Proper Storage of Chemical and Hazardous Materials
Many construction sites store chemical and hazardous materials onsite. Jobsites may house anything from acids and other caustic substances, to paints and glues, to heavy metals, solvents, or volatile liquids. While the types of substances jobsites have may differ, the one thing they have in common is the necessity to store and handle all materials safely and securely.
The number one issue with storage of chemicals or hazardous materials is safety. Whatever containment or storage solutions are utilized must be able to hold the materials adequately and be safe from unauthorized use, potential damage, and fire. Depending upon the material, potential hazards can include fire, explosion, release of toxic vapor or gas, and spills. Storing and handling chemical or hazardous materials properly can mitigate these hazards and there are many products that assist with storing materials with safety in mind.
How to Store Chemicals and Hazardous Materials
When storing chemicals at work, they must be accessible and stored properly to protect people and property. OSHA and the National Fire Prevention Association (NFPA) regulate chemical storage in various industries, including construction.
Keeping chemicals away from the risk of fire is of paramount concern. OSHA and NFPA categorize flammable chemicals by their flashpoints or the lowest temperature at which a liquid can form an ignitable mixture with air. Safe handling and storage of chemicals categorized in these OSHA and NFPA classifications is required. The requirements that protect from potential fire regulate how much can be stored in a specific container and the types of approved storage.
Another important factor in storing chemicals is knowing how they react with other chemicals also being stored onsite. It is vital to keep hazardous chemicals away from any incompatible materials. This requires a detailed knowledge of what chemicals are being stored onsite and proper identification and labeling of containers and storage cabinets.
Chemicals must be stored in compliance with OSHA and NFPA codes and regulations and companies can face OSHA fines for not complying. Finally, it is important to store chemicals and hazardous materials in OSHA-approved, specially designed, containers and cabinets on the job. It is the best way to keep employees and property safe and secure.
Safety and Storage Cans
Safety cans are used when storing hazardous chemicals or when transferring a hazardous liquid. There are many types of liquid storage containers and cans in which to store (and dispose of) chemicals on the job. Their use is OSHA required and flammable liquids can safely be stored in approved safety cans. OSHA definition of a safety can:
“Safety can shall mean an approved container, of not more than 5 gallons capacity, having a spring-closing lid and spout cover and so designed that it will safely relieve internal pressure when subjected to fire exposure.”
Safety cans are fire safe and control flammable vapors. They have a leakproof lid that protects vapors from escaping. A flammable liquid in and of itself is not volatile but its vapors are, so prohibiting vapors from emitting is important in preventing fires or explosions. Safety cans are 100% leakproof, have flame arresters, self-closing lids, and pressure relief. They all contain a yellow band on the outside that contains safety information and a place to display the contents.
Types of Safety Cans
There are several types of OSHA-approved safety cans. Type I Safety Cans are used to transport or store flammable liquids, including gas, and are the most widely used cans. Type I Safety Cans have a single spout for filling and pouring.
Type II Safety Cans have two openings: one, like Type I cans, for filling and another equipped with a flexible, metal spout for accurate pouring.
Type II – D.O.T. Transport
A Type II DOT Safety Can has all the features of a Type II and includes a roll bar for over the road transport. These safety cans are used for commercial vehicles that transport hazardous chemicals on the roadways. The roll bar construction provides an added layer of protection when transporting hazardous contents.
Materials and Color Coding
While most safety cans are made from metal, there are nonmetallic cans made from polyethylene that are resistant to corrosive chemicals. They are durable, dent resistant, and can be used in construction.
What’s in the safety can matters, therefore, it is vital to use the correct can for the contents. Red cans are most widely used. OSHA requires flammable liquids with a flashpoint below 80 Fahrenheit to be in a red can, typically they are used for gasoline. Additionally, yellow cans are used to store diesel oil, blue cans are to store kerosene, and green cans for oil.
When storing large volumes of flammable liquids on the job, drums should be used. Drums containing bulk storage of liquids should be properly grounded or bonded to prevent static discharge which could ignite vapor when dispensing liquid. Typically, liquids would be transferred from the large drum into safety cans using the gravity flow method or pump method.
