The 18-point grading standard
Published in full, because a grade you cannot audit is just a letter somebody typed. Eighteen checks, four bands, three outcomes.
- Sheet
- 47
- Revision
- 2026-10
- Scale
- 1:1
- Drawn at
- Peoria IL
Every check, in the order a grader runs them
UN marking legibility
Full code readable and undamaged
Fails to non-regulated service only
Bottle clarity
Light transmission, no haze
Fails to rebottle
Stress whitening
Crazing at corners and sump
Fails to rebottle
Odour after rinse
Neutral
Fails to hot caustic or regrind
Residue staining
Surface versus absorbed
Grade B or C
Valve function
Full cycle, no weep
Valve replacement
Gasket condition
Pliable, no compression set
Gasket kit
Cap and tamper ring
Present, correct thread
Parts fit
Cage weld integrity
No cracked or popped welds
Cage repair
Cage geometry
Square within tolerance
Jig straightening
Rust extent
Surface versus perforating
Cage swap
Pallet soundness
No broken deck or runners
Re-deck
Sump deformation
Flat seat, no bulge
Fails to rebottle
Previous repairs
Workmanship and documentation
Case by case
Label residue
Removable adhesive
De-label cycle
Internal debris
Nothing loose inside
Wash
Leak test
Holds under head pressure
Fails to rebottle or recycle
Stack test (1 in 20)
No creep under rated load
Downgrade
Checks 01 through 16 are visual and functional, run on every container. Check 17 is run on every container that will be re-released for product service. Check 18 is a destructive-risk sample test run on one container in twenty from each intake lot.
Four letters, defined so you can argue with them
| Band | Bottle | History | Markings | Released for |
|---|---|---|---|---|
| A — food | Clear, no stain, neutral odour | Food or food-adjacent, documented | Full UN code legible | Food, beverage, potable-adjacent |
| A — industrial | Light scuffing, no crazing | Non-hazardous, documented | Full UN code legible | Chemical, ag, regulated transport |
| B | Stained, structurally sound | Non-hazardous, rinsed | Usually legible | Ag, water, glycol, general industrial |
| C | Heavy stain, watertight | Known, rinsed | May be partly illegible | Non-potable storage, upcycle builds |
| Cage only | n/a — bottle recycled | n/a | n/a | Structure, storage, racking |
The whole warranty, in one sentence
If a container arrives below the grade we sold, we replace it or refund it — no inspection report required from you, no restocking fee, no argument.
There is no national grading authority — and that is the problem
No standards body grades used IBCs. Every seller invents their own letters, which is why 'Grade A' means three different things across three websites. The only defence a buyer has is to read the definition behind the letter and ask for the evidence: last-contents declaration, wash cycle, certificate, UN photo.
- Ask what the last contents were, by product name rather than category.
- Ask which wash cycle was used, at what temperature, and whether there is a certificate.
- Ask for a photo of the UN marking on the actual containers being sold.
- Ask whether the bottle was replaced, and when.
- Ask what happens if the load arrives a grade below what was sold.
Four levels, written because 'stained' caused the most disputes
Staining was the single biggest source of grading disagreement in our own dispute log, because the word covers everything from a faint tint to an opaque bottle. So we defined it.
| Level | Description | Light transmission | Grade impact | Typical cause |
|---|---|---|---|---|
| S0 — none | Natural translucent bottle, level visible | Full | Grade A eligible | Water, brine, clear chemistry |
| S1 — tint | Faint colour, level still readable | Mostly | Grade A industrial | Light glycol, surfactant |
| S2 — stained | Obvious colour, level readable against a light | Partial | Grade B | Nutrient, glycol, soap |
| S3 — opaque | Level not readable, surface discoloured | Little | Grade B or C | Dark glycol, oil, syrup |
| S4 — ingrained | Residue bonded to the wall, texture changed | None | Grade C or rebottle | Latex, resin, long dwell |
Staining tells you almost nothing about how long a container will last — crazing, sump deformation and cage geometry decide that. What staining decides is whether you can read the level and whether the container can carry a documented food-grade claim, which is why it drives price without driving service life.
How to grade a container yourself in five minutes
Smell the top fitting
Crack the cap and smell at the opening. Solvent, petroleum or chemical odour on a container sold for product duty ends the inspection.
Hold a light behind the bottle
You are looking for crazing at the corners and around the sump — fine networks of surface cracks. The best single predictor of remaining life.
Open the valve and look at the seat
An even witness line is normal service. A broken or pitted line means grit, which means a seal kit at minimum.
Set it on flat ground, check both diagonals
More than three-eighths of an inch of difference across the base and the cage needs straightening before it will stack.
Photograph the UN plate
If you cannot read it, the container cannot carry regulated goods — and that is worth 30 to 60 percent of its value.
| What you find | What it means | What it should cost you |
|---|---|---|
| Crazing at corners and sump | Short remaining life | Grade C money at most |
| Weeping valve | A $6 seal kit | Should not change the grade |
| Cage out of square | Will not stack safely | Grade B at best, repair needed |
| Unreadable UN plate | Out of regulated service permanently | 30–60% discount |
| No contents declaration | Cannot be resold for product duty | Grade B ceiling regardless of looks |
| Bulged sump | Already yielded under load | Rebottle candidate only |
Why does your Grade B cost more than somebody else's Grade A?
Because the letters are not comparable — there is no grading authority in this industry. Compare the definitions and ask for the documentation behind them. Our Grade B has a contents declaration, a wash record and a photographed UN plate; plenty of Grade A listings have none of those.
Can a container be upgraded?
Its condition can be improved — washing, a new valve, cage straightening. Its history cannot. An undocumented container stays capped at Grade B no matter what we do to it, and a solvent-exposed bottle never returns to product service.
Do you grade containers you do not buy?
Yes. Photo grading within 24 hours, or a grader on site at about 60 containers an hour. Free when we buy the load, quoted otherwise.
What if I disagree with a grade?
Tell us within 14 days with a photograph. We replace it or refund it without requiring an inspection report. Across 2024 the customer turned out to be right in 41% of disputes and every one of those was settled.