Nearly every workplace stocks and makes use of chemicals, from the cleaning solutions kept under the washroom sink to the products used in industrial processes.
What those substances are and which hazards they pose will vary wildly, but the majority will fall into a few basic categories. Knowing the common usage guidelines for each of these types will help you ensure that the chemicals on your worksite are stored and handled safely.
Before getting to those details, however, let's take a moment to talk about Safety Data Sheets (SDS).
Safety Data Sheets
A Safety Data Sheet is a document that outlines the critical safety information for a chemical product. It will include instructions for safe handling and storage, the potential routes of exposure, and the hazards associated with the product. The SDS will also specify the permissible exposure limit (PEL). OSHA specifies a PEL for approximately 500 different substances, indicating how much exposure is generally be considered safe.
While there are general safety guidelines you can follow with various types of chemical products, make sure you have an SDS for each chemical product on the worksite and consult them to know exactly what you're dealing with.
(For more information, check out Everything You Need to Know About Safety Data Sheets)
With that out of the way, let's look at six types of chemicals that are common across many different worksites and basic recommendations for their use.
Compressed Gases
Compressed gases can describe anything from oxyacetylene, propane, and oxygen bottles all the way down to something as pedestrian as spray paint. Any substance that contains a propellant or is compressed into a canister falls into this category, because all of them can explode and cause fires under certain conditions.
The finer points of handling each of these chemicals will be found in the Safety Data Sheet. Acetylene, for example has a litany of special considerations, such as the risk of accumulated “carbon black,” decomposition reaction from mechanical shock to the cylinders, and the risk of unintended ignition.
The general guidance for compressed gases is to ensure that they are not exposed to excessive heat. Allowing cylinders to become overheated increases the pressure within, and while these cylinders have pressure release devices there are limitations to what they can do.
It is advisable not to store compressed gases next to other flammable materials. It is also important not to store oxidizers (such as peroxides or compressed oxygen) with flammable compressed gases, since this can be a deadly combination in the event of a fire. The fuel combines with oxygen to produce an energetic flame that can easily get out of control and is able to sustain itself.
(Learn more about the Important Dangers of Handling Acetylene Gas)
Cleaning Products, Disinfectants, Detergents, and Solvents
Cleaning products come in various types, as well. They range from benign and questionably effective citric acid mixes all the way up to organic solvents like Toluene or Xylene. It all depends on the mess a given worksite has to deal with – coffee stains and bitumen call for different cleaners!
Most cleaning products act as solvents, so you don’t want to get them on your hands. Solvents “de-fat” skin, meaning they dissolve dermal lipids in the skin and desiccate it, causing (potentially chronic) dermatitis. Some like styrene and benzene may even enter through the skin and have the potential to cause cancer.
Hydrocarbons that are effective at degreasing or solving (e.g. Toluene, Styrene, methyl ethyl ketone) also tend to be energetically flammable. These hydrocarbons can be extremely effective, but need to be handled with extreme care.
Even among common consumer cleaning products, there are significant hazards to consider. For example, mixing ammonia and chlorine yields chloramine gas. Alcohol and bleach produce chloroform. Mixing bleach with an acid such as vinegar produces chlorine gas (a substance so noxious that its use in war is banned by the Geneva Protocol!) which then combines with water (such as in your eyes and mouth) to produce hydrochloric acid.
Basically, the take-home message is: don’t mix bleach with anything or you’re going to have a bad time.
Paints and Coatings
Inhalation is the main concern with paints and coatings, especially those that are applied by spraying. Sprayers disperse droplets of paint that spray in every direction, so the workers applying it and anyone in the vicinity need to be protected.
The paint or coating itself is often not the key concern. These substances are usually dissolved in a solvent to keep them in a usable liquid form. That solvent evaporates in a normal atmosphere, but if you are close by when that happens, you may be inhaling it or at risk of accidentally igniting it when it mixes with the air.
That latter point is important to understand. In an unventilated space, it is possible to reach the Lower Explosive Limit (LEL) and create a serious fire risk if any sources of ignition are present. It only takes a single spark to set it off.
