Shipping hazardous materials: best practices

Shipping hazardous materials safely comes down to getting a short chain of decisions right: what the material is, which rules apply to the mode of transport, which packaging is authorized, how the package is marked and documented, and whether the people doing the work are trained. In the United States those decisions are governed by the Hazardous Materials Regulations (HMR) in 49 CFR parts 171 to 180. Air shipments also follow the IATA Dangerous Goods Regulations (DGR), and ocean shipments follow the IMDG Code.

This guide explains how to ship hazardous materials step by step and sets out dangerous goods handling best practices for storage, training and compliance checks. It is written for labs, biotech and pharma teams, distributors and logistics staff who prepare hazardous goods shipping as part of their daily work rather than as a one-off task.

What counts as a hazardous material in transport

A hazardous material, called dangerous goods in international rules, is a substance or article that can pose a risk to health, safety or property during transport. Common examples in healthcare and life sciences include flammable solvents, corrosive reagents, infectious substances, dry ice, lithium batteries in devices and compressed gases.

Transport rules sort these materials into nine hazard classes, from explosives in Class 1 to miscellaneous dangerous goods in Class 9. Mercury's glossary entry on the nine classes of hazardous materials explains each class. Several materials have their own detailed guides on the Mercury blog, including corrosive liquids under UN1760, lithium ion batteries and dry ice.

Which rules apply to hazardous materials shipping

Hazardous materials shipping is regulated by mode and by route. A single shipment can fall under more than one set of rules, for example a road leg in the US followed by an international flight.

The HMR applicability section, 49 CFR 171.1, lists pre-transportation functions that bring a person under the rules, such as determining the hazard class, selecting packaging, filling a package, securing closures and marking the package. If your staff do any of these, your organization is a hazmat employer even if a carrier moves the freight. For air, IATA describes its Dangerous Goods Regulations as the standard recognized by airlines and places responsibility for correct classification on the shipper. The IMO page on the IMDG Code notes that the Code is amended on a two-year cycle, so confirm you are working from the edition in force on the shipping date for air and sea alike.

How do you ship hazardous materials?

You ship hazardous materials by classifying the material, selecting authorized packaging, marking and labeling the package, completing and signing the shipping paper, and handing it to a carrier that accepts that class of dangerous goods. The shipper owns most of these steps. Under 49 CFR 173.22, the person offering the material must class and describe it and determine that the packaging is authorized and properly manufactured and marked.

1. Classify the material. Identify the hazard class, UN number, proper shipping name and packing group from the Hazardous Materials Table in 49 CFR 172.101, or the IATA or IMDG lists for international moves. Start from the safety data sheet, but verify it, since OSHA does not enforce the transport section of an SDS.

2. Check quantity limits and exceptions. Limited quantity, excepted quantity and special provisions can change packaging and labeling needs. Quantity limits differ by mode, so check them for the mode you will use and, for air, the aircraft type.

3. Select UN specification packaging. Use packaging authorized for that entry and packing group, and assemble it exactly as the packaging manufacturer instructs.

4. Mark and label the package. Apply the proper shipping name, UN number, hazard labels and any orientation or handling marks required for the mode.

5. Prepare the shipping paper. Enter the shipping description, quantity, emergency response telephone number and the signed shipper's certification.

6. Confirm carrier acceptance. Book with a carrier and service that accept the class and quantity, and check any carrier-specific variations or account approvals before pickup.

7. Keep records. Retain the shipping paper and packaging documentation for the required period.

Mercury's glossary walk-through on preparing a hazardous shipment gives a short checklist version of the same flow.

Packaging: what a UN specification mark tells you

UN specification packaging carries a code that shows how it was tested. Under 49 CFR 178.503, the mark includes the UN symbol, a packaging identification code for the type and material, a letter showing the performance level, the tested specific gravity or maximum gross mass, and the last two digits of the year of manufacture, among other elements. The performance letters are X for packagings that passed Packing Group I, II and III tests, Y for Packing Group II and III, and Z for Packing Group III only.

Read the mark before you fill the box. A Z-rated packaging cannot carry a Packing Group II material, and a box tested for solids cannot be used for a liquid without suitable inner packagings. The same section of 49 CFR 173.22 requires shippers of non-bulk UN packaging to keep a copy of the manufacturer's notification, including closure instructions, and to make it available for at least 90 days after the package is offered to the first carrier. For specialist or oversized items, Mercury's packaging and crating service can help with the physical build.

Documents: shipping paper, certification and emergency contact

The shipping paper, or the Shipper's Declaration for Dangerous Goods on air shipments, is where most rejections happen. Under 49 CFR 172.204, each person who offers a hazardous material must sign a certification that the material is properly classified, described, packaged, marked and labeled, and in proper condition for transport.

The paper also needs an emergency response telephone number. 49 CFR 172.604 requires that the number is monitored at all times while the material is in transportation, including storage incidental to transportation, and that it reaches someone knowledgeable about the material or with immediate access to such a person. An answering service or a number that needs a call back does not meet the rule. Keep a copy of each shipping paper for two years after the initial carrier accepts the material, or three years for hazardous waste.

What are the best practices for handling dangerous goods?

