Silicone Food Storage Bag OEM Guide — Cure, Compliance, MOQ

The silicone food storage bag is the highest-scrutiny food-contact SKU in the reusable-kitchen category — repeated flex cycles at the closure, direct food contact across a service-temperature range from freezer to boiling, and a regulatory stack (FDA + LFGB + Prop 65 + PFAS) that no consumer roundup surfaces to buyers. Every serious retail program above $12 shelf-price now audits the same seven documents pre-PO. This guide is the engineering reality of manufacturing that product — cure chemistry, closure engineering, MOQ-tier FOB pricing, defect CTQ points, and the sourcing workflow from RFQ to PPAP — written from inside a working Dongguan OEM factory floor for procurement teams at housewares, sink, pet, medical, and baby brands.

A silicone food storage bag is a one-piece platinum-cured LSR (or post-cured peroxide HCR) shell 0.7-1.4 mm thick, Shore A 45-60, molded on 4-8 cavity injection tools with an integrated slider zipper, press-seal channel, or vacuum-port closure. Post-cured 4-6 hours at 180-200°C to clear LFGB §30/§31 organic volatile testing per BfR Recommendation XV. For B2B OEM programs, MOQ 500 pieces per SKU delivers per-batch FDA 21 CFR 177.2600 + LFGB + Prop 65 + PFAS test reports. FOB Yantian for a 500 ml platinum-cure slider-closure bag with 1-color debossed logo runs $3.20-$4.10 at 500 pcs, dropping to $1.75-$2.20 at 10,000 pcs. Total realistic lead from RFQ to US warehouse: 75-110 days including 14-18 day Yantian sailing.

What is a silicone food storage bag, engineered for OEM production?

A silicone food storage bag is a one-piece molded PDMS shell at Shore A 45-60 durometer per ASTM D2240[^astm-d2240], wall thickness 0.7-1.4 mm, cured on a 4-8 cavity injection or compression tool at 160-200°C. Continuous service temperature -40°C to 230°C. The closure system — integrated slider zipper, press-seal channel, or vacuum port — is either co-molded (platinum LSR two-shot) or bonded in a secondary process (peroxide HCR with silicone primer). Closure engineering, not shell chemistry, drives 60% of tooling cost and 100% of retail-tier positioning.

Consumer-facing coverage of silicone food storage bags describes them as “reusable, dishwasher-safe, freezer-to-oven”. The engineering description is a three-part system layered into one 1 mm shell. The shell provides food-contact chemistry (FDA 21 CFR 177.2600¹ compliance, thermal envelope, structural integrity under vacuum). The closure provides the sealing function under repeated flex cycles across 2-5 year service life. The bonding chemistry between shell and closure (or the two-shot LSR interface, on platinum tooling) provides delamination resistance across 2,000+ open-close cycles.

Every meaningful engineering decision on a bag program is a trade-off between those three subsystems. Thicker shell wall = better structural integrity under vacuum, higher per-unit cost. Softer shell durometer = better fold flexibility, worse dimensional stability during freezer cycling. Slider closure = higher retail-tier positioning, higher tooling cost. The rest of this guide walks the trade-offs one by one.

Baseline engineering spec sheet

Parameter	Standard range	Test method
Shell wall thickness	0.7-1.4 mm (typical retail: 0.9-1.2 mm)	Ultrasonic gauge, 8-point sampling
Shell Shore A hardness	45-60 (retail); 55-65 (heavy-duty commercial)	ASTM D22402
Valve Shore A hardness (vacuum-port SKUs)	35-45 (softer than shell for seal engagement)	ASTM D22402
Tensile strength	≥ 6.5 MPa	ASTM D412
Elongation at break	≥ 350%	ASTM D412
Tear resistance	≥ 22 kN/m	ASTM D624
Continuous service temperature	-40°C to 230°C	LFGB thermal cycling per BfR XV3
Freezer service	-40°C for ≥ 90 days without embrittlement	Internal + LFGB extractables
Slider bead height tolerance	±0.05 mm	Optical comparator, 5-point
Press-seal channel interference	0.15-0.25 mm crush	Feeler-gauge sampling
Cure system	Platinum LSR or peroxide HCR	Master-batch lot certificate
Cure temperature at press	160-200°C	Press PLC log
Post-cure cycle	4-6 h @ 180-200°C	Batch oven log
Closure cycle-life target	≥ 2,000 open-close cycles, zero seal degradation	Automated cycle-tester fixture

What certifications does a silicone food storage bag need for retail?

