Reducing the risk of accidents with wireless communications

Paul Boughton

Patric Hogstrom looks at how on-site wireless communications helps you comply with regulations for security, worker-safety and environmental protection.

The manufacture and processing of chemicals is a highly capital- and resource-intensive, and potentially dangerous, business. There is hardly any room for product differentiation or innovation: production methods are well-established and widely known. The only way to make a profit is to maximise efficiency and continuity, while paying close attention to safety. Wireless communications can make a valuable contribution in all these areas.


The chemical industry is a classic commodity business -- particularly at the aheavier' end of the scale, in areas like basic organic and inorganic compounds, fertilisers, gasoline and plastics. The supply chain is typically rather long and complex, and involves many transactions, with extremely tight margins. This is true whether it is a cracker plant producing several different chemical products, each with a small group of customers, or a refinery making products for an enormous range of customers.


The chemical industry is also very transparent. Most of the technology and processes have been known about for 50 years or more, and there are virtually no commercial asecrets' and very few patents. Feedstock prices are out of the control of the producer, as are prices for the end-product, which vary widely according to global demand for the end-product -- meaning margins also vary significantly. Profitability is therefore all about making products faster and cheaper on a scale that can smooth out the effects of global price fluctuations.


Another key attribute of the chemical industry is its absolute focus on safety. This is not just a question of being a good employer that meets regulations; it is also a matter of business rationale: unsafe plants that are prone to accidents are unlikely to be profitable.

Safety first

While chemical manufacturing has one of the best safety records of any industry in terms of accidents per man-hour, the dangers of leakage, fire and explosions are ever-present. Identifying and acting on problems early on is key to preventing small faults snow-balling into major incidents.


Wireless communications supports the fast, accurate execution of routines for dealing with faults and emergency situations -- whether in the first, second or third alines of defence'. The communications solution can be integrated with plant monitoring and alarm systems so that critical alarms immediately trigger an alert to the most appropriate person. The reason for an alarm is always clear and precise.


Group calling functions enable emergency response teams to open a communications channel and talk to each other at the touch of a button, if the problem needs wider attention. Wide-area mobile communications can also be integrated so that a specialist can be contacted if necessary on a mobile phone, even when off site.


With features like 'man down' and positioning, wireless communications systems could be a real life-saver for people who are often working alone or out of sight in a large chemical plant.

A risk-analysis model

An important task of any risk analysis is to identify the error sources and to attempt to predict how an error propagates and causes an accident. For instance according to this model:


1. Deviation: A deviation occurs (drifting process parameters, leakage of toxic or explosive substances). The deviation goes unnoticed (broken sensor). The deviation grows (alarm fails to reach right person quickly enough).
2. Hazardous event: The deviation grows into a hazardous event (pressure in a tank reaches a critical level, explosive substance reaches a dangerous concentration). The hazardous event goes unnoticed (broken sensor). The hazardous event grows (alarm fails to reach right person quickly enough).
3. Accident: The hazardous event escalates (someone begins welding a ignites leaking gas). Hazardous event grows into an accident.


A good risk analysis clarifies how to prevent the consequences of unintentional disturbances (human error, technical failure), and intentional disturbances (theft, sabotage). One challenge is that risk analyses are seldom comprehensive. It is difficult to correctly identify all the errors capable of causing serious accidents. It is even more difficult to accurately predict all the possible patterns of error propagation. It is therefore crucial that the organisation can take action quickly in response to problems. Also, the organisation must have the capability to react to unforeseen error propagation. In addition, all alarms should be logged. This increases the chances that the organisation quickly finds the primary error when many alarms come almost simultaneously. Logging makes it simpler to eliminate systematic errors and minimise risk levels long term.

Quicker response reduces risk

On-site wireless communications enable quicker response to disturbances that can harm people, property and the environment. Key staff in safety, production and management gets alarms right into the pocket. Wherever they are, designated personnel get clear, unambiguous information on what has happened and where. Staff can communicate with safety systems and processes. They can talk one on one or in conference calls -- throughout the plant, through concrete walls and in noisy environments. They can nip many problems in the bud, and reduce the risk of accidents.

More effective damage control

Even when an accident has occurred, quicker response helps minimise the consequences. For example, in the event of an accidental discharge of cleaning agent, the company can alert the sewage treatment plant, so they can take action and minimise the damage. In the event of a serious accident, safety personnel can get information about the number and location of people in the risk zone. They can quickly set up conference calls with management, outside specialists and emergency services. Wireless communications speeds up the dissemination of information to the press and public. Company spokesmen can sooner replace We still don't have any information" with: "At 8.16 am a small amount of ethylene oxide leaked from tank 12. The situation is now under control. No injuries have been reported."


On-site wireless communications helps you comply with regulations for securityworker-safety and environmental protection. And this adds up to higher profitability.

Enter 33 or at www.engineerlive.com/ece

Patric Hogstrom is Business Unit Manager for IndustryAscom Wireless SolutionsGothenburgSweden. www.ascom.com/ws

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