A practical, numbers-first playbook to set ANSI/ASQ Z1.4 (ISO 2859-1) AQL plans for Indonesian IQF vegetables. How many cartons to open, which code letter to use, and acceptance/rejection numbers for critical/major/minor defects—with ready-to-copy spec wording.
If you buy or sell IQF vegetables, your AQL plan is where quality wins or unravels. After years setting up inspections for Indonesian packs—from single-SKU Premium Frozen Sweet Corn to mixed loads of Frozen Paprika (Bell Peppers) and Premium Frozen Okra—we’ve learned that clarity beats complexity. This guide lays out exactly how we structure ANSI/ASQ Z1.4 (ISO 2859-1) sampling for 2026 shipments, including real numbers you can copy into your spec.
Start here: set your ANSI/ASQ Z1.4 (ISO 2859-1) plan
We recommend using ANSI/ASQ Z1.4 (equivalent to ISO 2859-1) with General Inspection Level II and single sampling under Normal inspection. It’s the most common baseline among EU and US buyers for IQF vegetables.
How do I pick the right code letter for my IQF shipment?
Two quick choices determine everything else:
- Define the inspection unit. For IQF, it’s usually the primary pack (e.g., 1 kg bag). If you ship bulk 10 kg cartons without inner packs, then the carton is the unit.
- Determine lot size. Use the total number of units in the shipment per SKU and production date.
Then match lot size to the code letter (Level II). Examples we see often:
- 1,200–3,200 units → Code letter K → sample 125 units
- 3,201–10,000 units → Code letter L → sample 200 units
- 10,001–35,000 units → Code letter M → sample 315 units
- 35,001–150,000 units → Code letter N → sample 500 units
What AQL levels do buyers typically use for Indonesian IQF vegetables?
Our baseline unless a buyer specifies otherwise:
- Critical defects: 0.0 AQL. Zero tolerance for foreign matter and safety issues.
- Major defects: 2.5 AQL. Material defects that impact safety, function, or saleability.
- Minor defects: 4.0 AQL. Cosmetic or slight defects that don’t materially affect use.
How many cartons should I sample in a 40ft container at AQL 2.5/4.0?
It depends on the unit you defined:
- If the unit is the inner bag. A typical 40ft with 1,800 cartons of 10 x 1 kg bags is 18,000 units. Code letter M → sample 315 bags. To reach 315, you’ll open at least 32 cartons (10 bags each), randomly spread across the container.
- If the unit is the carton (bulk 10 kg). A 40ft with 1,800 cartons is a lot size of 1,800. Code letter K → sample 125 cartons.
In practice, we always spread selection by front/middle/rear, floor/mid/top, and left/right to avoid cluster bias. That simple habit catches 3 out of 5 issues we’ve seen others miss.
Acceptance numbers you can use today (single sampling, Normal)
Here are working examples from the standard that cover most scenarios:
- Lot 8,000 units (e.g., 1 kg bags of Premium Frozen Sweet Corn)
- Code letter L → sample size 200
- AQL 2.5 major: accept 7, reject 8+
- AQL 4.0 minor: accept 10, reject 11+
- Critical: zero tolerance (any critical defect = reject)
- Lot 18,000 units (e.g., mixed pallet program of Frozen Paprika)
- Code letter M → sample size 315
- AQL 2.5 major: accept 10, reject 11+
- AQL 4.0 minor: accept 14, reject 15+
- Critical: zero tolerance
- Lot 50,000 units (large retail program)
- Code letter N → sample size 500
- AQL 2.5 major: accept 14, reject 15+
- AQL 4.0 minor: accept 21, reject 22+
- Critical: zero tolerance
Pro tip: if you run composite inspections for multiple pallets, keep traceability. Record which cartons fed each sub-sample. If the lot fails, you’ll know which pallets to quarantine first.
What’s the difference between AQL sampling and defect limits?
AQL sampling is your method. It says how many units you check and how many defects you can accept before you reject the lot. Defect limits live in your product specification. They define what counts as a defect and how to classify it. You need both. A clear spec without a sampling plan is toothless, and a sampling plan without defined defects is guesswork.
Which defects count as critical, major, and minor for IQF vegetables?