The mandatory stack for serious retail bag programs is FDA 21 CFR 177.2600[^fda-177-2600] (US food contact), LFGB §30/§31 organic volatile testing per BfR Recommendation XV[^bfr-lfgb-xv] (EU food contact), EU Regulation 1935/2004[^ec-1935-2004] framework declaration (EU market entry), California Prop 65 Chapter 6 heavy-metals declaration (US market entry), and per-batch PFAS non-detect testing at ppb detection limits driven by the ECHA restriction proposal[^echa-pfas-proposal]. All five referenced to a specific master-batch lot from the last 6 months.

The bag category raises the certification bar above baking mats because the product sees direct liquid food contact — including acidic, alcoholic, and fatty foods — across a wider temperature range and a longer service life. Retail auditors treat the documentation stack as a gate, not a preference.

The five-layer certification stack

Layer 1 — FDA 21 CFR 177.2600 (US baseline). The primary US food-contact regulation for rubber articles intended for repeated use. Tests aqueous, 8% ethanol, and n-heptane extractables against defined limits. Every US retail SKU needs this on file, tested per master-batch lot at accredited third-party labs (SGS, Intertek, TÜV, Bureau Veritas).

Layer 2 — LFGB §30/§31 (EU / premium US). German Food and Feed Code sections 30 and 31, technically grounded in BfR Recommendation XV³ and framed by EU Regulation 1935/2004⁴. Tests organic volatile extractables under stricter protocols than FDA — the reason mandatory 4-6 hour post-cure exists on every bag batch. Any EU program and any US premium retail demands this alongside FDA.

Layer 3 — EU Regulation 1935/2004 framework declaration. The overarching EU framework regulation⁴ for food-contact materials — a signed declaration of conformity referencing the framework plus underlying LFGB test data. Required for any EU market entry independent of the LFGB report itself.

Layer 4 — California Prop 65 Chapter 6 heavy-metals declaration. California Proposition 65 lists heavy metals (lead, cadmium, mercury, arsenic) with parts-per-million action levels. Any US retail SKU sold in California — which effectively means any US retail SKU — needs a heavy-metals test report and a Prop 65 conformity declaration. Third-party lab tests at ppm detection limits per master-batch lot.

Layer 5 — PFAS non-detect (accelerating requirement). Per-batch PFAS testing at ppb detection limits from an accredited lab. Not a formal certification — a test report on the finished-part material. Driven by the ECHA universal restriction proposal⁵ and downstream retailer spec adoption. Now table-stakes on any EU premium program and increasingly required on US West Coast retail.

Tier-specific additional documents

Retail tier	Layer 1 FDA	Layer 2 LFGB	Layer 3 EU 1935	Layer 4 Prop 65	Layer 5 PFAS	Additional
US mass retail ($8-14 shelf)	Required	Recommended	—	Required	Recommended	—
US premium retail ($14-30 shelf)	Required	Required	—	Required	Required	—
EU retail (all tiers)	Required	Required	Required	—	Required	REACH declaration
Commercial-kitchen adjacent	Required	Required	—	Required	Required	NSF/ANSI 516
Infant / baby-food tier	Required	Required	Required	Required	Required	CPSIA7
Medical / clinical-adjacent	Required	Required	Required	Required	Required	USP <88> extract testing

Full breakdown of the FDA vs LFGB decision framework on our FDA vs LFGB silicone decoder.

Platinum-cured or peroxide-cured silicone — which cure system for bags?

Platinum-cure LSR by default for any retail bag program at $12+ shelf, and mandatory on EU premium, PFAS-free positioning, and infant-tier programs. Peroxide-cure HCR with mandatory 4-6 hour post-cure at 180-200°C is viable for US mass retail at $8-14 shelf. Bags amplify the decision because the closure bead sees 2,000+ repeated flex cycles across service life — under-post-cured peroxide-cure at the bead generates first-heat odor and, in edge cases, LFGB §30/§31 failure that under-post-cured drying mats never trigger.