The best practices for handling dangerous goods are to work from written procedures, handle each package only as its labels and the SDS allow, keep incompatible materials apart, and stop the shipment whenever something does not match the paperwork. Rules set the minimum, and good dangerous goods handling turns them into routines that people follow on a busy day.

• One owner per shipment. Assign a trained person to sign off classification, packaging and documents, rather than splitting decisions across a team without a final check.

• Standard packing instructions. Write a packing instruction for each recurring material that lists the UN number, packaging, absorbent, closure torque or method, labels and paperwork.

• Two-person check before release. Have a second trained person compare the package, marks and labels against the shipping paper.

• Protect labels and orientation. Keep packages upright where orientation arrows apply, and do not overwrap labels with tape or pallet wrap.

• Treat damage as a stop signal. A leaking, dented or wet package goes to a quarantine area and is not shipped until a trained person assesses it.

• Plan for temperature. Refrigerated and frozen materials often add dry ice, which is itself a dangerous good and needs ventilation and its own marks.

These dangerous goods handling best practices also apply to receiving. Inbound hazmat should be checked on arrival, logged, and moved to the right storage area before anyone opens it.

What training is required to ship hazardous materials?

US hazmat training requirements cover every hazmat employee, meaning anyone who classifies, packs, marks, labels, documents, loads or handles hazardous materials for transport. Under 49 CFR 172.704, training must include four core parts:

• General awareness and familiarization, so the employee can recognize and identify hazardous materials.

• Function-specific training on the rules that apply to the tasks the employee actually performs.

• Safety training on emergency response information, protective measures and accident avoidance, including proper handling of packages.

• Security awareness training, which new hazmat employees must receive within 90 days after employment.

Employers that must have a hazmat security plan also need in-depth security training for the staff it covers. A new employee, or one who changes job functions, may work under the direct supervision of a trained employee for up to 90 days before completing training. Recurrent training is required at least once every three years. Section 172.702 adds that each employee must be tested on the training subjects.

The employer must keep a training record covering the preceding three years for as long as the person works in a hazmat role and for 90 days after. The record lists the employee's name, the most recent completion date, a description or copy of the materials, the trainer's name and address, and certification that the employee was trained and tested.

Air shipments add their own layer. IATA states that recurrent dangerous goods training is required every 24 months to keep certification valid, which is shorter than the three-year DOT cycle. Teams that ship by air should plan around the shorter interval. Mercury's article on how to train employees on import and export procedures covers how to build training into wider trade compliance.

How should hazardous materials be stored before shipping?

Hazardous materials should be stored before shipping in a designated, access-controlled area where incompatible classes are kept apart, packages stay closed and labeled, and current safety data sheets are on hand. Hazardous material storage and shipping are closely linked, because a package damaged or mixed up in storage becomes a transport problem the moment it is picked up.

Practical storage controls include:

• Segregation. The HMR segregation rules in 49 CFR 177.848 apply to storing, loading and transporting packages on highway vehicles. For example, Division 4.2 materials may not be stored or loaded with Class 8 liquids, and cyanides may not be stored with acids where mixing would generate hydrogen cyanide. Use the same logic in your staging area.

• Safety data sheets. OSHA's Hazard Communication standard requires employers to keep an SDS for each hazardous chemical in the workplace, readily accessible to employees during each shift.

• Environment. Keep temperature-sensitive or reactive materials within the storage conditions on the SDS and away from heat sources, and ventilate any area holding dry ice.

• Containment and access. Use spill trays or bunded shelving for liquids, keep spill kits nearby, and limit access to trained staff.

• Staging discipline. Keep packed and labeled shipments in a separate staging zone so they are not reopened, relabeled or mixed with outbound general freight.

Local fire codes and building permits can also limit how much of a flammable or oxidizing material you may hold in one area, so confirm limits with your facility's environmental health and safety team or local fire authority.

What dangerous goods certified storage should mean

Providers sometimes advertise dangerous goods certified storage. There is no single US certificate with that name, so ask what the claim covers. A credible answer names the regulations followed, describes segregation by class, shows current SDS and training records, and explains how the site handles spills, fire protection and access control. If a warehouse cannot show these, treat the label as marketing rather than evidence.

How do you ensure compliance in hazardous materials shipping?

You ensure compliance in hazardous materials shipping by assigning clear responsibility, training and testing every hazmat employee, using written procedures for each recurring material, checking each shipment before release, keeping records, and auditing the process regularly. Chemical shipping compliance is a management system, not a single form, and the regulations make the employer responsible for compliance whether or not training has been completed.

The table below links common errors to the controls that prevent them.

Audit on a fixed schedule and after any incident or rejection. Pull a sample of recent shipping papers, check them against the packages that went out, review training records for every signer, and walk the storage area with the segregation table in hand. Track findings to closure, and update packing instructions when a rule edition, packaging supplier or carrier policy changes.

Hazardous goods delivery with the right partner

Hazardous goods delivery for healthcare and research often combines dangerous goods rules with temperature control, customs and tight timelines. For example, Mercury has supported the import of temperature-sensitive biohazardous research material from Canada into the US, handling classification, clearance documentation and packaging for samples that had no duplicates. Mercury's glossary on shipping hazardous materials and its guide to classifying biological shipments are useful next reads for teams building their own procedures.