The Importance of Gas Detection in the Power Industry

The energy industry is the very backbone of our industrial and domestic worlds, supplying essential energy to industrial, manufacturing, commercial and residential customers around the globe. With the inclusion of fossil fuel industries (petroleum, coal, LNG); electricity generation, distribution and sales; nuclear energy and renewable energy, the power generation sector is essential in supporting the increasing demand for power from emerging countries and an increasing world population.

Gas Hazards in Power Sector

Gas detection systems have been installed extensively in the power industry to minimise potential consequence through the detection of gas exposure with those working within this industry are exposed to a variation of power plant gas hazards.

Carbon monoxide

The transport and pulverisation of coal poses a high risk of combustion. Fine coal dust becomes suspended in air and highly explosive. The smallest spark, for example from plant equipment, can ignite the dust cloud and cause an explosion that sweeps up more dust, which explodes in turn, and so on in a chain reaction. Coal power plants now require combustible dust certification, in addition to hazardous gas certification.

Coal power plants generate large volumes of carbon monoxide (CO) which is both highly toxic and flammable and must be accurately monitored. A toxic component of incomplete combustion, CO comes from boiler casing leaks and smouldering coal. It is vital to monitor CO in coal tunnels, bunkers, hoppers and tipper rooms, along with infrared-type flammable gas detection to detect pre-fire conditions.

Hydrogen

With hydrogen fuel cells gaining popularity as alternatives to fossil fuel, it is important to be aware of the dangers of hydrogen. Like all fuels, hydrogen is highly flammable and if it leaks there is real risk of fire. Hydrogen burns with a pale blue, almost invisible, flame that can cause serious injuries and severe equipment damage. Therefore, hydrogen must be monitored, to prevent seal-oil system fires, unscheduled shutdowns and to protect personnel from fire.

In addition, power plants must have back-up batteries, to ensure the continued functioning of critical control systems in cases of power outage. Battery rooms generate considerable hydrogen, and monitoring is often carried out in conjunction with ventilation. Traditional lead acid batteries produce hydrogen when they are being charged. These batteries are normally charged together, sometimes in the same room or area, which can generate an explosion risk, especially if the room is not properly ventilated.

Confined Space Entry

Confined space entry (CSE) is often considered to be a dangerous type of work performed in power generation. It is therefore important that the entry is strictly controlled and detailed precautions are taken. Lack of oxygen, toxic and flammable gases are risks that can occur during work in confined spaces, which should never be considered as simple or routine. However, the hazards of working in confined spaces can be predicted, monitored, and mitigated through the use of portable gas detection devices. Confined Spaces Regulations 1997. Approved Code of Practice, Regulations and guidance is for employees that work in Confined Spaces, those who employ or train such people and those who represent them.

Our Solutions

Elimination of these gas hazards is virtually impossible, so permanent workers and contractors must depend on reliable gas detection equipment to protect them. Gas detection can be provided in both fixed and portable forms. Our portable gas detectors protect against a wide range of gas hazards, these include T4x, Gasman, Tetra 3,Gas-Pro, T4, and Detective+. Our fixed gas detectors are used in many applications where reliability, dependability and lack of false alarms are instrumental to efficient and effective gas detection, these include Xgard, Xgard BrightXgardIQ and IRmax. Combined with a variety of our fixed detectors, our gas detection control panels offer a flexible range of solutions that measure flammable, toxic and oxygen gases, report their presence and activate alarms or associated equipment, for the power industry our panels include Vortex and Gasmonitor.

To find out more on the gas hazards in the power industry visit our industry page for more information.

Industry Overview: Waste to Energy

The waste to energy industry utilises several waste treatment methods. Municipal and industrial solid waste is converted into electricity, and sometimes into heat for industrial processing and district heating systems. The main process is of course incineration, but intermediate steps of pyrolysis, gasification, and anaerobic digestion are sometimes used to convert the waste into useful by-products that are then used to generate power through turbines or other equipment. This technology is gaining wide recognition globally as a greener and cleaner form of energy than traditional burning of fossil fuels, and as a means of reducing waste production.

Types of waste to energy

Incineration

Incineration is a waste treatment process that involves the combustion of energy rich substances contained within waste materials, typically at high temperatures around 1000 degrees C. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities and are often sizeable power stations in their own right. Incineration and other high-temperature waste treatment systems are often described as “thermal treatment”. During the process waste is converted into heat and steam that can be used to drive a turbine in order to generate electricity. This method currently has an efficiency of around 15-29%, although it does have potential for improvements.

Pyrolysis

Pyrolysis is a different waste treatment process where decomposition of solid hydrocarbon wastes, typically plastics, takes place at high temperatures without oxygen present, in an atmosphere of inert gases. This treatment is usually conducted at or above 500 °C, providing enough heat to deconstruct the long chain molecules including bio-polymers into simpler lower mass hydrocarbons.

Gasification

This process is used to make gaseous fuels from heavier fuels and from waste containing combustible material. In this process, carbonaceous substances are converted into carbon dioxide (CO2), carbon monoxide (CO) and a small amount of hydrogen at high temperature. In this process, gas is generated which is a good source of usable energy. This gas can then be used to produce electricity and heat.