Both cure systems use the same PDMS polymer. The catalyst that triggers crosslinking is where they diverge — platinum for platinum-cure, organic peroxide for peroxide-cure — and that catalyst choice cascades into byproduct chemistry, first-heat odor risk, per-unit cost, and closure-tooling geometry.

For bag programs specifically, cure choice has two extra layers that don’t apply to flat sheet products. First, the closure geometry: platinum LSR supports two-shot co-molded slider zippers where the rail and shell cure together in one press cycle. Peroxide HCR requires a secondary bonding step — the closure profile is molded separately, then bonded to the shell with a silicone primer under a second press cycle. This adds tooling cost, cycle time, and a delamination-mode defect that platinum LSR does not have. Second, the closure bead sees repeated mechanical flex at temperatures from -40°C freezer to 230°C oven — any residual peroxide decomposition byproduct at the bead concentrates in the highest-stress zone and out-gasses first.

Cost delta at bag MOQ tiers

Cure system	500 pcs (500 ml slider)	1,000 pcs	5,000 pcs	10,000 pcs
Peroxide-cured HCR (post-cured, PFAS-free process aid verified)	$2.80-$3.60	$2.30-$2.90	$1.75-$2.25	$1.55-$1.95
Platinum-cured LSR (co-molded closure)	$3.20-$4.10	$2.60-$3.30	$2.00-$2.55	$1.75-$2.20
Delta	+12-15%	+12-14%	+12-15%	+12-15%

Numbers are FOB Yantian, Q3 2026 benchmarks, 500 ml capacity with integrated slider closure and 1-color debossed logo, PDMS at Shore A 50-58, 0.9-1.2 mm wall thickness. Custom Pantone-matched master-batch adds $0.10-$0.18 per unit. Frosted or textured shell finish adds $0.06-$0.12. Retail-ready color header card packaging adds $0.22-$0.45 per unit fully assembled.

Full engineering decision framework for the cure question on our platinum-vs-peroxide-cured silicone decision guide.

Closure engineering — slider, press-seal, or vacuum port

Three engineered closure systems drive 60% of bag program tooling cost and 100% of retail-tier positioning. Integrated slider zipper: co-molded silicone rail with tongue-and-groove profile, captive slider, tooling $12,000-$18,000. Press-seal channel: interference-fit crush at 0.15-0.25 mm, tooling $8,500-$12,000. Vacuum port with one-way check valve: softer Shore A 35-45 valve, tooling $10,000-$14,000 plus valve tooling. All three cleared at ≥ 2,000 open-close cycles pre-ship.

The closure is the single component that determines retail positioning, tooling cost, and defect exposure. Buyers evaluating a bag program should specify the closure geometry before the shell capacity.

Integrated slider zipper

Tongue-and-groove profile co-molded into the top rail of the bag shell, closed by a captive plastic or silicone slider that pulls the two rails together as it travels. Highest perceived retail value; matches the visual language of consumer plastic zip-top bags. Tooling requires a 4-cavity two-shot LSR mold with a rail insert — $12,000-$18,000 amortized against first order volume. CTQ: bead height ±0.05 mm; slider engagement force 3-8 N throughout travel; zero air leak at 10 kPa pressure differential for 60 seconds.

Press-seal channel

Interference-fit crush channel with 0.15-0.25 mm crush, closed by finger pressure running the length of the seal. Lower perceived retail value; matches the visual language of vacuum-sealed pouches. Tooling on a single-shot compression or injection tool — $8,500-$12,000. CTQ: channel width tolerance ±0.03 mm; opening force 4-9 N; zero air leak at 5 kPa for 60 seconds.

Vacuum port with silent one-way check valve

Integrated silicone check valve (Shore A 35-45, softer than shell) at the top or side of the bag, allowing air evacuation with a hand pump or vacuum sealer. Premium tier — sous vide, meal prep, dry goods storage positioning. Tooling for the shell $10,000-$14,000 plus a separate 8-cavity valve tool at $6,000-$9,000. CTQ: valve seat concentricity ±0.02 mm; opening pressure 2-4 kPa; sealing pressure ≥ 20 kPa without leak.

