An Introduction to Hazardous Waste Class-5 Oxidizers
April 1, 2020
Oxygen is still legal, even in the state of California.
This is a good thing, as without it carbon-based lifeforms wouldn’t exist. And since all of us are carbon-based lifeforms—even your dog, goldfish, hyacinth, and in-laws—it’s good to have a lot of the stuff around.
But not too much.
Oxygen is not combustive in and of itself. Instead, it supports oxidation, which is useful under controlled circumstances. Too much oxygen in one place can have incendiary and/or explosive consequences.
Chemically speaking, oxidation is a process by which one atom, compound, or molecule loses electrons to another atom, compound, or molecule. Non-chemically speaking, we call it “fire” if the process is rapid and “rust” if it’s slow.
As you might guess, it’s the “fast” variety that holds the peculiar interest of federal, state, and local authorities—which brings us to the hot topic of oxidizers.
What exactly is an oxidizer?
An oxidizer is anything that can start and support a fire through oxidation. Called Class5 Hazardous Wastes per the Department of Transportation (DOT), it’s a category divided into two subsets:
- Class 5.1 oxidizers are materials, which by yielding oxygen, can cause or enhance the combustion of other materials. Loosely speaking, they’re catalysts to setting something else on fire—whether to good or bad effect.
- Class 5.2 oxidizers are organic peroxides that contain everything necessary to cause a fire on their own, which they have a propensity to do. They’re used as chemical accelerators, activators, catalysts, curing agents, hardeners, and more.
In case of any accident involving a Class-5 oxidizer
You should have a Safety Data Sheet (SDS) for each oxidizer you have onsite, which will cite specific procedures for the particular chemical. But in general:
Skin contact: Remove contaminated clothing, rinse the affected area with lots of water—usually for 15 minutes or until pain ceases. Seek medical attention.
Eye contact: Rinse thoroughly with eyewash for at least 15 minutes, rolling eyeballs and occasionally lifting upper and lower eyelids. Seek medical attention.
Inhalation: Move to fresh air. Breathe deeply. Seek medical attention.
Ingestion: Rinse the mouth with water. Don’t induce vomiting. Seek medical attention.
Dry spills: Carefully sweep a solid oxidizer into a dustpan and place it into a container with a lid.
Liquid spills: These require inert absorbent pads, which are free of organic materials. Acidic oxidizers must first be neutralized with sodium bicarbonate.
Does your business have Class 5.1 oxidizers onsite?
You might be surprised. Typical Class 5.1 oxides are:
- Potassium bromate: Commonly used to improve flour, strengthening the dough to allow higher rising
- Sodium hypochlorite: The main ingredient in household bleaching and pool-maintenance products, also used in the textile, detergent, oil refinery, and paper and pulp industries
- Ammonium nitrate: Used to produce fertilizers, antibiotics, yeasts, and of particular interest to the current conversation: explosives
- Potassium nitrate: Most notably used for fertilizers, rocket propellants, fireworks, gunpowder, and we can’t resist reporting: tree-stump removal
- Nitric acid: Used in in the production of ammonium nitrate for producing fertilizers, dyes, certain plastics—and (again) explosives such as nitroglycerin and TNT
- Halogens: Named from the Greek roots hal- (“salt”) and -gen (“to produce”), because each produces a salt. These are fluorine, chlorine, bromine, iodine, astatine, and tennessine, which are important to the chemical, water and sanitation, plastics, pharmaceutical, pulp and paper, textile, and oil industries (BTY, common table salt is a halogen)
Let’s talk about Class 5.2 oxidizers
If you have this stuff onsite, you probably already know it—or you should know it. Among their most unlovable features are thermal instability, a tendency for self-accelerating decomposition, sensitivity to impact or friction, and dangerous reactions with other substances.
Direct exposure to organic peroxides can cause eye, skin, and respiratory irritation. Add to that nausea, stupor, and/or vertigo—and to say that organic peroxides can present hazardous workplace conditions is an exercise in understatement. Among these chemical bad actors are:
- Diacetyl peroxide: A white-solid or oily-liquid with a sharp odor that’s often used as a solvent
- Acetozone: A strong oxidant historically used as a surgical antiseptic and a bleaching agent for flour
- Acetyl Acetone Peroxide: Used to cure unsaturated polyester resins
- Ascaridole: Unstable and prone to explosion when heated or treated with organic acids, it’s a component of Latin American natural medicine, tonic drinks, and food flavorings. (Ole!)
- Methyl ethyl ketone peroxide: Used in industry (and by hobbyists) as a catalyst for turning polyester into fiberglass and castings
Methyl ethyl ketone peroxide: A hardening agent for fiberglass-reinforced plastics and used in the manufacture of polyester and acrylic resins
General hazmat management concerns for oxidizers
What would otherwise be a nonevent under most circumstances can become a major workplace inferno in the presence of oxidizers. (Please note: OSHA frowns on workplace major infernos). That said:
- Employees should be familiar with the relative reactivity of whatever chemicals they’re using, as mixing an overly-robust oxidizer with an organic chemical can result in a violent reaction.
- Any unused excess of an oxidizer should never be returned to its virgin container, as it might have become incidentally contaminated with other chemicals and thereby elicit an unwanted and dangerous reaction.
- Standard laboratory attire should be required for anyone handling oxidizing chemicals, which means lab coats, rubber gloves, closed-toe shoes, long pants, safety glasses, splash goggles, etc.
- And in case things go south real fast, they should also accessorize their standard laboratory attire with a chemical fume hood to shield their faces from any unfortunate fire and flame.
Disposal of Class-5 oxidizers
Here’s one of those occasional places where we feel compelled to remind our readership that it’s imperative to get expert advice, as disposal of oxidizers involves a lot of science, a bit of art, and bears the scrutiny of the EPA, DOT, and a multitude of state and local authorities.
Generally speaking, all EPA “cradle-to-grave” requirements for the generation, transportation, storage, and disposal of hazardous waste are applicable to Class-5 oxidizers, including the need for sealed, strong, leakproof containers that are properly labeled.
But additionally, you need to be vigilant that oxidizers are stored and/or transported, as my uncle use to say, nowhere near nothin’ that might be flammable, such as paper, wood, or spent oils, any of which might be encouraged to spontaneously combust in the presence of elevated oxygen levels.
The upshot
Because oxidizers can be reactive, you should seek expert advice about their storage, transportation, and disposal.
Hiring a properly licensed and qualified waste disposal specialist lessens your exposure to legal liabilities relative to EPA cradle-to-grave requirements; minimizes onsite and environmental risks; and helps ensure that you’re in compliance with government regulations, which tend to be in dynamic and abundant supply.