Plasma Arc Gasification

In this process, a plasma torch is used to ionise energy rich material. Syngas is produced which may then be used to make fertiliser or generate electricity. This method is more of a waste disposal technique than a serious means of generating gas, often consuming as much energy as the gas it produces can provide.

Reasons for Waste to Energy

As this technology is gaining wide recognition globally in regards to waste production and the demand for clean energy.

  • Avoids methane emissions from landfills
  • Offsets greenhouse gas (GHG) emissions from fossil fuel electrical production
  • Recovers and recycles valuable resources, such as metals
  • Produces clean, reliable base-loaded energy and steam
  • Uses less land per megawatt than other renewable energy sources
  • Sustainable and steady renewable fuel source (compared to wind and solar)
  • Destroys chemical waste
  • Results in low emission levels, typically well below permitted levels
  • Catalytically destroys nitrogen oxides (NOx), dioxins and furans using an selective catalytic reduction (SCR)

What are the Gas Hazards?

There are many processes to turn waste into energy, these include, biogas plants, refuse use, leachate pool, combustion and heat recovery. All these processes pose gas hazards to those working in these environments.

Within a Biogas Plant, biogas is produced. This is formed when organic materials such as agricultural and food waste are broken down by bacteria in an oxygen-deficient environment. This is a process called anaerobic digestion. When the biogas has been captured, it can be used to produce heat and electricity for engines, microturbines and fuel cells. Clearly, biogas has high methane content as well as substantial hydrogen sulphide (H2S), and this generates multiple serious gas hazards. (Read our blog for more information on biogas). However, there is an elevated risk of, fire and explosion, confined space hazards, asphyxiation, oxygen depletion and gas poisoning, usually from H2S or ammonia (NH3). Workers in a biogas plant must have personal gas detectors that detect and monitor flammable gas, oxygen and toxic gases like H2S and CO.

Within a refuse collection it is common to find flammable gas methane (CH4) and toxic gases H2S, CO and NH3. This is because refuse bunkers are built several metres underground and gas detectors are usually mounted high up in areas making those detectors hard to service and calibrate. In many cases, a sampling system is a practical solution as air samples can be brought to a convenient location and measured.

Leachate is a liquid that drains (leaches) from an area in which waste is collected, with leachate pools presenting a range of gas hazards. These include the risk of flammable gas (explosion risk), H2S (poison, corrosion), ammonia (poison, corrosion), CO (poison) and adverse oxygen levels (suffocation). Leachate pool and passageways leading to the leachate pool requiring monitoring of CH4, H2S, CO, NH3, oxygen (O2) and CO2. Various gas detectors should be placed along routes to the leachate pool, with output connected to external control panels.

Combustion and heat recovery requires the detection of O2 and toxic gases sulphur dioxide (SO2) and CO. These gases all pose a threat to those who work in boiler house areas.

Another process that is classed as a gas hazard is an exhaust air scrubber. The process is hazardous as the flue gas from incineration is highly toxic. This is because it contains pollutants such as nitrogen dioxide (NO2), SO2, hydrogen chloride (HCL) and dioxin. NO2 and SO2 are major greenhouse gases, while HCL all of these gas types mentioned here are harmful to human health.

To read more on the waste to energy industry, visit our industry page.

An Introduction to the Oil and Gas Industry 

The oil and gas industry is one of the biggest industries in the world, making a significant contribution to the global economy. This vast sector is often separated into three main sectors: upstream, midstream and downstream. Each sector comes with their own unique gas hazards. 

Upstream

The upstream sector of the oil and gas industry, sometimes referred to as exploration and production (or E&P), is concerned with locating sites for oil and gas extraction the subsequent drilling, recovery and production of crude oil and natural gas. Oil and gas production is an incredibly capital-intensive industry, requiring the use of expensive machinery equipment as well as highly skilled workers. The upstream sector is wide-ranging, encompassing both onshore and offshore drilling operations. 

The major gas hazard encountered in upstream oil and gas is hydrogen sulphide (H2S), a colourless gas known by its distinct rotten egg like smell. H2S is a highly toxic, flammable gas which can have harmful effects on our health, leading to loss of consciousness and even death at high levels. 

Crowcon’s solution for hydrogen sulphide detection comes in the form of the XgardIQ, an intelligent gas detector which increases safety by minimising the time operators must spend in hazardous areas. XgardIQ is available with high-temperature H2S sensor, specifically designed for the harsh environments of the Middle East. 

Midstream

The midstream sector of the oil and gas industry encompasses the storage, transportation and processing of crude oil and natural gas. The transportation of crude oil and natural gas is done by both land and sea with large volumes transported in tankers and marine vessels. On land, transportation methods used are tankers and pipelines. Challenges within the midstream sector include but are not limited to maintaining the integrity of storage and transportation vessels and protecting workers involved in cleaning, purging and filling activities. 

Monitoring of storage tanks is essential to ensure the safety of workers and machinery. 

Downstream

The downstream sector refers to the refining and processing of natural gas and crude oil and the distribution of finished products. This is the stage of the process where these raw materials are transformed into products which are used for a variety of purposes such as fuelling vehicles and heating homes.  

The refining process for crude oil is generally split into three basic steps: separation, conversion and treatment. Natural gas processing involves separating the various hydrocarbons and fluids to produce ‘pipeline quality’ gas. 

