. What would happen if an important step in the process was not followed religiously, or if B were substituted with D, a similar but different raw material, due to cost or availability issues? Under intense pressure from manufacturers, the research and development and quality control departments could be forced to approve the new material, potentially without sufficient prior investigation.

Protective gloves

It is a common misconception that all gloves are resistant to chemicals. No glove can remain impervious to a substance forever, especially to a chemical. The quality of the gloves and the nature of the chemicals both play an important role in protection. Generally, the information provided on the Material Safety Data Sheet (MSDS) needs to be followed, as will be detailed more fully later.

When selecting gloves, we need to understand what is meant by permeation rate, breakthrough time and degradation. Permeation rate is the speed at which the chemical will move through the material. The higher the permeation rate, the faster the chemical will move through the material.

Breakthrough time is the time it takes a chemical to permeate completely through the material. To measure this, a chemical is applied on the exterior of the glove and then the time taken to detect the chemical on the inside surface is recorded. The breakthrough time gives some idea of how long a glove can safely be used before the chemical permeates through the material.

Degradation is the measurement of the material’s physical deterioration due to contact with a chemical. In the worst cases, the material may dissolve in the chemical.

When working with chemicals with high acute toxicity, working with corrosives in high concentrations, handling chemicals for extended periods of time, or immersing all or part of the hand into a chemical, the appropriate glove material should be selected based on chemical compatibility.

Material Safety Data Sheet

As touched upon briefly earlier in this article, the MSDS is a document that contains details about the physicochemical properties of a chemical, as well as the precautions to be taken while handling it. The MSDS also contains the corrective actions to be taken in case of chemical spills, or if there is an accident involving the chemical.

In many countries the MSDS is a legal requirement. No research and development or manufacturing plant can aspire to get a quality certification if they do not have the MSDS outlining the chemicals used. Companies who are certified for ISO 14000 insist that suppliers of chemicals must provide the MSDS along with every consignment of chemicals. When chemicals are transported in bulk, it is mandatory by law that the transporter must carry sufficient copies of the MSDS. 

Unfortunately, there is a problem here. Many organisations use the MSDS for supporting their quality systems, but seldom do firms conduct training programmes to do the same. When there is an accident, it is common to see people scrambling to find out information.

Selecting protection

Steps in deciding the chemical protective clothing:
• Have a clear cut description of the task to be performed
• Identify all hazards that may require hand protection
• Identify other hazards that require protection
• Understand hazards that can occur despite wearing chemical protection
• Consider the duration that the worker could be in contact with the chemical, and the type of chemicals, as this may influence the selection of the type of protective clothing
• Consider the immediate irritation or corrosion that would be caused by to the skin’s potential chemical exposure, as well as deleterious health effects to other parts of the body
• Train workers and management to identify the hazards present and to know the type of chemical protective clothing needed
• Formulate a contingency plan in case the clothing fails to deliver

When there is a possibility of chemical contamination, protective clothing that resists physical and chemical hazards should be worn over street clothes. Lab coats are good for minor chemical splashes. Plastic or rubber aprons are best for protection from corrosiveor irritating liquids. In some cases, cleaning and decontamination of reusable clothing can not only be cumbersome, but also an expensive affair. In such cases, disposable outer garments may be useful.

Chemical raw materials

I recall the time when I visited the office of International Flavors and Fragrances in Powai, Mumbai, where the office and lab are adjacent to one another. Despite the fact that I did not even enter the lab, the odour of fragrances was so strong that I immediately developed an allergy.

Perfumes and deodorants are fine when you spray them on your body because they are in diluted forms, but if you go to a lab or a factory where perfumes are manufactured, the odour of the chemical raw materials, or hydrocarbons, is so strong that if you are not wearing a face mask you will quickly develop an allergy.

In some labs, particularly those using large quantities of solvents, chemical resistant shoes or boots are a must. Leather shoes can be contaminated or sometimes permanently damaged when they come into contact with a chemical.

Dimethyl sulfoxide (DMSO) and nitrobenzene are examples of chemicals that can be readily absorbed through the skin into the bloodstream. There is an apocryphal story that emphasises the importance of wearing protective eyewear, in which a lab chemist once opened a reagent bottle containing ammonia and was blinded. The story shows that protection must be all encompassing. A person opening the bottle of reagent may wear protective clothing, gloves and footwear and consider themselves safe, yet forgetting to wear eye protection could cost them dearly.

Even with protective eyewear donned, however, accidents can still occur. Before commencing work in a plant that uses chemicals, it is important to store to your memory the location of the emergency showers and eye bath facilities.

Combining protection

No single combination of protective equipment and clothing is capable of protecting you against all hazards, so protective clothing should be used in conjunction with other protective methods. The use of protective clothing can itself create significant wearer hazards, such as heat stress, physical and psychological stress, in addition to impaired vision, mobility and communication. The greater the level of chemical protective clothing, the greater the associated risk. Chemical protection is required in applications such as chemical manufacturing, process industries, hazardous waste site clean up and disposal, and in the application of agricultural pesticides.

Reliance on one particular type of clothing or equipment item may severely limit a facility’s ability to handle a broad range of chemical exposures. In the procurement of protective equipment and clothing, the safety department or other responsible authority should attempt to provide a high degree of flexibility when choosing protective clothing and equipment. This should help to ensure that it is easily integrated and provides protection against every conceivable hazard.

Standard operating procedures

One fundamental principle for ensuring greater compliance with chemical protection is to have standard operating procedures (SOPs). SOPs are procedures that are clearly written down and documented. They also include a list of dos and don’ts; for example, a SOP on handling a particular chemical will include step by step details of the procedure.