The gravity flow method is the transfer of liquid from a drum situated in the horizontal position. Using a safety faucet, the liquid is dispensed via a safety drum vent in the drum. The pump method is used for vertically stored drums and the liquid is pumped from the drum to the safety can, with a safety vent inside the drum. Both methods can be dangerous and proper grounding and bonding must occur to prevent vapor ignition.
Safety and Storage Cabinets
To keep jobsites from being littered with safety cans of flammable liquids, contractors store them in approved safety cabinets. Specially designed cabinets are built to store flammable fuels, chemicals, paint, solvents, aerosols, etc., and help businesses remain in compliance.
Effective cabinets are OSHA and NFPA-compliant and protect chemicals from fire and other dangers. The real benefit to a safety cabinet is its fire protection. Chemicals can be safely stored on a worksite because the cabinet protects the contents. Approved safety cabinets must pass a standard 10-minute fire test where the internal temperature of the cabinet will remain below 325 Fahrenheit despite the fire’s heat.
Safety cabinets are brightly colored—often yellow—and have visible labeling indicating what is inside. This labeling typically includes a warning that says “Flammable – Keep Fire Away.” The outside label is reflective in case of smokey conditions or a power outage. The cabinets come in all shapes and sizes; they can hold large drums or multiple safety cans.
Typical safety features of a safety cabinet include:
- Highly reflective signage on outside reading “Flammable – Keep Fire Away”
- Flush handles that can be used with keys or padlocks
- Slightly slopped shelves that direct any spills to the back and bottom of cabinet
- Built-in, 2-inch sump to contain any leaks or spills
- Thick, double wall steel construction
- Adjustable leveling for outer feet to accommodate uneven surfaces
- Built-in grounding features
- 3-point latching system with self-closing doors
One important element of safety cabinets is the consistent closing of the doors by workers and people who use the cabinets. Manual close doors permit a 180-degree opening but require the user to effectively shut the doors after use. They do have a built-in safety mechanism whereby if a fire breaks out and the doors are left open the manual doors have fusible links that melt when the ambient temperature reaches 165 Fahrenheit. The doors will slam shut when the links melt and a self-latching engages ensuring a fire-proof seal for the cabinet’s contents.
Self-close doors have a mechanism in the top wall of the cabinet that ensures the doors are closed after each use, even when users forget. This is the preferred door choice because it provides an extra layer of safety.
There are caveats when it comes to venting safety cabinets. The vapors that could emanate from a cabinet are not safe inside or outside of the cabinet and venting vapor out of the cabinet presents risk. NFPA 30 does not require that safety cabinets be vented for fire protection, although many do include dual vents with flame arrestors. Proper safety practices suggest that the local Fire Marshall inspect workplace or jobsite cabinets to determine whether and how to vent a particular cabinet.
Additional Safety Measures
Since safety cabinets store flammable chemicals, grounding makes good safety sense, particularly if liquid dispensing occurs from the cabinet. Errant vapors can ignite from built up static in drums, cans, or containers, therefore, proper grounding and bonding are essential. Inside the cabinet, slightly sloped shelves direct any spills downward to the cabinet sump and prevent pooling on the shelf surface. Safety cabinets should be fastened to walls with mounting brackets in areas where earthquakes or hurricanes occur.
Safety Cabinet Don’ts
- Even though the cabinet may have been situated in place on top of a pallet, it is important to remove the pallet from below the cabinet. Not only is it out of compliance with OSHA regulations if left on a pallet, it presents a host of other problems. Sitting atop a pallet prevents the cabinet from sitting level on the floor and could prevent proper grounding and the prevention of static build up. In case of fire, a wooden pallet serves as fuel directly below the cabinet; the cabinet would surely topple over if the pallet burned.
- Ensure the placement of a safety cabinet does not impact workers exiting a building in case of fire or another emergency.
- Also, they should not be placed under stairs.
- Don’t locate a safety cabinet too close to electrical outlets and panel boards.
- Avoid conducting grinding, welding, or cutting too close to cabinets as these activities could ignite vapors.
- It goes without saying that smoking is prohibited near safety cabinets.
Chemicals and other hazardous materials are ubiquitous in construction. Not only are there chemicals in many building materials, but all types of jobsite require the use of chemicals to get the job done. Be sure all chemicals and hazardous materials are stored safety and securely with the proper safety can or cabinet.