Toxic Gas Hazards in the Brewery Industry | Air-Met Scientific
Brewing beer is an art and a science. The science of brewing beer is the process of how the four main ingredients of crafting beer: water, malt, hops and beer yeast, come together to make this alcoholic beverage.
The brewing process produces odourless and colourless asphyxiant gases that can potentially harm those working in underground cellars and cool rooms. These locations are also often enclosed and non-ventilated, leading to a higher risk of asphyxiation. Despite the known hazards of the asphyxiant gases in breweries, many businesses fail to implement the correct safety measures to mitigate the risk resulting in tragic and avoidable accidents in the workplace.
Toxic Gas Hazards in Breweries and their Effects
Gas hazards in breweries range from carbon dioxide during the fermentation process, ammonia from refrigeration leaks and and methane from brewery wastewater. The following are the common gas hazards in breweries:
Carbon Dioxide (CO2) - Carbon dioxide is a by-product of the fermentation of beer, CO2 recovery and the carbonation process. Due to its molecular density, CO2 gas typically collects at the bottom of confined spaces including in tanks and cellars which could leak and sink in the floor. When it sinks into the floor, it creates invisible pockets. CO2 is present in breweries from brewing to the packaging process.
CO2 is considered a hazard at as little as 0.5% and it is lethal when more than 10% of the composition of air. Excessive carbon dioxide exposure can cause dizziness, vomiting, shortness of breath and even death (3000.000 ppm, 30% CO2)
Ammonia (NH3) - Due to its energy-efficient and non-polluting properties, ammonia is a popular gas for refrigeration, processing and bottling in breweries, wineries, dairy and soft drink production. However, ammonia is also a corrosive and highly reactive gas that can pose a significant risk to workers if there are leaks in the refrigeration and bottling areas. Even at the lowest level (0-25 ppm) ammonia can cause skin, eye and lung irritation in workers. At higher levels (50 ppm of NH3), ammonia exposure can cause pulmonary oedema (a condition caused by excess fluid in the lungs).
Methane (CH4) and Hydrogen Sulphide (H2S) - Brewery wastewater is high in organic content. Anaerobic digestion is a popular method used to minimise the impact on municipal wastewater. Biogas is the primary by-product of this process. Biogas consists of CO2, CH4 and H2S. High levels of methane and hydrogen sulphide can reduce the amount of oxygen in the air. Oxygen deficiency can cause slurred speech, nausea and vision problems among the many other side effects.
Safety Precautions and Best Practices to Minimise Gas Hazard Risks in Breweries
As a precaution, the areas with a high risk of hazardous gases should only be entered by employees and qualified personnel when necessary. Employers are also responsible for assessing the risks these areas pose and undertake measures to eliminate them such as a written respiratory protection program, confined space entry programs and adequate training for employees on how to manage a gas hazard risk.
The concentration of gases in an area can be measured using a fixed or portable gas monitor. A fixed gas monitor such as the ZyAura Wall Mount CO2 Fixed Gas Monitor will activate an audible and visual alarm when the concentration of CO2 reaches a pre-set level in the room. The default alarms on the ZyAura are set at 1.5% low alarm and 3% high alarm. It will also produce a trigger to activate the fans in the room to ventilate the confined space and reduce the concentration of CO2. The advantage of using a fixed gas monitor is it can remotely monitor a work area for 24 hours without being recharged. It can also beintegrated to other reporting and monitoring systems such as BMS (Building Management Systems) or SCADA ( Supervisory control and data acquisition).
Portable gas detectors such as the Industrial Scientific Ventis MX4 Portable Multi-Gas Monitor are a suitable solution for confined spaces that cannot accommodate a fixed gas detector. Portable gas monitors are ideal for confined space entry to assess for hazardous gases before a worker enters the space. Multiple gas monitors like the Ventis MX4 or the Ventis Pro5 are also suitable for measuring multiple toxic gases at the same time. The disadvantage of a portable gas monitor is that is needs to be fully charged before use and it has a defined run time.
Different Australian states have varying work, health and safety regulations while working with hazardous gases and chemicals. For example, WorkSafe Victoria specifies in its guidance document, AS5034-2005, Installation and use of inert gases for beverage dispensing, the mitigation steps to be taken in breweries and wineries if the gas cylinders are located in a confined space.
Having the appropriate measures can ensure workers are not injured from asphyxiant toxic gases in breweries and the brewing plants are compliant to work, health and safety regulations. A reliable and well-maintained gas monitor, fixed or portable could mean the difference between life or death.