A quality system mandates that SOPs are used for research, manufacturing and quality testing. It is a good practise to have SOPs for workers handling all chemicals, more so if it is a hazardous chemical. For Single Point Accountability (SPA) it makes sense to delegate responsibility to a single point of contact. This person must be trained in handling hazardous chemicals, as well as in how to select the correct protection. In cases where the chemical hazards are known in advance or encountered routinely, clothing selection should be predetermined.

The following points outline some of the important precautions that need to be internalised:
• Work practises that minimise contact with hazardous substances should be stressed; for example, do not walk through areas of obvious contamination nor directly touch potentially hazardous substances
• Wear disposable outer garments and use disposable equipment where appropriate
• Cover equipment and tools with a strippable coating that can be removed during decontamination
• Encase the source of contaminants, e.g. with plastic sheeting or overpacks
• Ensure all closures and ensemble component interfaces are completely secured and that no open pockets are present, as these could serve to collect contaminants

Failure to internalise these precautions brings me to recall an accident that took place in a chemical lab in my institution in 1991, in which a doctoral research scholar was doing research that involved monitoring a chemical reaction in an autoclave. He was also using an oxygen cylinder, which suddenly burst, severely injuring the student and a lab assistant. Both were admitted to a nearby hospital. Neither was wearing any form of protection, because they never imagined that such an accident would occur. The lab assistant suffered visual impairment, while the student had to undergo plastic surgery.

Inspection

Inspection plays an important role in ensuring chemical protection is effective. There are five different kinds of inspections:
• Inspection and operational testing of equipment received, as new, from the factory or distributor
• Inspection of equipment as it is selected for a particular chemical operation
• Inspection of equipment after use or training and prior to maintenance
• Periodic inspection of stored equipment
• Periodic inspection when a question arises concerning the appropriateness of selected equipment, or when problems with similar equipment are discovered

Each inspection will cover different areas with varying degrees of depth. Those personnel responsible for clothing inspection should follow manufacturer directions, as many vendors provide detailed inspection procedures.

Records must be kept of all inspection procedures. If not already allocated by serial number, individual identification numbers should be assigned to all reusable pieces of equipment, and records should be maintained by that number. Periodic review of these records can provide an indication of the protective clothing that requires excessive maintenance and can also serve to identify clothing that is susceptible to failure.

The discomfort and inconvenience of wearing chemical protective clothing and equipment can create a resistance to its use. For some individuals, especially those working in labs, for example, wearing gloves makes it difficult to handle reagent bottles. Others prefer not to use safety goggles as they can cause discomfort. This is the reason that the selection of protective equipment should bring user comfort into consideration. Training is essential, not only to make the user aware of the need for protective clothing, but also to instil motivation for its proper use and maintenance.

Heat stress

Wearing full body chemical protective clothing puts the wearer at considerable risk of developing heat stress. This can result in health effects ranging from transient heat fatigue to serious illness or death.

Heat stress is caused by a number of interacting factors:
• Environmental conditions
• Type of protective ensemble worn
• Work activity required
• Individual characteristics of the responder

When selecting chemical protective clothing and equipment, each item’s benefit should be carefully evaluated against its potential to increase the risk of heat stress. If a lighter, less insulating suit can be worn without sacrificing protection, then it should be selected. Reflective clothing is another option to keep workers cool. As the incidence of heat stress depends on a variety of factors, all workers wearing full body chemical protective ensembles should be monitored.

Selectively permeable membranes have been introduced to improve protection, but how effective they are against heat strain is not known. The use of permeable membranes with low vapour resistance has been explored. In addition, air permeability increases can reduce heat strain levels, allowing optimisation of chemical protective clothing. The use of such membranes may optimise protection, but one needs to consider in depth the wearer’s heat strain before making any decisions or purchases.

Employees need to be trained on how to deal with heat stress, starting with recognising its signs. Supervisors should schedule physically demanding tasks during cooler parts of the day and provide alternate tasks when possible. Importantly, workers need to keep themselves hydrated, be physically fit, take regular breaks and should never work alone in hot areas.

Conclusion

Human life is precious and one cannot be reckless in dealing with chemicals. Chemical protective clothing can effectively safeguard men and women from hazards while dealing with chemicals. Users should ensure they wear the right protective clothing of a good standard.

If something is not comfortable, rather than eschewing wearing the clothing, workers should bring this to the attention of their supervisors. Organisations should make training part of the firm’s ecosystem, so that workers dealing with hazardous chemicals are aware of the risks. Risks are dynamic and so it is important that vigilance replaces complacence.

Non compliance in following instructions to wear protective clothing can lead to injury, loss of life and potential loss of employment – none of which are acceptable situations for any individual. Monitor the risks on an ongoing basis and never take anything for granted. As always, it is better to be safe than sorry.

Published: 29th May 2014 in OSA Magazine

Author


Venkatesh Ganapathy


Venkatesh Ganapathy graduated in oil technology from UDCT, Mumbai, in 1992. He worked in Castrol India Limited and Panasonic Firepro Systems Pvt Ltd before moving into academia full time. He has completed his postgraduate management degree from Southern New Hampshire University. Additionally, he is a fellow of the Insurance Institute of India, Mumbai, and has a diploma in supply chain management from APICS. Teaching and writing are his twin passions. 

Presently, Venkatesh works as an Associate Professor in the Presidency School of Business, Bangalore, teaching the following subjects: Marketing, Production Operations Management and General Management. He is also pursuing his doctoral degree from Alliance University, Bangalore. He has written several technical and non-technical articles on diverse topics, and also a few research papers.


Venkatesh Ganapathy

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