Closure comparison matrix

Closure system	Tooling cost	Retail tier	Cycle life	Per-unit add cost
Press-seal channel	$8,500-$12,000	Mass ($8-14)	≥ 2,000 cycles	Baseline
Integrated slider zipper	$12,000-$18,000	Premium ($14-25)	≥ 3,000 cycles	+$0.35-$0.60
Vacuum port + check valve	$16,000-$23,000 combined	Premium ($20-40)	≥ 5,000 cycles	+$0.55-$0.95

MOQ tiers and FOB Yantian pricing benchmarks

Wetop's MOQ is 500 pieces per SKU — the floor at which per-batch third-party test report economics (FDA + LFGB + Prop 65 + PFAS at ~$1,100-$1,500 combined) amortize acceptably. FOB Yantian Q3 2026 benchmarks for a 500 ml platinum-cure LSR bag with integrated slider and 1-color debossed logo: 500 pcs $3.20-$4.10, 1,000 pcs $2.60-$3.30, 5,000 pcs $2.00-$2.55, 10,000 pcs $1.75-$2.20, 20,000+ $1.50-$1.90. Tooling for a new slider geometry $12,000-$18,000 amortized against first-order volume.

Bag pricing runs 60-80% above baking mat pricing at equivalent MOQ tiers because injection cycle time is longer, closure QC is more labor-intensive, and closure cycle-life testing adds an inspection cost per batch. The MOQ math also holds harder — below 500 pieces per SKU the per-batch test cost dominates the finished per-unit price to the point where the product isn’t retail-competitive at any margin.

Full MOQ-tier FOB Yantian pricing (500 ml integrated slider, Q3 2026)

Volume tier	Peroxide HCR (post-cured)	Platinum LSR (co-molded)	Vacuum-port valve add	Frosted shell add	Pantone master-batch add
500 pcs	$2.80-$3.60	$3.20-$4.10	+$0.85-$1.10	+$0.10-$0.15	+$0.15-$0.20
1,000 pcs	$2.30-$2.90	$2.60-$3.30	+$0.75-$0.95	+$0.08-$0.12	+$0.12-$0.17
2,500 pcs	$2.00-$2.50	$2.25-$2.80	+$0.65-$0.85	+$0.07-$0.11	+$0.11-$0.15
5,000 pcs	$1.75-$2.25	$2.00-$2.55	+$0.55-$0.75	+$0.06-$0.10	+$0.10-$0.14
10,000 pcs	$1.55-$1.95	$1.75-$2.20	+$0.45-$0.65	+$0.05-$0.09	+$0.08-$0.12
20,000+ pcs	$1.35-$1.70	$1.50-$1.90	Quote	Quote	Quote

Prices exclude retail packaging (a color header card with backing runs $0.22-$0.45 per unit fully assembled), certification fees for a specific retailer scope, and destination-country duties.

Tooling investment for custom closures and capacities

• Small capacity (250-350 ml) with press-seal channel: $7,500-$10,000
• Standard capacity (500 ml) with press-seal channel: $8,500-$12,000
• Standard capacity (500 ml) with integrated slider zipper: $12,000-$18,000
• Standard capacity (500 ml) with vacuum port: $16,000-$23,000 (shell + valve tooling combined)
• Large capacity (1000-1500 ml) with slider: $14,000-$22,000
• Extra-large / stand-up gusseted: $18,000-$28,000

Tooling is a one-time cost that Wetop typically amortizes against the first production order rather than billing as a separate line — the amortization is baked into a slightly higher per-unit price on the first 5,000-10,000 pieces, then unit price drops on re-orders. Full pricing structure detail on the silicone OEM pricing structure guide and the MOQ economics logic on the real factory MOQ math guide.

Lead time from RFQ to warehouse — what’s realistic

Total realistic lead is 75-110 days from RFQ to US warehouse receipt. 10-18 days for sample on existing tooling (4-6 weeks if new closure tooling required), 40-55 days for production of 5,000-20,000 pieces after PO and 30% deposit, plus 14-18 day Yantian-to-US-West-Coast sailing (25-32 days East Coast, 30-38 days Northern Europe). Suppliers quoting 40-day cold-start-to-warehouse totals for a bag SKU are compressing tooling validation, post-cure, or closure cycle-life testing — often all three.