The gas hazards which are typical within the downstream sector are hydrogen sulphide, sulphur dioxide, hydrogen and a wide range of toxic gases. Crowcon’s Xgard and Xgard Bright fixed detectors both offer a wide range of sensor options to cover all the gas hazards present in this industry. Xgard Bright is also available with the next generation MPS™ sensor, for the detection of over 15 flammable gases in one detector. Also available are both single and multi-gas personal monitors to ensure workers safety in these potentially hazardous environments. These include the Gas-Pro and T4x, with Gas-Pro providing 5 gas support in a compact and rugged solution.

The importance of gas detection in the Petrochemical Industry

Closely linked to oil and gas, the petrochemicals industry takes raw materials from refining and gas processing and, through chemical process technologies, converts them into valuable products. In this sector, the organic chemicals produced in the largest volumes are methanol, ethylene, propylene, butadiene, benzene, toluene and xylenes (BTX). These chemicals are the building blocks of many consumer goods including plastics, clothing fabric, construction materials, synthetic detergents and agrichemical products.

Potential Hazards

Exposure to potential hazardous substances is more likely to occur during shutdown or maintenance work as these are a deviation from the refinery’s routine operations. As these deviations are out of normal routine, care should be exercised at all times to avoid the inhalation of solvent vapours, toxic gases, and other respiratory contaminants. The assistance of constant automated monitoring is helpful in determining the presence of solvents or gases, allowing their associated risks to be mitigated. This includes warning systems such as gas and flame detectors, supported by emergency procedures, and permit systems for any kind of potentially dangerous work.

The petroleum industry is split into upstream, midstream and downstream and these are defined by the nature of the work that takes place in each area. Upstream work is typically known as the exploration and production (E&P) sector. Midstream refers to the transportation of products through pipelines, transit and oil tankers as well as the wholesale marketing of petroleum-based products. The downstream sector refers to the refining of petroleum crude oil, the processing of raw natural gas and the marketing and distribution of finished products.

Upstream

Fixed and portable gas detectors are needed to protect plant and personnel from the risks of flammable gas releases (commonly methane) as well as from high levels of H2S, particularly from sour wells. Gas detectors for O2 depletion, SO2 and volatile organic compounds (VOCs) are required items of personal protection equipment (PPE), which is usually highly visible colour and worn near breathing space. Sometimes HF solution is used as a scouring agent. Key requirements for gas detectors are rugged and reliable design and long battery life. Models with design elements that support easy fleet management and compliance obviously have an advantage. You can read about VOC risk and Crowcon’s solution in our case study.

Midstream

Fixed monitoring of flammable gases situated close to pressure relief devices, filling and emptying areas is necessary to deliver early warning of localised leaks. Multi-gas portable monitors must be used to maintain personal safety, especially during work in confined spaces and supporting hot work permit area testing. Infrared technology in flammable gas detection supports purging with the ability to operate in inert atmospheres and delivers reliable detection in areas where pellistor type detectors would fail, due to poisoning or volume level exposure. You can read more on how infrared detection works in our blog and read our case study of infrared monitoring in refinery settings in Southeast Asia.

Portable laser methane detection (LMm) allows users to pin-point leaks at distance and in hard-to-reach areas, reducing the need for personnel to enter potentially dangerous environments or situations while performing routine or investigative leak monitoring. Using LMm is a quick and effective way to check areas for methane with a reflector, from up to 100m away. These areas include closed buildings, confined spaces and other difficult-to-reach areas such as above-ground pipelines that are near water or behind fences.

Downstream

In downstream refining, the gas risks may be almost any hydrocarbon, and may also include hydrogen sulphide, sulphur dioxide and other by-products. Catalytic flammable gas detectors are one of the oldest flammable gas detector types. They work well, but must have a bump testing station, to ensure each detector responds to the target gas and is still functional. The ongoing demand to reduce facility down-time whilst ensuring safety, especially during shutdown and turnaround operations, means that gas detection manufacturers must deliver solutions offering ease of use, straightforward training and reduced maintenance times, along with local service and support.

During plant shutdowns, processes are stopped, items of equipment are opened and checked and the number of people and moving vehicles at the site is many times higher than normal. Many of the processes undertaken will be hazardous and require specific gas monitoring. For example, welding and tank cleaning activities require area monitors as well as personal monitors to protect those on site.

Confined space

Hydrogen sulphide (H2S) is a potential problem in the transport and storage of crude oil. The cleaning of storage tanks presents a high hazard potential. Many confined-space entry problems can occur here, including oxygen deficiency resulting from previous inerting procedures, rusting, and oxidation of organic coatings. Inerting is the process of reducing the oxygen levels in a cargo tank to remove the oxygen element required for ignition. Carbon monoxide can be present in the inerting gas. In addition to H2S, depending on the characteristics of the product previously stored in the tanks, other chemicals that may be encountered include metal carbonyls, arsenic, and tetraethyl lead.

Our Solutions

Elimination of these gas hazards is virtually impossible, so permanent workers and contractors must depend on reliable gas detection equipment to protect them. Gas detection can be provided in both fixed and portable forms. Our portable gas detectors protect against a wide range of gas hazards, these include Clip SGD, Gasman, Tetra 3,Gas-Pro, T4, Gas-Pro TK and Detective+. Our fixed gas detectors are used in many applications where reliability, dependability and lack of false alarms are instrumental to efficient and effective gas detection, these include Xgard, Xgard Bright, Fgard IR3 Flame Detector and IRmax. Combined with a variety of our fixed detectors, our gas detection control panels offer a flexible range of solutions that measure flammable, toxic and oxygen gases, report their presence and activate alarms or associated equipment, for the petrochemical industry our panels include Addressable Controllers, Vortex and Gasmonitor.

