How to run a simple drop test in your own warehouse

You want to switch from bubble wrap to paper, or take one layer of cushioning out to save money. Your supplier (and yes, sometimes that is us) says the new pack is just as good.

Before you change every order on the packing line, drop a few boxes yourself.

We make cushioning, so we have a stake in which pack wins. That is exactly why I would rather you test it than take our word, or anyone else's.

A warehouse drop test is a fair comparison, not a certificate. Pack the old way and the new way, drop each box in the same order from the same height onto the same hard floor, then open them and judge against rules you wrote down before the first drop. The International Safe Transit Association (ISTA) writes transport test procedures that many labs and shippers use, and I have borrowed their structure here.

The 2020 ISTA guidelines put the case for testing simply: "even a simple lab test used wisely is preferable to trial and error".

A warehouse floor is not a lab. But I am sure a careful test there still beats guessing, and it costs you a few boxes and an afternoon.

What a warehouse test can and cannot tell you

It can tell you:

1. Which of two packs protects better against drops.
2. Where a pack is weak: one corner, the base, the product's handle.
3. Whether you can take material out and still pass.

It cannot tell you:

1. How the pack handles vibration on a long truck ride, or the weight of other parcels stacked on top. The ISTA parcel tests include both.
2. How it handles humid air or low pressure in an aircraft hold.
3. Anything a buyer can treat as certification.

So use the drop test to choose between packs, and then confirm the winner with real shipments.

Which ISTA test is closest to your shipments?

ISTA publishes a free overview of each test on its website. These are the three most useful for online sellers:

3P is good news for Indian sellers. Its overview says ISTA commissioned field research on the Indian parcel system in 2019 and published the test in 2026. So it is built on Indian conditions, not borrowed from another market.

All three overviews say the drop height varies with the packed weight. The exact heights are in the full procedures, sold in the ISTA online store (members get them free). Because ISTA sells them, I will not copy its tables here. If you test often, buy the procedure that matches your route. The ISTA guidelines treat these drop heights as minimums, so never drop lower than the stated height.

Choosing heights for a fair comparison

You do not need the ISTA table to compare two packs fairly. You need both packs dropped from the same, realistic heights. Take them from your own dispatch chain:

1. Measure the heights your parcels actually fall from: the top of your packing table, the floor of the pickup van or your loading dock, and the height at which your loaders actually carry a box of this weight. Watch them for a few minutes and measure it.
2. Mark those heights on a wall or pillar with tape, in centimetres.
3. Start both packs at the lowest height and run the full sequence below.
4. If both survive, pack fresh boxes and repeat at the next height. Stop when one pack fails.

I like this step method because it gives you a clear winner even without the official table.

The pack that survives the higher step is the stronger one against drops. If both survive your highest real height, you have learned that drops are not where they differ, and the cheaper pack may be good enough. Check it with trial shipments before you switch.

Mark the faces, edges and corners

ISTA procedures use a system for naming each face, edge and corner, so every lab drops the box the same way. The 2020 guidelines also say that when a package does not fit the usual scheme, you should make a logical system of your own and record it. For a warehouse test, a simple one works:

1. Stand the box the way it will travel, with the address label on top.
2. Write 1 on the top, 2 on the right side, 3 on the bottom, 4 on the left side, 5 on the front end and 6 on the back end.
3. Name an edge by its two faces (edge 3-5 is where the bottom meets the front) and a corner by its three faces (corner 3-4-5).

Write the scheme on your record sheet, so the next person drops the same corner.

The drop sequence I suggest

I suggest ten drops per box. This is my own short sequence for comparing packs, not an ISTA procedure, but it follows the same idea of hitting faces, edges and a corner:

1. The bottom corner you think is weakest. Usually that is the corner nearest the heaviest or most fragile part of the product.
2. The first edge that meets at that corner.
3. The second edge that meets at that corner.
4. The third edge that meets at that corner.
5. The bottom face (face 3).
6. The top face (face 1).
7. The right side (face 2).
8. The left side (face 4).
9. The front end (face 5).
10. The back end (face 6).