Lead-time compression on bag programs is a stronger red flag than on flat-sheet products because the closure system requires distinct validation steps that can’t be truncated without shipping downstream defects. The four places suppliers cut corners:

1. Skip closure cycle-life testing. ≥ 2,000 open-close cycles on an automated fixture takes 8-16 hours per lot. Skipping saves the fixture time and creates the field-failure defect complaint.
2. Skip or shorten post-cure. 4-6 hours of oven time at 180-200°C per batch is the LFGB §30/§31 compliance step. Skipping saves 20-30% oven energy and ships product that fails EU premium retail audit — plus generates first-heat odor at the closure bead.
3. Skip incoming raw material QC. Master-batch lot verification catches ~1-2% of upstream compound-house defects. Skipping creates traceability gaps.
4. Skip pre-shipment AQL inspection. ISO 2859-1⁸ AQL 1.5 sampling on a 5,000-piece bag batch takes ~6-10 hours by a qualified inspector.

The full RFQ-to-PPAP workflow at Wetop

Stage	Duration	Key deliverables	Buyer approval gate
1. RFQ receipt & engineering review	2-3 business days	Closure recommendation, cure recommendation, spec confirmation, price bracket	—
2. Sample production (existing tooling)	10-18 days	Physical sample + master-batch lot cert + Shore A + closure cycle test	Sample approval + PO
2b. New tooling cut (if custom closure or capacity)	+28-45 days (parallel where possible)	Tooling drawing + T1 first-article inspection + closure cycle-life report	Tooling approval
3. PO + 30% deposit + material procurement	5-10 days	Master-batch purchase, receiving QC	—
4. Production (5,000-20,000 pcs)	40-55 days	Injection or compression molding + post-cure + closure assembly + retail packaging	—
5. In-process QC + AQL 1.5 pre-shipment	+4-7 days (overlaps production)	FDA + LFGB + Prop 65 reports, PFAS non-detect, closure cycle-life, AQL inspection	Buyer inspection sign-off
6. 70% balance + shipping documentation	2-3 days	Commercial invoice, packing list, B/L, COO, MSDS, EU 1935/2004 declaration	—
7. Yantian to destination sailing	14-38 days depending on port	On-board notification, tracking	—
Total realistic	75-110 days

Full breakdown of the timeline drivers on the MOQ and lead time on silicone OEM guide.

Factory audit checklist — what retail buyers actually verify

The retail-audit checklist for bag programs reduces to seven documents plus one video verification. ISO 9001 certificate with silicone-molding scope; FDA + LFGB test reports per master-batch lot from the last 6 months; California Prop 65 Chapter 6 heavy-metals declaration; PFAS non-detect per batch; post-cure oven log for that same batch; closure cycle-life report; business + export license copies. Plus a 2-3 minute unedited walk-through video of injection cells, post-cure ovens, and closure QC stations. Resistance to sending any of these is the audit answer.

Consumer coverage of silicone bags obsesses over “how the closure feels in hand”. B2B retail audit obsesses over “how the factory documents that the closure will still feel that way at cycle 2,000”. The latter determines whether the product will pass retailer QA on the receiving dock in 90 days.

The seven-document audit stack

1. ISO 9001:2015 certificate — current validity date, silicone injection and compression molding in scope, issued by a recognized certification body (SGS, TÜV, Bureau Veritas, DNV, DEKRA). Verify against the certification body’s public register.
2. FDA 21 CFR 177.2600 + LFGB §30/§31 test reports — referencing a specific master-batch lot number from production in the last 6 months. Reports issued by SGS, Intertek, TÜV, or Bureau Veritas. Quantitative extractables values, not just pass/fail.
3. California Prop 65 Chapter 6 heavy-metals declaration — lead, cadmium, mercury, arsenic tested at ppm detection limits per master-batch lot.
4. PFAS non-detect test report — per-batch analysis at ppb detection limits from an accredited lab. Accelerating requirement given the ECHA restriction proposal⁵.
5. Post-cure cycle log — batch temperature-time record from the oven PLC or manual logbook, referencing the same master-batch lot. 180-200°C for 4-6 hours per batch, retained for 36 months minimum per ISO 9001.
6. Closure cycle-life report — automated open-close fixture results at ≥ 2,000 cycles with no seal degradation, referenced to the master-batch lot.
7. Business license + export license copies — verify legal entity name matches the trade partner on commercial documents.