To find out more on the gas hazards in the petrochemical industry visit our industry page for more information.

The importance of Gas Detection in the Water and Wastewater Industry 

Water is vital to our daily lives, both for personal and domestic use and industrial/commercial applications. Whether a facility focuses on the production of clean, potable water or treating effluent, Crowcon is proud to serve a wide variety of water industry clients, providing gas detection equipment that keeps workers safe around the world. 

Gas Hazards 

Apart from common gas hazards known in the industry; methane, hydrogen sulphide, and oxygen, there are bi-product gas hazards and cleaning material gas hazards that occur from purifying chemicals such as ammonia, chlorine, chlorine dioxide or ozone that are used in the decontamination of the waste and effluent water, or to remove microbes from clean water. There is great potential for many toxic or explosive gases to exist as a result of the chemicals used in the water industry. And added to these are chemicals that may be spilled or dumped into the waste system from industry, farming or building work. 

Safety Considerations  

Confined Space Entry 

The pipelines used to transport water require regular cleaning and safety checks; during these operations, portable multi-gas monitors are used to protect the workforce. Pre-entry checks must be completed prior to entering any confined space and commonly O2, CO, H2S and CH4 are monitored. Confined spaces are small, so portable monitors must be compact and unobtrusive for the user, yet able to withstand the wet and dirty environments in which they must perform. Clear and prompt indication of any increase in gas monitored (or any decrease for oxygen) is of paramount importance – loud and bright alarms are effective in raising the alarm to the user. 

Risk assessment 

Risk assessment is critical, as you need to be aware of the environment that you are entering and thus working in. Therefore, understanding the applications and identifying the risks regarding all safety aspects. Focusing on gas monitoring, as part of the risk assessment, you need to be clear on what gases may be present.  

Fit for purpose 

There is a variety of applications within the water treatment process, giving the need to monitor multiple gases, including carbon dioxide, hydrogen sulphide, chlorine, methane, oxygen, ozone and chlorine dioxide. Gas detectors are available for single or multiple gas monitoring, making them practical for different applications as well as making sure that, if conditions change (such as sludge is stirred up, causing a sudden increase in hydrogen sulphide and flammable gas levels), the worker is still protected.  

Legislation   

European Commission Directive 2017/164 issued in January 2017, established a new list of indicative occupational exposure limit values (IOELVs). IOELV are health-based, non-binding values, derived from the most recent scientific data available and considering the availability of reliable measurement techniques. The list includes carbon monoxide, nitrogen monoxide, nitrogen dioxide, sulphur dioxide, hydrogen cyanide, manganese, diacetyl and many other chemicals. The list is based on Council Directive 98/24/EC that considers the protection of the health and safety of workers from the risks related to chemical agents in the workplace. For any chemical agent for which an IOELV has been set at Union level, Member States are required to establish a national occupational exposure limit value. They also are required to take into account the Union limit value, determining the nature of the national limit value in accordance with national legislation and practice. Member States will be able to benefit from a transitional period ending at the latest on 21 August 2023.  

The Health and Safety Executive (HSE) state that each year several workers will suffer from at least one episode of work-related illness. Although, most illnesses are relatively mild cases of gastroenteritis, there is also a risk for potentially fatal diseases, such as leptospirosis (Weil’s disease) and hepatitis. Even though these are reported to the HSE, there could be significant under-reporting as there is often failure to recognise the link between illness and work.  

Under domestic law of the Health and Safety at Work etc Act 1974, employers are responsible for ensuring the safety of their employees and others. This responsibility is reinforced by regulations. 

The Confined Spaces Regulations 1997 applies where the assessment identifies risks of serious injury from work in confined spaces. These regulations contain the following key duties: 

  • Avoid entry to confined spaces, e.g., by doing the work from the outside. 
  • If entry to a confined space is unavoidable, follow a safe system of work.
  • Put in place adequate emergency arrangements before the work start. 

The Management of Health and Safety at Work Regulations 1999 requires employers and self-employed people to carry out a suitable and sufficient assessment of the risks for all work activities for the purpose of deciding what measures are necessary for safety. For work in confined spaces this means identifying the hazards present, assessing the risks and determining what precautions to take. 

Our solutions

Elimination of these gas hazards is virtually impossible, so permanent workers and contractors must depend on reliable gas detection equipment to protect them. Gas detection can be provided in both fixed and portable forms. Our portable gas detectors protect against a wide range of gas hazards, these include T4x, Clip SGD, Gasman, Tetra 3,Gas-Pro, T4 and Detective+. Our fixed gas detectors are used in many applications where reliability, dependability and lack of false alarms are instrumental to efficient and effective gas detection, these include Xgard, Xgard Bright and IRmax. Combined with a variety of our fixed detectors, our gas detection control panels offer a flexible range of solutions that measure flammable, toxic and oxygen gases, report their presence and activate alarms or associated equipment, for the wastewater industry our panels include  Gasmaster.    

To find out more on the gas hazards in wastewater and water treatment visit our industry page for more information.  