Open nothing between drops. Look at the outside of the box after each one and note anything new.

Setting up the drop

1. The floor. Use bare, flat concrete, the hardest floor you have. Not tiles, which crack, and not a rubber mat, which softens the hit and flatters your pack. Labs use a free-fall drop tester built to ASTM D5276 or ISO 2248, which ISTA names in its overviews.
2. The height. Measure from the floor to the lowest point of the box, the face, edge or corner that will hit first.
3. The angle. The ISTA guidelines ask for flat drops to land within 2 degrees of flat, and edge and corner drops within 5 degrees. For a corner drop, the corner should sit straight below the centre of the box. By hand you will not hit that every time, so film each drop on a phone in slow motion and note any drop that landed badly.
4. The release. Two people work best: one holds and releases, one checks the angle from the side and films. Open both hands at the same moment. Do not push, throw or spin the box.
5. Safety. Wear safety shoes, keep feet out of the landing area, and open glass products with gloves on. If a box is too heavy to hold steady at the test height, do not hand-drop it. That is a job for a lab.

How many boxes?

ISTA asks for a minimum of one sample for 1A and 3A. It also recommends repeating the test five or more times with new samples, and its 3A and 3P overviews recommend two or more samples for fragile products and liquids.

For a warehouse comparison, I would use at least three boxes of each pack. Have them packed by your normal packer, on a normal day, from normal stock. A box packed carefully by the supervisor for the test tells you how the supervisor packs.

If your parcels travel through the monsoon, leave one extra set of packed boxes in the dampest corner of your warehouse for a few days before you drop them. It is not the ISTA conditioning, but it is closer to July than an air-conditioned office.

Decide pass or fail before the first drop

Every ISTA overview asks the shipper to decide, before testing, what counts as damage, how much damage is acceptable, how the product will be checked, and what condition the package may be in at the end. ISTA does not decide that for you. Write it down. For example:

1. Product: no breakage, cracks, chips, leaks or dents, and it still works. Switch it on, open it, pour it.
2. Retail box, if the customer sees it: scuffs are fine, a crushed corner is not.
3. Outer box: dents are fine, but it must stay closed, with no hole and nothing escaping.
4. Cushioning: no sign that the product pushed through to the box wall.

Then apply the rule ISTA uses: if any sample fails any test, the whole test is failed. Do not average three boxes into a pass.

What to record

Photograph the product and the open pack before testing. After the last drop, open the box slowly and photograph each layer as you remove it. The way the cushioning moved tells you as much as the product does.

I would keep the videos and the sheet together in one folder per test. Months later, when you change a supplier or a box size, they show you exactly what the old pack could take.

Reading the results

If the new pack fails and the old one passes, you have saved yourself a bad month of returns.

If both pass, the ISTA guidelines describe a useful next step called "reduce to damage": take some packaging out, test again, and repeat until you find the point where the pack starts to fail. Then go back to the last version that passed. That is how you find a real saving instead of a guess.

If both fail, compare where they failed. It points to the fix: a weak corner, a cushion that bottomed out, a product that moved. Our guide to why products break in transit helps you read the marks, and choosing cushioning by product weight and fragility helps you pick the next material to try.

Then confirm the winner on the road. The same guidelines say trial shipments can be used alongside lab testing. Send a batch of real orders in the new pack and watch your damage rate for those orders.

When to pay a lab

A warehouse test is enough for many decisions. I would pay for a lab in these cases:

1. A buyer, importer or marketplace asks for an ISTA test report or certification. The ISTA guidelines are clear that certification comes from ISTA, not from the lab, and the lab must be an ISTA Certified Lab.
2. The product is expensive or very fragile, where one bad batch costs more than the test.
3. The boxes are too heavy to drop safely by hand.
4. You need vibration, stacking, humidity or leak testing, which your warehouse cannot do.

ISTA lists its certified labs on its Find a Lab page.

I will not quote a drop result from someone else's product as proof for yours. A result belongs to one product, in one pack, on one route. If you run this test and the results confuse you, send us the record sheet and a few of the videos. We will go through them with you.