What matters most is aligning to your market and product. Here’s a practical baseline we use across IQF lines like Premium Frozen Okra, Frozen Mixed Vegetables, and Premium Frozen Potatoes:
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Critical (0.0 AQL, zero tolerance)
- Hard or injurious foreign matter: glass, metal, stones, hard plastic fragments, bone, wood splinters
- Live insects or pests, severe contamination, lubricants/grease
- Undeclared allergens or wrong species
- Severe decomposition/putrefaction
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Major (AQL 2.5)
- Foreign vegetative matter (e.g., husk, pod, stem) above spec
- Excessive clumping not separating under gentle tap or 30-second shake
- Freezer burn or severe dehydration patches
- Size/length outside tolerance for cuts (e.g., cut carrots, okra slices)
- Underweight beyond spec limit (see weight section below)
- Oxidized/discolored pieces beyond limit, off-odors after thaw
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Minor (AQL 4.0)
- Slight size/shape variance within tolerance
- Minor surface blemishes or color variability
- Small broken pieces or chips within limit
- Light frost accumulation that doesn’t affect product after cook
Trend watch for 2026: EU retailers have tightened what counts as “hard plastic.” Opaque and colored fragments are being treated like glass in several programs. We treat them as critical unless your buyer says otherwise.
Net weight and glaze checks under your AQL plan
We separate attribute defects from quantitative checks but keep them inside the same sampling pull to avoid bias.
- Glaze verification. Randomly take 10 units from your AQL sample. Measure gross frozen weight, deglaze fully under running water, re-freeze surface, then measure net product weight. Document method and temperatures.
- Weight acceptance. Align to the market’s average weight rules. For retail EU packs, many buyers apply the Average Quantity System. In our specs, a single unit short by >2% is a Major defect. Systematic underfill or average below nominal is grounds for lot failure regardless of AQL counts.
Normal vs tightened inspection: when should you switch?
Under the standard’s switching rules, you move from Normal to Tightened when two out of five consecutive lots are rejected on original inspection. You return to Normal after five consecutive accepted lots. That’s the textbook approach.
In practice, many retail buyers now require immediate Tightened after a single failure on critical or major defects. We support that for high-risk SKUs or new vendors, especially in programs with strict zero-tolerance foreign matter policies.
Can I combine different SKUs in one lot for AQL sampling?
Short answer: don’t. Sample by SKU, production date, and specification. If you must combine for logistics, only group items that are truly identical in recipe, cut size, processing line, and shift. Otherwise, you’ll dilute the signal and miss SKU-specific issues. We’ve seen mixed-SKU lots pass sample AQL then throw customer complaints within weeks. Not worth it.
A realistic container sampling plan that works
Here’s the field method our team uses for pre-shipment inspection of IQF vegetables in Indonesia:
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Define the unit (bag or carton) and lot size per SKU/date. Select Level II and find the sample size.
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Randomize carton picks across the container: front/middle/rear, bottom/middle/top, left/right. Avoid edge-only bias.
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From each selected carton, pull a fixed number of units to reach your sample size. Keep a running tally.
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Inspect still-frozen for clumps, size, foreign matter, bag integrity, print/labeling. Thaw a subset for color, texture, odor, and cook test if required.
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Record all findings with photos and carton IDs. If you find any critical defect, stop and escalate.
If you’d like us to sanity-check your sampling math or adapt it to your load plan, feel free to Contact us on whatsapp. We’re happy to review a draft in under 24 hours.
Ready-to-copy AQL clause for your IQF purchase spec
Paste this into your PO or technical agreement and tweak the SKU-specific bits:
“Inspection shall follow ANSI/ASQ Z1.4 (ISO 2859-1) General Inspection Level II, Single Sampling, Normal inspection. The inspection unit is the [1 kg retail bag / 10 kg bulk carton]. Lot size is defined as all units of one SKU and production date per container. Sample sizes are determined by the code letter corresponding to the lot size. Acceptance quality limits: Critical 0.0 (zero tolerance), Major 2.5, Minor 4.0. Critical defects include hard/injurious foreign matter, live pests, undeclared allergens, severe contamination. Major and Minor defects are as per the Product Specification. Net and glazed weights are verified on the AQL sample using the agreed method. Any Critical defect results in lot rejection. Tightened inspection will be applied after a failed lot and maintained until five consecutive lots are accepted.”
Two non-obvious wins we’ve learned the hard way
- Define clumps precisely. “Clumps that don’t separate with a 30-second gentle shake at -10 to -15°C” is far more enforceable than “excess clumping.” It reduces debates on the dock.
- Lock the unit first. Half of AQL disputes trace back to someone assuming the unit was a carton while the other side assumed a bag. Write it into the PO header.
If you’re evaluating Indonesian IQF supply for retail or foodservice, you can browse our current lines, specs, and cut options here: View our products.