Construction and Key Gas Challenges

Workers in the construction industry are at risk from a wide variety of hazardous gases including Carbon Monoxide (CO), Chlorine Dioxide (CLO2), Methane (CH4), Oxygen (O2), Hydrogen Sulphide (H2S) and Volatile Organic Compounds (VOC’s). 

Through the use of specific equipment, transport and the undertaking of sector specific activities, construction is a main contributor to the emission of toxic gases into the atmosphere, which also means construction personnel are more at risk of ingestion of these toxic contaminants. 

Gas challenges can be found in a variety of applications including building material storage, confined spaces, welding, trenching, land clearing and demolition. Ensuring the protection of workers within the construction industry from the multitude of hazards they may encounter is very important. With a specific focus on safeguarding teams from harm by, or the consumption of, toxic, flammable and poisonous gases. 

Gas Challenges 

Confined Space Entry 

Workers are more at risk from hazardous gases and fumes when they are operating within confined spaces.  Those entering these spaces need to be protected from the presence of flammable or/and toxic gases such as Volatile Organic Compounds (ppm VOC), Carbon Monoxide (ppm CO) and Nitrogen Dioxide (ppm NO2). Undertaking clearance measurements and pre-entry safety checks are paramount to ensure safety before a worker enters the space. Whilst in confined spaces gas detection equipment must be worn ongoingly in case of environmental shifts which make the space no longer safe to work in, due to a leak for example, and evacuation is needed. 

Trenching and Shoring 

During excavation works, such as trenching and shoring, construction workers are at risk of inhaling harmful gases generated by degradable materials present in certain ground types. If undetected, as well as posing risks to the construction workforce, they can also migrate through subsoil and cracks into the completed building and harm housing residents. Trenched areas can also have reduced oxygen levels, as well as contain toxic gases and chemicals. In these cases atmospheric testing should be performed in excavations that exceed four feet. There is also the risk of hitting utility lines when digging which can cause natural gas leaks and lead to worker fatalities. 

Building Material Storage  

Many of the materials used within construction can release toxic compounds (VOC’s). These can form in a variety of states (solid or liquid) and come from materials such as adhesives, natural and plywood’s, paint, and building partitions. Pollutants include phenol, acetaldehyde and formaldehyde. When ingested, workers can suffer from nausea, headaches, asthma, cancer and even death. VOCs are specifically dangerous when consumed within confined spaces, due to the risk of asphyxiation or explosion. 

Welding and Cutting 

Gases are produced during the welding and cutting process, including carbon dioxide from the decomposition of fluxes, carbon monoxide from the breakdown of carbon dioxide shielding gas in arc welding, as well as ozone, nitrogen oxides, hydrogen chloride and phosgene from other processes. Fumes are created when a metal is heated above its boiling point and then its vapours condense into fine particles, known as solid particulates. These fumes are obviously a hazard for those working in the sector and  illustrate the importance of reliable gas detection equipment to reduce exposure. 

Health and Safety Standards 

Organisations working in the construction sector can prove their credibility and safety operationally by gaining ISO certification. ISO (International Organisation for Standardisation) certification is split across multiple different certificates, all of which recognise varying elements of safety, efficiency and quality within an organisation. Standards cover best practice across safety, healthcare, transportation, environmental management and family. 

Although not a legal requirement, ISO standards are widely recognised as making the construction industry a safer sector by establishing global design and manufacturing definitions for almost all processes. They outline specifications for best practice and safety requirements within the construction industry from the ground up. 

In the UK, other recognised safety certifications include the NEBOSH, IOSH and CIOB courses which all offer varied health and safety training for those in the sector to further their understanding of working safely in their given field.  

To find out more on the gas challenges in construction visit our industry page for more information. 

The Dangers of Gas in Farming and Agriculture 

Farming and agriculture is a colossal industry the world over, providing more than 44 million jobs in the EU and making up over 10% of total US employment. 

With a wide range of processes involved in this sector, there are bound to be hazards that must be considered. These include gas hazards from the likes of methane, hydrogen sulphide, ammonia, carbon dioxide and nitrous oxide. 

Methane is a colourless, odourless gas which can have harmful effects on humans resulting in slurred speech, vision problems, memory loss, nausea and in extreme cases can impact breathing and heartrate, potentially leading to unconsciousness and even death. In agricultural environments, it is created through anaerobic digestion of organic material, such as manure. The amount of methane generated is exacerbated in areas which are poorly ventilated or high in temperature, and in areas with particular lack of airflow, the gas can build up, become trapped and cause explosions. 

Carbon dioxide (CO2) is a gas which is naturally produced in the atmosphere, levels of which can be heightened by agricultural processes. CO2 can be emitted by a range of farming process including crop and livestock production and is also emitted by some equipment which is used in agricultural applications. Storage spaces used for waste and grain and sealed silos are of particular concern due to the capacity for CO2 to build up and displace oxygen, increasing suffocation risk for both animals and humans alike. 

Similarly, to methane, hydrogen sulphide comes from the anaerobic decomposition of organic material and can also be found in a range of agricultural processes relating to the production and consumption of biogas. H2S prevents oxygen from being carried to our vital organs and areas where it builds up often have reduced oxygen concentrations, furthering the risk of asphyxiation where H2S levels are high. Whilst it could be considered easier to detect due its distinct ‘rotten egg’ smell, the intensity of the smell actually decreases at higher concentrations and prolonged exposure. At high levels, H2S can cause severe irritation of, and fluid build-up in the lungs and impact the nervous system. 

