DOT and IATA rules for US specimen couriers shipping Category A and B

What to take away

Medical courier specimens fall into two legal classes: Category A infectious substances, which are UN 2814 or UN 2900, and Category B biological substances, which are UN 3373.
Category A requires triple packaging that passes a drop and pressure test, a shipper's declaration and often a carrier approval. Category B runs on UN 3373 packaging built to IATA PI 650.
Every person who classifies, packs, marks, labels or offers these shipments needs hazmat training under 49 CFR 172 Subpart H, with recurrent training every three years.
Airlines accept these shipments only from trained tenders who present correct marks, labels and paperwork. Ground carriers apply the same 49 CFR rules.
PHMSA fines for misclassification reach into the tens of thousands of dollars per violation, and each package can be a separate violation.
Keep the classification record, training certificates, air waybill, shipper's declaration and delivery records for every shipment.

How 49 CFR and the IATA Dangerous Goods Regulations split Category A from Category B

In the United States, the Hazardous Materials Regulations sit in Title 49 of the Code of Federal Regulations, usually shortened to 49 CFR. The Pipeline and Hazardous Materials Safety Administration writes and enforces them.

PHMSA regulates Category A and B infectious substance shipping in the US, and its Office of Hazardous Materials Safety | PHMSA runs the standards.

The IATA Dangerous Goods Regulations are a separate document published by the airline industry. They restate the ICAO technical instructions in a format airlines and freight forwarders use at the counter. PHMSA harmonizes US hazmat rules with IATA and ICAO standards, which is why both apply to a shipment that moves by air.

So a domestic air shipment of specimens answers to two rulebooks at once. 49 CFR governs the legal baseline. IATA governs what the airline will actually accept at the cargo window.

The split between the two categories starts with a judgment about the specimen itself. Category A is an infectious substance capable of causing permanent disability, life threatening illness or death in humans or animals when exposure occurs. Category B is an infectious substance that does not meet that threshold.

That judgment is made by the shipper, not the courier, and it belongs on the paperwork. A laboratory that calls a culture Category A creates a Category A shipment. If the courier treats it as Category B, the courier inherits the exposure.

The four UN numbers a specimen courier will see

UN number	Proper shipping name	Category	Typical specimen
UN 2814	Infectious substance, affecting humans	Category A	Active viral culture, high risk clinical sample
UN 2900	Infectious substance, affecting animals	Category A	Veterinary isolate, animal tissue
UN 3373	Biological substance, Category B	Category B	Routine blood, urine, swab, tissue for diagnosis
UN 3291	Clinical waste, unspecified	Waste	Discarded sharps and used dressings

UN 3291 matters because couriers who also haul regulated medical waste need to keep it off the specimen manifest. Waste is not a diagnostic specimen and follows different packaging.

What makes a specimen Category A

A culture of a pathogen on the Category A list is Category A. So is a patient sample that a clinician or lab believes contains one. The list includes Ebola, Marburg, Lassa, Nipah, Hendra, variola and several others.

A sample taken for routine diagnosis from a patient who is not suspected of carrying a listed agent is Category B. That covers the overwhelming majority of what a US medical courier moves between clinics, hospitals and reference labs.

HIV, hepatitis B and hepatitis C blood samples drawn for monitoring are Category B. They are infectious, but the regulations do not place them in Category A.

Why the classification drives everything else

Classification sets the packaging, the marks, the labels, the paperwork and the training. It also sets the price, because Category A packaging costs far more than a UN 3373 mailer.

It also sets liability. If a shipment is misclassified downward, the courier and the shipper both face enforcement. If it is misclassified upward, the customer pays for packaging they did not need.

A new operator should build classification into intake rather than guess at the dock. The steps that stand between a medical courier business and opening day are mostly classification and paperwork decisions, and they are covered in this compliance checklist for new owners.

Category A packaging: UN 2814, UN 2900 and the triple-packaging requirement

Category A packaging is the strictest tier in specimen transport. The package must be a UN specification package, meaning a design tested to a standard and marked with the UN symbol and the packaging code.

