Hazardous Materials Classification Compliance: Getting The Basics Right So Everything Else Works

Classification is the first domino

When you decide to ship batteries, sealants, aerosols, generators, cleaners, or coatings, you might think packaging or carriers are your first big decisions. In reality, everything starts one step earlier. Hazardous materials classification compliance is the first domino. If you get it wrong, every decision that depends on it will be wrong too.

In the United States, the Department of Transportation lays out the rules for hazmat classification in the Hazardous Materials Regulations, mainly 49 CFR Part 173 and the Hazardous Materials Table in 49 CFR 172.101. Those rules ask a simple but unforgiving question: based on its properties, what hazard class and packing group does this material belong in. Flammable, corrosive, oxidizer, toxic, gas, battery, or something else. From there, the rest of the requirements follow.

For founders and operations leaders, classification can feel like a black box handled by someone else in the supply chain. That is risky. If the box is wrong, your packaging, labels, shipping papers, and carrier choices will all be built on sand.

What classification actually means in practice

Hazardous materials classification is more than slapping a generic hazmat label on a carton. It is a structured process.

You start by identifying the material: what it is, how it is formulated, how it behaves under heat, pressure, and impact, and what it does to people and the environment. Then you compare those properties against criteria in 49 CFR Part 173 and, for many products, the UN Model Regulations. Those criteria decide whether something is, for example, a Class 3 flammable liquid, a Class 8 corrosive, a Class 2 gas, or a Class 9 miscellaneous hazardous material like many lithium batteries.

Once the hazard class is set, you determine the packing group, usually I, II, or III, which reflect high, medium, or low danger within that class. That choice affects how strong your packaging must be, what marks and labels you apply, and what quantity limits apply for different modes of transport.

In other words, classification is the map that tells you which rule set applies. If you use the wrong map, you will not end up where regulators expect you to be.

Everyday products that quietly count as hazmat

One reason classification compliance is so important is that many products do not look dangerous at first glance.

Director of Vendor Operations Kay Hillmann spends her days dealing with exactly that problem. "We are certified in all hazardous materials. We were looking at a matches company, that is a hazardous material. We ship concrete sealant, that is hazardous, a different classification. Paint, your everyday paint you get from a home center, that is hazardous material. Flammables, like gas power generators, that is hazardous material. Perfumes, alcohol."

To shoppers, those are normal products. To regulators and carriers, they are flammable solids, flammable liquids, corrosives, and other hazard classes. A misclassified match product or generator can lead to the wrong packaging, missing labels, and shipping papers that do not match reality.

Kay also reminds brands that classification is not a one and done event. New formulations, new product lines, and new markets can all change how a material must be viewed under the rules. When classification work does not keep up, compliance drifts.

How classification drives packaging and labels

Once classification is set, it drives everything downstream.

Packaging strength and design come from the combination of hazard class and packing group. Performance standards in 49 CFR Part 178 tell you what tests a UN certified box, drum, or jerrican must pass for a given class and packing group. A Packing Group I corrosive needs tougher packaging than a Packing Group III flammable liquid.

Marking and labeling requirements in 49 CFR Part 172 also depend directly on classification. The proper shipping name, UN number, hazard class label, and any subsidiary risk labels all come from the hazard class you assigned. If you misclassify a product, your labels will lie, even if they are printed perfectly.

For lithium batteries, classification determines whether they are treated as small batteries in equipment with limited markings or as fully regulated Class 9 shipments with full hazmat packaging and paperwork. Chief Revenue Officer John Pistone describes what happens when watt hours rise above 300. "If you have a lithium ion battery that is greater than 300 watt hours, it is considered fully regulated. That means there is special packaging that it has to have. Everybody who touches it has to be certified. You have specific requirements in your warehouses, like the type of sprinkler systems. Your insurance is more expensive. Shippers charge you extra to do it."

That fully regulated status starts with classification.

Documentation and carrier rules ride on classification

Hazmat shipping papers and emergency response information also lean heavily on classification decisions.

Under 49 CFR 172.200 through 172.205, shipping papers must list the proper shipping name, hazard class, identification number, and packing group for each hazardous material. The Hazardous Materials Table in 49 CFR 172.101 links each UN number and shipping name to a class and packing group. If classification is wrong, your shipping papers will not match the material, which is exactly what inspectors and carriers look for.