Ammonia (NH3) is a gas found in animal waste which is often then spread and emitted further through slurry spreading on agricultural land. As with many of the gases covered, the impact of ammonia is heightened when there is a lack of ventilation. It is harmful to the wellbeing of both livestock and humans, causing respiratory diseases in animals whilst high levels can lead to burns and swelling of the airways and lung damage in humans and can be fatal. 

Nitrogen oxide (NO2) is another gas to be aware of in the agriculture and farming industry. It is present in synthetic fertilisers which are often used in more intensive farming practices to ensure greater crop yields. The potential negative health impacts of NO2 in humans include reduced lung function, internal bleeding, and ongoing respiratory problems.  

Workers in this industry are frequently on the move, and for this specific purpose Crowcon offers a wide range of fixed and portable gas detectors to keep workers safe. Crowcon’s portable range comprises T4, Gas-Pro, Clip SGD and Gasman all of which offer reliable, transportable detection capacities for a variety of gases. Our fixed gas detectors are used where reliability, dependability and lack of false alarms are instrumental to efficient and effective protection of assets and areas, and include the Xgard and Xgard Bright. Combined with a variety of our fixed detectors, our gas detection control panels offer a flexible range of solutions that measure flammable, toxic and oxygen gases, report their presence and activate alarms or associated equipment, for the farming and agriculture industry we often recommend our Gasmaster, Vortex and Addressable Controllers panels.

To find out more on the gas hazards in farming and agriculture visit our industry page for more information.

The Dangers of Gas Exposure in Wineries

Wineries face a unique set of challenges when it comes to safeguarding workers from the potential harm caused by hazardous gases. Gas exposure has the potential to occur at every stage of the wine production process, from the moment that the grapes arrive at the winery facility, through to the fermentation and bottling activities. Care must be taken at each stage to ensure that workers are not exposed to unnecessary risk. There are several specific environments within the winery facility that pose a risk of gas leakage and exposure, including fermentation rooms, pits, barrel cellars, sumps, storage tanks and bottling rooms. The main gas hazards that are found during the winemaking process are carbon dioxide, and oxygen displacement, but also hydrogen sulphide, sulphur dioxide, ethyl alcohol and carbon monoxide.

What are the Gas Hazards?

Hydrogen sulphide (H2S)

Hydrogen sulphide is a gas that can be present during the fermentation process. It is more commonly present in damp conditions where bacterial action has acted on natural oils. It hides dissolved in standing water until disturbed. The most dangerous occurrence is when cleaning a confined space e.g., a tank where released gases cannot easily escape. A pre-entry check comes up clean, and the standing water is then disturbed upon entry. The risks associated with H2S are that it is potentially hazardous to health, upsetting breathing patterns. Hydrogen sulphide poses severe respiratory risks, even at a relatively low concentration in the air. The gas is very easily and rapidly absorbed into the bloodstream through the lung tissue, which means it is distributed throughout the whole body very quickly.

Sulphur Dioxide (SO2)

Sulphur Dioxide is a natural by-product of fermentation, but it is also commonly used as an additive in the process of organic wine making. Extra SO2 is added during the wine making process in order to prevent the growth of any undesirable yeast and microbes within the wine. Sulphur dioxide can be highly hazardous to health and is a highly toxic gas, causing numerous irritations in the body upon contact. Sulphur dioxide is a gas that can cause irritation to the airways, nose, and throat. Workers who are exposed to high levels of sulphur dioxide may experience vomiting, nausea, stomach cramps, and irritation or corrosive damage to the lungs and airways.

Ethanol (ethyl alcohol)

Ethanol is the main alcoholic product of organic wine fermentation. It helps to maintain the flavour of the wine and stabilizes the aging process. Ethanol is created during fermentation as the yeast converts sugar from the grapes. Wine typically contains somewhere between 7% and 15% ethanol, which gives the drink its alcohol by volume (ABV) percentage. The amount of ethanol actually produced depends on the sugar content of the grapes, the fermentation temperature, and the type of yeast that is used. Ethanol is a colourless and odourless liquid that gives off flammable and potentially hazardous fumes. The fumes given off by ethanol or ethyl alcohol can irritate the airways and lungs if inhaled, with the possibility of intense coughing and choking.

Where are the dangers?

Open Fermentation Tanks

Any worker whose job involves carrying out operations over an open fermentation vessel or tank may be at a high risk of gas exposure, especially to CO2, or oxygen depletion. It has been shown that a worker who leans over the top of an open fermenter during full production, even though they may be as much as 10 feet off the ground, can potentially be exposed to 100% CO2. Therefore, particular care and attention to gas detection should be taken in these areas.

Exposure Due To Inadequate Ventilation

The fermentation process needs to take place in environments that are well ventilated to avoid the build-up of toxic and asphyxiant gases. Fermentation rooms, tank rooms, and cellars are all places that may pose a risk. During cold weather or night-time, increased levels of gas may build up as door and window vents may be shut.