The single video verification worth 10 documents

Request a 2-3 minute unedited walk-through video of the injection and compression molding floor with the current date shown (holding a printed daily newspaper or shift log). A working silicone bag OEM factory has:

• 6-16 active injection or compression molding cells (depending on scale)
• Two-shot LSR tooling visibly rigged for platinum-cure programs
• Post-cure ovens with batches inside (not empty)
• Raw material staging with visible master-batch lot labels
• Automated closure cycle-life test fixtures in the QC bay
• Secondary process area with printing, deburring, and packaging in progress

Full sourcing-verification framework on the sourcing silicone factory checklist.

Private-label vs OEM vs ODM — the decision matrix for buyers

The three sourcing models differ by documentation depth and design ownership, not by manufacturing quality. Private-label: our existing tooling library (500 ml, 1000 ml, 1500 ml capacities with slider or press-seal closure), your logo — no tooling investment. OEM: your CAD or reference bag, we cut new tooling ($8,500-$23,000), you own the design. ODM: we develop the SKU from a brief, you license the resulting design. All three at MOQ 500. Choose by whether retail differentiation needs to be design-level or brand-only.

The private-label / OEM / ODM distinction on bag programs is heavier than on flat-sheet products because the closure geometry is the single largest driver of retail differentiation — and closure tooling is where the OEM cost lives.

Decision matrix by program archetype

Program type	Private-label	OEM	ODM
Design ownership	Factory	Buyer (you)	Shared / licensed
Tooling cost	$0 (existing library)	$8,500-$23,000	$0 (shared library) or licensed
Time to first sample	10-18 days	45-70 days (tooling cut + T1 validation)	10-18 days
Best for	Fast-launch retail SKUs, private-label brands	Differentiated retail line, exclusive closure geometry	New brands, category test, limited-run
MOQ	500 pcs	500 pcs	500-1,000 pcs
Design exclusivity	No	Yes (buyer owns tooling)	Negotiated
Retail differentiation ceiling	Logo + color + packaging	Full design + closure + capacity + template	Full design + brand narrative

Wetop’s baseline bag tooling library covers: 250 ml (small snack), 500 ml (sandwich standard), 1000 ml (quart), 1500 ml (half-gallon), 2000 ml (gallon) — each available in press-seal channel or integrated slider closure at 500-piece MOQ under private-label with debossed or printed logo customization.

Full workflow detail on customize silicone logo — deboss, print, or laser and the private-label silicone kitchen products guide.

CTQ inspection points — the seven defect modes on silicone bags

Seven defect modes account for ~90% of retail return complaints on silicone food storage bags. Slider bead height variance beyond ±0.05 mm; press-seal channel interference outside 0.15-0.25 mm; wall thickness variance beyond ±0.08 mm; under-cure at the closure bead; vacuum-port valve durometer wrong (should be Shore A 35-45); delamination of secondary-bonded closure on peroxide-cure product; debossed logo pigment migration during post-cure. All catchable at AQL 1.5 sampling per ISO 2859-1[^iso-2859-1] pre-shipment.

The seven defect modes catalogued

Defect 1 — Slider bead height variance beyond ±0.05 mm. Inconsistent slider engagement force, uneven seal, air leak at low pressure differential. Cause: mold cavity wear, unequal LSR shot volume across cavities, or slider tolerance stack-up. Detection: optical comparator 5-point sampling per lot; slider engagement force measurement 3-8 N throughout travel.

Defect 2 — Press-seal channel interference outside 0.15-0.25 mm crush. Below 0.15 mm: won’t stay closed. Above 0.25 mm: won’t open without deformation. Cause: mold surface wear, gum viscosity drift, or press temperature drift. Detection: feeler-gauge sampling, opening-force measurement 4-9 N.

Defect 3 — Wall thickness variance beyond ±0.08 mm. Collapse under vacuum evacuation, split at fold lines during freezer service, uneven service life. Cause: mold flow imbalance across cavities, gum weight variance, or press stroke drift. Detection: ultrasonic thickness gauge 8-point sampling per bag.

Defect 4 — Under-cure at the closure bead. First-heat odor at the sealing surface, LFGB §30/§31 failure on the closure profile even when the shell passes. Cause: cycle time too short at the bead where thermal mass is highest, or missing post-cure. Detection: LFGB §30/§31 organic volatile testing³ on isolated bead samples plus organoleptic panel testing.