The code ends in the letters that describe the package type and the performance level. A fiberboard box tested for infectious substances will carry a marking such as 4G/Class 6.2/25/USA, where the 6.2 refers to the division.

Inside that outer box sit three functional layers. The regulations call this triple packaging, and each layer does a job.

The primary receptacle holds the specimen. It must be leakproof and, for liquids, must not exceed the volume limit for the package design.
The secondary packaging holds the primary receptacle with enough absorbent material to take the entire liquid contents if the primary fails.
The outer packaging protects everything, carries the marks and labels, and must pass the drop, puncture and stack tests in the specification.

For liquids in Category A, the primary receptacle limit is generally one litre, and the outer package limit is four litres. For solids, the outer package limit is generally four kilograms. Those limits come from the packing instruction, not from carrier preference.

The pressure test that catches new shippers

Category A liquids must survive an internal pressure differential of 95 kilopascals without leaking. That is roughly the difference between ground level and a cargo hold at altitude.

The test is done on the package design, not on each shipment, so the shipper buys packaging certified to the standard. A generic cooler with a biohazard sticker does not qualify, no matter how well it is taped.

Some Category A shipments need prior approval from the carrier or from an authority. PHMSA approvals and permits create exceptions to standard packaging rules, and a courier who wants to move something outside the ordinary design should check whether an approval applies before quoting the job.

Marking and labelling a Category A package

A Category A package carries the UN number and proper shipping name, the shipper and consignee, the net quantity, and the name and phone number of a responsible person. It carries the Class 6.2 infectious substance label and an orientation label for liquids.

If the shipment moves by air, it also carries a shipper's declaration for dangerous goods, signed by a trained person. The declaration is a legal document. A courier who signs one without training is exposing the company.

The outer package also needs the UN specification marking, which is printed or applied by the packaging maker. Do not cover it with tape or a routing label.

Temperature control is separate from hazard compliance

A validated cold chain is a specimen integrity requirement, not a hazmat requirement. Dry ice, if used, adds its own classification as UN 1845 and its own marking and ventilation rules.

Gel packs, refrigerated boxes and insulated shippers all add weight and cost. Build them into the packaging design so the outer box still passes its tests with the coolant inside.

Category B packaging under UN 3373 and the PI 650 standard

Category B is the workhorse of US specimen transport. Routine blood tubes, urine cups, swabs and tissue blocks move as UN 3373 Biological substance, Category B, and the packaging standard is IATA packing instruction 650.

The IATA PI 650 specimen standard is a performance based system. It does not require a UN specification outer box. It requires a three part design that meets drop and pressure tests as assembled, and it requires the shipper to be able to show the tests were done.

That is why a UN 3373 mailer can be a lightweight fiberboard box with a plastic secondary bag and absorbent sheet. It is tested as a system, not as a box.

The three layers under PI 650

A leakproof primary receptacle, such as a screw cap tube or a sealed specimen container.
A leakproof secondary packaging, such as a sealed plastic bag, with absorbent material between the primary and the secondary.
A rigid outer packaging with at least one surface of 100 millimetres by 100 millimetres, strong enough to survive a 1.2 metre drop.

Liquid volumes are capped at one litre per primary receptacle and four litres per outer package. The absorbent must handle the full liquid volume of all primaries.

Multiple primary receptacles can share a secondary package if they are wrapped or separated so they cannot break each other. Fragile items need individual wrapping.

Marks and labels for UN 3373

The outer package carries the UN 3373 diamond mark, the words Biological substance, Category B, the shipper's name, address and phone number, and the consignee's details. It carries a responsible person's name and phone number.

It does not carry the Class 6.2 label. That is the most common visual difference between a Category A and a Category B box, and it is the first thing an inspector or an airline counter agent looks for.

By air, a UN 3373 shipment does not need a shipper's declaration in most cases, but the air waybill must state Biological substance, Category B, and the number of packages. Some carriers still ask for a declaration, so confirm before tendering.

Refrigerants and the 3373 mailer

If dry ice is used with a UN 3373 package, the dry ice rules apply on top of PI 650. That means the UN 1845 marking, the net weight, and ventilation instructions.