Confined Spaces

Confined spaces such as pits and sumps are often problematic and well known for the potential build-up of hazardous gases. The definition of a confined space in a winery is one that contains, or may contain, a hazardous atmosphere, has the potential for engulfment by material, or an entrant to the environment may become trapped or asphyxiated.

Multiple Units

As a winery grows and expands their operations, they may want to add new production units to meet the demand. However, it is important to remember that potential gas exposure risks differ between environments, e.g., the gas risk in a fermentation cellar is not the same as a barrel room. Therefore, different types of gas detectors may be needed in different areas.

For more information about gas detection solutions for wineries, or to ask further questions get in touch today.

Gold Mining: What gas detection do I need? 

How is gold mined?

Gold is a rare substance equating to 3 parts per billion of the earth’s outer layer, with most of the world’s available gold coming from Australia. Gold, like iron, copper and lead, is a metal. There are two primary forms of gold mining, including open-cut and underground mining. Open mining involves earth-moving equipment to remove waste rock from the ore body above, and then mining is conducted from the remaining substance. This process requires waste and ore to be struck at high volumes to break the waste and ore into sizes suitable for handling and transportation to both waste dumps and ore crushers. The other form of gold mining is the more traditional underground mining method. This is where vertical shafts and spiral tunnels transport workers and equipment into and out of the mine, providing ventilation and hauling the waste rock and ore to the surface.

Gas detection in mining

When relating to gas detection, the process of health and safety within mines has developed considerably over the past century, from morphing from the crude usage of methane wick wall testing, singing canaries and flame safety to modern-day gas detection technologies and processes as we know them. Ensuring the correct type of detection equipment is utilised, whether fixed or portable, before entering these spaces. Proper equipment utilisation will ensure gas levels are accurately monitored, and workers are alerted to dangerous concentrations within the atmosphere at the earliest opportunity.

What are the gas hazards and what are the dangers?

The dangers those working within the mining industry face several potential occupational hazards and diseases, and the possibility of fatal injury. Therefore, understanding the environments and hazards, they may be exposed to is important.

Oxygen (O2)

Oxygen (O2), usually present in the air at 20.9%, is essential to human life. There are three main reasons why oxygen poses a threat to workers within the mining industry. These include oxygen deficiencies or enrichment, as too little oxygen can prevent the human body from functioning leading to the worker losing consciousness. Unless the oxygen level can be restored to an average level, the worker is at risk of potential death. An atmosphere is deficient when the concentration of O2 is less than 19.5%. Consequently, an environment with too much oxygen is equally dangerous as this constitutes a greatly increased risk of fire and explosion. This is considered when the concentration level of O2 is over 23.5%

Carbon Monoxide (CO)

In some cases, high concentrations of Carbon Monoxide (CO) may be present. Environments that this may occur include a house fire, therefore the fire service are at risk of CO poisoning. In this environment there can be as much as 12.5% CO in the air which when the carbon monoxide rises to the ceiling with other combustion products and when the concentration hits 12.5% by volume this will only lead to one thing, called a flashover. This is when the whole lot ignites as a fuel. Apart from items falling on the fire service, this is one of the most extreme dangers they face when working inside a burning building. Due to the characteristics of CO being so hard to identify, I.e., colourless, odourless, tasteless, poisonous gas, it may take time for you to realise that you have CO poisoning. The effects of CO can be dangerous, this is because CO prevents the blood system from effectively carrying oxygen around the body, specifically to vital organs such as the heart and brain. High doses of CO, therefore, can cause death from asphyxiation or lack of oxygen to the brain. According to statistics from the Department of Health, the most common indication of CO poisoning is that of a headache with 90% of patients reporting this as a symptom, with 50% reporting nausea and vomiting, as well as vertigo. With confusion/changes in consciousness, and weakness accounting for 30% and 20% of reports.

Hydrogen sulphide (H2S)

Hydrogen sulphide (H2S) is a colourless, flammable gas with a characteristic odour of rotten eggs. Skin and eye contact may occur. However, the nervous system and cardiovascular system are most affected by hydrogen sulphide, which can lead to a range of symptoms. Single exposures to high concentrations may rapidly cause breathing difficulties and death.

Sulphur dioxide (SO2)

Sulphur dioxide (SO2) can cause several harmful effects on the respiratory systems, in particular the lung. It can also cause skin irritation. Skin contact with (SO2) causes stinging pain, redness of the skin and blisters. Skin contact with compressed gas or liquid can cause frostbite. Eye contact causes watering eyes and, in severe cases, blindness can occur.

Methane (CH4)

Methane (CH4) is a colourless, highly flammable gas with a primary component being that of natural gas. High levels of (CH4) can reduce the amount of oxygen breathed from the air, which can result in mood changes, slurred speech, vision problems, memory loss, nausea, vomiting, facial flushing and headache. In severe cases, there may be changes in breathing and heart rate, balance problems, numbness, and unconsciousness. Although, if exposure is for a longer period, it can result in fatality.

Hydrogen (H2)

Hydrogen Gas is a colourless, odourless, and tasteless gas which is lighter than air. As it is lighter than air this means it float higher than our atmosphere, meaning it is not naturally found, but instead must be created. Hydrogen poses a fire or explosion risk as well as an inhalation risk. High concentrations of this gas can cause an oxygen-deficient environment. Individuals breathing such an atmosphere may experience symptoms which include headaches, ringing in ears, dizziness, drowsiness, unconsciousness, nausea, vomiting and depression of all the senses

Ammonia (NH3)

Ammonia (NH3) is one of the most widely used chemicals globally that is produced both in the human body and in nature. Although it is naturally created (NH3) is corrosive which poses a serve concern for health. High exposure within the air can result in immediate burning to the eyes, nose, throat and respiratory tract. Serve cases can result in blindness.