Additionally, some types of industrial paint are known sensitizers that can cause potentially severe allergic reactions after repeated exposure. This can even occur across different, related chemicals and can become a chronic condition.
Fuels
Basic fuels like gasoline and diesel are common on all sorts of worksites. If a company maintains any vehicles or powered mobile equipment, they probably have to handle or storage these substances for refueling.
The key factors are how to prevent exposure, how to avoid fires, and how to deal with spills. Any amount that spills on the ground needs to be cleaned up because these chemicals can accumulate and make their way into groundwater or waterways.
A fuel's function is facilitated by its ability to combust. That's what makes them useful, but also dangerous. Because of that, certain situations will require proper grounding/bonding. If fuel is being decanted from one container to another, a voltage potential can develop between the two containers just by the action of fuel moving through a hose. If this were to discharge, it could cause a spark that can ignite the vapors.
The Safety Data Sheet can provide information on how to handle specific fuels, and how flammable they are which all informs whether special measures are necessary.
(Find out How to Prepare for Chemical Spills in the Workplace)
Byproducts
Some of the substances that workers can be exposed to don't come with conveniently labelled bottles and detailed Safety Data Sheets. That's because they're the exhaust products of other processes. They can, nonetheless, cause harm if not carefully considered.
The most significant and common byproduct is probably carbon monoxide (CO). It is produced in virtually any kind of combustion and can be very hazardous to health. Unlike other asphyxiants, CO is a chemical asphyxiant, meaning it binds to hemoglobin and prevents oxygen transfer – essentially suffocating someone at a cellular level. CO won't make its presence know; it is odorless, tasteless, colorless, and marginally lighter than air so that it diffuses throughout spaces. If there is a potential carbon monoxide risk, a gas monitor will be needed to detect it in the atmosphere.
Carbon dioxide (CO2) is another common byproduct of combustion, but one that poses a different kind of hazard. It is heavier than air, and thus settles into low lying spaces or displaces the breathable air from confined spaces. It is not a chemical asphyxiant like carbon monoxide, but can render a space oxygen deficient. This is one of the reasons a confined space's atmosphere is tested before anyone is permitted to enter.
(Learn more about The Dangers of Gas in a Confined Space)
Silica and Asbestos
Working with asbestos is not for amateurs. It is a very specialized task. However, while few people actually work with asbestos, millions work around it without even knowing.
Asbestos is present in many older buildings as insulation, in drywall, in tiles, and used as pipe covering. It is estimated to cause over a quarter-million deaths a year worldwide, of which over 90 percent are work-related.
Asbestos is treated with an abundance of caution whenever it is detected. When its presence is suspected, we test materials before proceeding with any operation, such as demolition, that may upset the material and introduce it to the air. But generally, asbestos is harmless as long as it is left alone.
Silica is less understood and still often overlooked. It may not be the juggernaut that asbestos is, but in 2019 it still claimed almost thirteen thousand lives worldwide. And those are just the ones we know about. It’s suspected that it could contribute to a much greater number of cases, but it hasn’t been on our radar as long.
Unfortunately, many jobsites still haven't caught up to the risks. It’s not uncommon to see concrete saws sending up huge plumes of dust while the operator isn't even wearing a dust mask. Or they are, but they’re blasting dust into a site full of people with no protection. It’s also common to see drywallers with lines of dust traced up to their nostrils, where silica-containing joint compound or drywall dust has found its mark.
Inhalation of crystalline silica can lead to a specific sub-form of pneumoconiosis called silicosis. It may not kill as many people as asbestos, but silica is suspected to contribute to a good number of deaths and disabilities from chronic pulmonary conditions. For that reason, proper respiratory protection is critical for any worker who may be at risk of inhaling it.
(Learn more about Detecting, Sampling, and Measuring Silica on Your Job Site)
Stay Safe
Hazardous chemicals are unavoidable. Every workplace has them and some jobs can't be done without frequently making use of them.
That's why it's important to have procedures for safely handling and storing chemicals. Workers should also be trained in how to use them and be supplied with any personal protective equipment (PPE) that may be required.
When in doubt, remember that you can always consult the Safety Data Sheet.