Wet ice is not permitted in the same way. If a shipment needs wet ice, it is usually moving under a different packing instruction and should be checked before it leaves the dock.

A Category B biological substance courier should keep a small stock of tested mailers in several sizes. Mixing a tested outer box with an untested secondary bag breaks the system and voids the assumption that the design was tested.

Training and certification a US specimen courier must hold before tendering

Hazmat training is the requirement most often skipped by small courier companies. 49 CFR 172 Subpart H requires training for every person who affects the safety of a hazmat shipment.

That includes the person who classifies the specimen, the person who packs it, the person who marks and labels it, the person who fills out the paperwork, and the driver who offers it to a carrier. A dispatcher who decides how a shipment is routed can also fall inside the rule.

Training must cover general awareness, function specific duties, safety, and security awareness. It must be documented, and it must be repeated at least every three years.

A certificate of training is not issued by the government. The employer certifies that the employee is trained, and the employer keeps the record. PHMSA publishes hazmat training resources couriers must complete before tendering specimens, and those materials are a reasonable starting point for a small operator.

What a training file should contain

The file should hold the employee's name, the training date, the topics covered, the trainer's name and the test results if any. It should be kept for as long as the employee works in the function plus the retention period in the rules.

A simple approach is one folder per employee, with a cover sheet listing the four required training elements and the date each was completed. Inspectors ask for this during an audit, and carriers ask for it during onboarding.

Building the file is part of the wider set of licences, permits and inspections a medical courier business needs, because hazmat training records are one of the documents a state or federal reviewer will request.

Driver level training and the vehicle

A driver who handles a Category A package needs function specific training on that package, including what to do if it leaks. A driver who only moves sealed UN 3373 mailers still needs general awareness and security awareness training.

The vehicle itself is not a hazmat package, but the load must be secured so packages cannot fall or crush. A spill kit, gloves, eye protection and absorbent material belong in every vehicle that carries specimens.

Training records should be paired with a written procedure for leaks, exposure and notification. The medical courier compliance checklist is a practical way to sequence the classroom work, the ride along and the sign off.

Recurrent training and new hires

Recurrent training every three years is the floor, not the ceiling. A new hire who has never handled hazmat needs training before the first shipment, not after.

If the company changes what it carries, such as adding Category A work or dry ice, the affected employees need function specific training on the change before the first shipment moves.

Airline and ground acceptance rules for medical courier specimens

Airlines accept dangerous goods only from shippers and forwarders who meet their conditions. Those conditions are usually stricter than the regulations, and they change without much notice.

Most US passenger airlines do not carry Category A infectious substances as cargo at all. Category A usually moves on cargo aircraft, through a known shipper program, or not at all.

Category B moves more freely. Many carriers accept UN 3373 packages as cargo or as checked baggage under specific conditions, and some accept them only through an approved account.

Before quoting an air move, confirm three things with the carrier: whether the commodity is accepted, what packaging they require, and what paperwork they want at the counter. Get it in writing.

The known shipper and security layer

Air cargo security rules require that a shipment be tendered by a known shipper or screened. A courier company that is not a known shipper may need to route through a freight forwarder that is.

That adds a day and a layer of handling. For time critical specimens, it can make ground the faster option even over a long distance.

Ground acceptance under 49 CFR

Ground transport of specimens is governed by 49 CFR, and there is no counter agent to catch a mistake. The driver is the last check.

A ground carrier moving Category A needs the same packaging, marks and labels as an air shipment, minus the air specific paperwork. Placarding generally does not apply to these shipments at the quantities a courier carries, but the driver should know the threshold.

State lines do not change the rules, because 49 CFR applies nationwide. What changes across states is the licensing and vehicle inspection regime, not the hazmat classification.

Working with hospital and lab customers

Hospitals, reference labs and clinics often have their own shipping procedures built around CAP accreditation and CLIA requirements. Those procedures can be stricter than the federal floor.

A courier who follows the customer's procedure and the federal rule at the same time is safest. When the two conflict, the stricter one usually wins in practice, because the customer controls the account and the inspector controls the citation.