Other gas risks

Whilst Hydrogen Cyanide (HCN) doesn’t persist within the environment, improper storage, handling and waste management can pose severe risk to human health as well as effects on the environment. Cyanide interferes with human respiration at cellular levels that can cause serve and acute effects, including rapid breathing, tremors, asphyxiation.

Diesel particulate exposure can occur in underground mines as a result of diesel-powered mobile equipment used for drilling and haulage. Although control measures include the use of low sulphur diesel fuel, engine maintenance and ventilation, health implication includes excess risk of lung cancer.

Products that can help to protect yourself

Crowcon provide a range of gas detection including both portable and fixed products all of which are suitable for gas detection within the mining industry.

To find out more visit our industry page here.

How do Electrochemical sensors work? 

Electrochemical sensors are the most used in diffusion mode in which gas in the ambient environment enters through a hole in the face of the cell. Some instruments use a pump to supply air or gas samples to the sensor. A PTFE membrane is fitted over the hole to prevent water or oils from entering the cell. Sensor ranges and sensitivities can be varied in design by using different size holes. Larger holes provide higher sensitivity and resolution, whereas smaller holes reduce sensitivity and resolution but increase the range.  

Benefits  

Electrochemical sensors have several benefits.  

  • Can be specific to a particular gas or vapor in the parts-per-million range. However, the degree of selectivity depends on the type of sensor, the target gas and the concentration of gas the sensor is designed to detect.  
  • High repeatability and accuracy rate. Once calibrated to a known concentration, the sensor will provide an accurate reading to a target gas that is repeatable. 
  • Not susceptible to poisoning by other gases, with the presence of other ambient vapours will not shorten or curtail the life of the sensor. 
  • Less expensive than most other gas detection technologies, such as IR or PID technologies. Electrochemical sensors are also more economical. 

Issues with cross-sensitivity  

Cross-sensitivity occurs when a gas other than the gas being monitored/detected can affect the reading given by an electrochemical sensor. This causes the electrode within the sensor to react even if the target gas is not actually present, or it causes an otherwise inaccurate reading and/or alarm for that gas. Cross-sensitivity may cause several types of inaccurate reading in electrochemical gas detectors. These can be positive (indicating the presence of a gas even though it is not actually there or indicating a level of that gas above its true value), negative (a reduced response to the target gas, suggesting that it is absent when it is present, or a reading that suggests there is a lower concentration of the target gas than there is), or the interfering gas can cause inhibition. 

Factors affecting electrochemical sensor life  

There are three main factors that affect the sensor life including temperature, exposure to extremely high gas concentrations and humidity. Other factors include sensor electrodes and extreme vibration and mechanical shocks. 

Temperature extremes can affect sensor life. The manufacturer will state an operating temperature range for the instrument: typically -30˚C to +50˚C. High quality sensors will, however, be able to withstand temporary excursions beyond these limits. Short (1-2 hours) exposure to 60-65˚C for H2S or CO sensors (for example) is acceptable, but repeated incidents will result in evaporation of the electrolyte and shifts in the baseline (zero) reading and slower response.  

Exposure to extremely high gas concentrations can also compromise sensor performance. Electrochemical sensors are typically tested by exposure to as much as ten-times their design limit. Sensors constructed using high quality catalyst material should be able to withstand such exposures without changes to chemistry or long-term performance loss. Sensors with lower catalyst loading may suffer damage. 

The most considerable influence on sensor life is humidity. The ideal environmental condition for electrochemical sensors is 20˚Celsius and 60% RH (relative humidity). When the ambient humidity increases beyond 60%RH water will be absorbed into the electrolyte causing dilution. In extreme cases the liquid content can increase by 2-3 times, potentially resulting in leakage from the sensor body, and then through the pins. Below 60%RH water in the electrolyte will begin to de-hydrate. The response time may be significantly extended as the electrolyte or dehydrated. Sensor electrodes can in unusual conditions be poisoned by interfering gases that adsorb onto the catalyst or react with it creating by-products which inhibit the catalyst. 

Extreme vibration and mechanical shocks can also harm sensors by fracturing the welds that bond the platinum electrodes, connecting strips (or wires in some sensors) and pins together. 

‘Normal’ life expectancy of electrochemical Sensor  

Electrochemical sensors for common gases such as carbon monoxide or hydrogen sulphide have an operational life typically stated at 2-3 years. More exotic gas sensor such as hydrogen fluoride may have a life of only 12-18 months. In ideal conditions (stable temperature and humidity in the region of 20˚C and 60%RH) with no incidence of contaminants, electrochemical sensors have been known to operate more than 4000 days (11 years). Periodic exposure to the target gas does not limit the life of these tiny fuel cells: high quality sensors have a large amount of catalyst material and robust conductors which do not become depleted by the reaction. 

Products  

As electrochemical sensors are more economical, We have a range of portable products and fixed products that use this type of sensor to detect gases.  

To explore more, visit our technical page for more information.