With the global proliferation of calibration gas, it is vital to understand the health hazards associated with the product. Specialty gas can either be pure or a mixture of gases that is tested for purity after filling the cylinder. These gases have become essential components for myriads of industries such as semiconductors, chemicals, food, medical, environmental, biotechnology, materials processing, and more.
The demand for the product continues to plummet, and it is predicted that the worldwide specialty gas sector will be worth more than $14 billion by 2026. The gases are available in various grades, including high purity, ultra-purity, and research-grade. Calibration gases present certain dangers and risks, while some are even considered as prospect chemical weapons. Here are some hazards associated with specialty gases.
A flammable gas needs an oxidizer and an ignition source to burn. For the gas to burn, the mixture with the oxidizer should be within the flammable limits range, which are the upper flammability limit and lower flammability limit. Some gases are not considered flammable but can burn under specific ambient conditions during transportation.
Some gases can explode when released in the presence of an ignition source like static electricity or heat source. The rupture is usually caused by the sudden rise in pressure. Other flammable gases ignite if let out into the atmosphere because they have an auto-ignition temperature of less than 130 degrees.
One of the most typical routes of exposure to toxic gas is inhalation, while absorption through the skin is a rare one. When some of these specialty gases are inhaled, they can cause adverse effects, including death. Some gases such as arsine can result in rapid death, deterioration of health from toxins accumulation, while others like nitrous oxide can cause damage to vital tissues.
Any gas or mixture, when released into a constricted space, can displace oxygen to concentrations below the life-sustaining levels. Some gases have a higher density than air, especially those below atmospheric temperatures and can flow to low-lying areas such as basement rooms, wells, sewer utility holes, pump sumps, and more. Furthermore, gases like hydrogen and helium have a lower density than air and can accumulate in spaces, for example, ceiling and attic.
Tragic accidents due to asphyxiation have resulted from incidents such as leaks from hoses or calibration gas cylinders, inadequately isolated process lines, entry into confined spaces, and spillage from dewars. Most cases have been associated with inert gases because they are colorless and odorless hence undetectable. Oxygen monitoring equipment can help reduce these incidents, mainly where inert gases are being used in enclosed areas.
Specialty gas can cause chemical burns if it is corrosive, leading to the rapid destruction of human tissues. Some gases are dangerous when they come in contact with moisture or human organs like eyes and mouth. In dry conditions, these gases have less significant effects on metals. However, in case of any leak, corrosive gases can mix with the atmospheric moisture and corrode valves, metal containers, and fittings.
High Gas Pressure
Gases under pressure can be hazardous because of the massive difference in energy gradient with that of the atmospheric pressure. Calibration gases stored in high pressure can lead to severe injury or damage when released accidentally. Equipment failure or human error can cause gas leaks. Some unusual incidents like fire or any strain exerted on the container wall can exceed the rupture strength of the cylinder causing it to explode.
Safety Handling Tips and Procedures
It is advisable to know the weight of specialty gas, especially the flammable ones. The weight can determine whether to have oxygen monitoring equipment or not. Personal protective equipment such as safety glasses, flame-retardant clothing, gloves, and safety shoes are required when handling custom calibration gas. Moreover, never store disposable gas cylinders in extreme temperature conditions, and near corrosive materials or ignition sources.
Specialty gas has an eclectic mix of uses from analytical methods to environmental and electrical uses. However, these gases are hazardous because of their inherent physical, biological, and chemical properties, as well as reactivity. Calibration gases should be handled with extra care because they can cause physical, environmental, chemical and health hazards.