Carriers layer their own rules on top. They decide which hazard classes they will carry, on which services, and in what package sizes. Many ground and air carriers impose special restrictions on certain classes, including Class 3 flammable liquids, Class 2 gases, and lithium batteries as Class 9.

Director of Business Development Matt Bradbury has seen how many competitors avoid this space entirely. "Even our competition, they do not want to touch things that are over 40 or 45 watt hour batteries. Our largest competitor, where I come from, will not touch anything over 40 watt hours." G10 chose a different path by investing in the classification, packaging, and documentation expertise needed to handle these products.

Systems that keep classification from living in a binder

Classification decisions are only useful if they make it into the systems that run your warehouse and shipping.

CTO and COO Bryan Wright explains the role of the warehouse management system. "A bad WMS system will not track inventory 100 percent, as it should. A good WMS tracks inventory through the warehouse at every point that you touch it."

For hazardous materials classification compliance, that tracking must include hazard class, UN number, packing group, and any special handling codes. When an order is picked and packed, the WMS needs to know what packaging to allow, which labels to print, and whether hazmat documentation is required. When inventory is slotted, it needs to respect storage rules tied to specific hazard classes, especially for flammables and corrosives.

Because Bryan and his team built the WMS that G10 runs, they can bake classification into the core data model. New SKUs are onboarded with hazard attributes from day one. Changes to formulations or regulations can be reflected in item master updates, not whispered from supervisor to supervisor.

Training people to use classification correctly

Regulations do not just care that classification is technically correct. They care that the people doing the work understand what it means.

Under 49 CFR 172.700 through 172.704, hazmat employees must be trained on general awareness, function specific duties, safety, and security. For classification, that means people responsible for packaging, marking, labeling, and shipping papers need to know how hazard classes affect their choices. They do not have to become chemists, but they do need to know the difference between a flammable liquid and a corrosive, and what that means for the work in front of them.

G10 built its hazmat program with national experts. Kay explains, "We have been certified by the expert in the country on hazardous materials in all classifications." That training covers not just lithium batteries, but the whole spectrum of hazard classes. When employees understand classification, they are more likely to catch mismatches, like a corrosive label on a pallet that is supposed to be all flammables.

Why classification matters for retailers and omnichannel

Big box retailers and marketplaces care about classification compliance even if they do not always use that language.

Director of Operations and Projects Maureen Milligan has watched brands grow into Walmart, Target, and other large chains. She explains that each retailer has specific requirements for labeling, palletization, and documentation. G10's WMS was built to handle those vendor specific needs. "We have always been able to make these at a very discrete level, meaning if every Walmart has to have the same label, but Target needs a different label, and someone else needs their own labels, we have that ability."

When products are hazardous, classification must line up with those retailer rules and with carrier restrictions. You cannot promise a retailer aggressive delivery windows if the underlying classification would force a slower mode or more complex documentation.

VP of Customer Experience Joel Malmquist talks about omnichannel growth as a planning exercise. "With an up and coming business, I am going to ask you questions. What channels are you trying to get into. How do you see your business growing. How can we help you get there." Classification sits quietly in the middle of those answers. A product that is Class 3 or Class 9 under transport rules may have a very different channel strategy than one that is not regulated at all.

Questions to ask before you scale hazmat

If your product line already includes hazardous materials, or you are considering new products that might cross that line, this is the time to treat classification as a strategic topic.

Ask your suppliers how they classified each product and which sections of 49 CFR or UN guidance they used. Ask for written classification decisions and supporting Safety Data Sheets, not just a checkbox in a catalog. Ask your 3PL how they record hazard class, UN number, and packing group in their systems and how that information flows into packaging, labeling, and documentation.

Ask who owns classification updates when formulations change or new markets are added. A brand that leaves classification scattered across emails and spreadsheets will eventually run into conflicting answers.

Turning classification into a foundation, not a fire drill

Hazardous materials classification compliance will never be the flashiest part of your brand story. But it is one of the most important. It shapes packaging, labels, documentation, storage, carrier selection, and retailer relationships. Get it right early and everything downstream becomes easier. Get it wrong and you inherit a mess of rework, fines, and delays.

Kay sums up G10's approach neatly. "We follow regulations and guidelines to a T because we want to make sure that we are doing it legally, correctly, and safely." Applied to classification, that mindset means each product starts with a solid, documented decision before anyone touches a box or prints a label.

If your next stage of growth includes more complex products or new markets, talk with G10 about how to build hazardous materials classification compliance into your onboarding process so every downstream move starts on solid ground.