The daily routine of pickup, chain of custody and handoff should be written down. A SOP checklist for daily operations keeps drivers from improvising at the dock.

Fines, penalties and misclassification exposure under PHMSA enforcement

PHMSA fines for misclassification are the reason this topic matters to a small courier. Civil penalties for a knowing violation of the hazmat rules run into the tens of thousands of dollars per violation, and the maximum rises with inflation adjustments.

Each improperly prepared package can be counted as a separate violation. A route with twenty packages can turn a single mistake into a very large number.

Penalties can also apply to the person who signs the shipper's declaration, and to the company that offered the shipment. Training records and classification records are the main defense.

The compliance hub where 49 CFR hazmat shipping rules and penalties are located is the place to check current figures, because the amounts are adjusted periodically.

The common misclassification patterns

Calling a Category A culture a Category B sample because the customer said so on the phone.
Shipping a Category A package in a UN 3373 mailer to save money.
Using a generic cooler with a biohazard label instead of a tested outer package.
Omitting the responsible person's phone number.
Letting an untrained driver sign the shipper's declaration.

Each of these is a paperwork failure on the surface and a safety failure underneath. Inspectors find them by comparing the package to the paperwork, not by opening the box.

What an inspection looks like

PHMSA inspects shippers, carriers and freight forwarders. An inspection may start with a records request: training files, classification records, shipping papers and delivery records.

It may also involve watching a shipment being prepared. A driver who cannot explain the difference between UN 2814 and UN 3373 is a finding waiting to be written.

Penalties can be reduced by prompt corrective action and documented training. They are rarely reduced by explaining that the customer packed the box.

Insurance and contract exposure

A general liability policy may exclude hazmat related claims, or may cover them only if the operation is disclosed. A courier moving Category A should tell the broker what the business actually does.

Customer contracts often push regulatory responsibility onto the courier. Read the indemnity clause before signing, and price the work to cover the packaging and training it requires.

Documentation to keep for every Category A and B shipment

Records are what turn a defensible operation into a provable one. Keep a file per shipment, and keep it in a form you can produce within a day.

Classification record showing who decided Category A or Category B, and on what basis
Packaging specification sheet or test report for the outer packaging used
Completed shipper's declaration for Category A air shipments
Air waybill or ground manifest showing the UN number and proper shipping name
Training certificate for every person who packed, signed or drove the shipment
Temperature log or coolant record for cold chain shipments
Delivery confirmation with time, place and receiving person's name

How long to keep the records

Shipping papers and training records have retention periods set in 49 CFR. As a practical matter, keep shipment records for at least two years and training records for the length of employment plus three years.

Digital files are fine if they are readable and retrievable. A scanned shipper's declaration in a shared drive is better than a paper copy in a van.

Building the habit into dispatch

The easiest way to keep records is to make them part of the trip, not a task for the end of the week. A photo of the completed paperwork at pickup takes ten seconds.

A dispatch system that will not close a job without a delivery confirmation enforces the habit without a supervisor. That is the same logic behind the equipment checklist for new owners: standardize the physical kit so the paperwork has something to match.

Common questions

Can a courier ship Category A specimens on a passenger airline? Usually no. Most US passenger carriers refuse Category A infectious substances as cargo, so these shipments move on cargo aircraft or by ground. Confirm with the carrier before quoting.

Does a UN 3373 package need a shipper's declaration? In most air shipments, no declaration is required, but the air waybill must name the substance and package count. Some carriers ask for one anyway, so check their tariff.

How often must hazmat training be repeated? At least every three years under 49 CFR 172 Subpart H. New hires need training before their first shipment, and any change in job function triggers retraining.

Who decides whether a specimen is Category A or Category B? The shipper, usually the laboratory or the clinician who ordered the test. The courier should not reclassify a shipment to reduce packaging cost.

Do state lines change the rules for medical courier specimens? No. 49 CFR applies nationwide, and IATA governs air acceptance everywhere. State rules affect licensing and vehicle inspection, not hazmat classification.

What happens if a package leaks in transit? The driver isolates it, uses the spill kit, and notifies the shipper and the carrier. The incident should be documented and reported as the regulations and the customer contract require.