Defect 5 — Vacuum-port valve durometer wrong. Valve too hard (>Shore A 45) won’t open at 2-4 kPa; valve too soft (<Shore A 35) won’t seal at 20 kPa. Cause: wrong master-batch to valve tooling, or cross-contamination during two-shot LSR. Detection: ASTM D2240² durometer check on every valve batch.

Defect 6 — Delamination of secondary-bonded closure on peroxide-cure HCR. Closure profile separates from shell under repeated flex. Cause: bonding primer contamination, under-cure at bond interface, or thermal shock. Detection: destructive peel test (target ≥ 3 N/mm) plus 20-cycle thermal shock at -40°C to 100°C.

Defect 7 — Debossed logo pigment migration during post-cure. Logo appears yellowed, grey, or mottled instead of clean color. Cause: pigment migration at 180-200°C post-cure, incompatible pigment chemistry, or contaminated master-batch. Detection: D65 daylight-simulation light-box color check per ISO 2859-1; ΔE ≤ 2 against approved sample.

Pre-shipment inspection deliverables

Every Wetop bag batch ships with a pre-shipment inspection report covering:

• AQL 1.5 sampling plan per ISO 2859-1⁸
• Wall thickness ultrasonic gauge (8-point per sample)
• Shore A durometer check per ASTM D2240² on shell and (where applicable) valve
• Closure cycle-life test result (≥ 2,000 cycles, zero degradation)
• Air-tightness test (10 kPa differential, 60 seconds, zero leak)
• FDA + LFGB test report referencing the master-batch lot
• California Prop 65 heavy-metals declaration referencing the same lot
• PFAS non-detect test report referencing the same lot
• Post-cure oven log for the batch

Sample buyers running their own third-party pre-shipment inspection (SGS, Bureau Veritas, TIC, or in-house QC) can arrange it directly with the factory at any point in the production timeline.

What Wetop OEMs on silicone food storage bags

Wetop runs silicone food storage bag programs at 500-piece MOQ per SKU on both cure systems from a 7,500 m² founder-led Dongguan floor. Platinum-cure LSR for EU premium, PFAS-free positioning, infant-tier programs, and any retail program at $12+ shelf. Post-cured peroxide-cure HCR for US mass-tier retail accessory programs at $8-14 shelf. Per-batch FDA 21 CFR 177.2600 + LFGB §30/§31 + Prop 65 heavy-metals + PFAS non-detect test reports plus closure cycle-life documentation included in every quote.

Program defaults:

• Platinum-cure LSR (two-shot co-molded closure) — for EU premium retail, PFAS-free marketing, infant-tier programs, sous vide / meal-prep positioning, and any multi-year brand program where regulatory-drift insurance matters.
• Post-cured peroxide-cure HCR (secondary-bonded closure) — for US mass and mid-tier retail programs at $8-14 shelf, with PFAS-free process aids verified per batch, mandatory 4-6 hour post-cure at 180-200°C on every lot, and destructive peel testing on the closure bond per batch.

Tooling library covers 250 ml, 500 ml, 1000 ml, 1500 ml, 2000 ml capacities in press-seal channel or integrated slider closure at private-label MOQ 500. Custom tooling for OEM programs $8,500-$23,000 amortized against first order depending on closure geometry.

Sourcing a silicone food storage bag program? Email inquiry@wetopsilicone.com with your target retail tier, target regulatory scope (US-only, EU-inclusive, medical-adjacent, infant-tier), preferred closure system (or ask for recommendation), preferred cure system, and target volume — we return within 2 business days with a closure and cure recommendation, per-batch documentation packet outline, and price brackets at MOQ 500 / 1,000 / 5,000 / 10,000. Mutual NDA available at our NDA page. Full manufacturing detail on the capabilities page; anonymized program archetypes at case studies; direct engineering contact via the contact page.

Footnotes

1. US Food and Drug Administration. 21 CFR 177.2600 — Rubber articles intended for repeated use. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-177/subpart-C/section-177.2600 — the primary US food-contact regulation Wetop tests every silicone bag master-batch lot against. ↩

2. ASTM International. ASTM D2240-15 — Standard Test Method for Rubber Property—Durometer Hardness. https://www.astm.org/d2240-15r21.html — the Shore A hardness measurement standard for shell and valve silicone. ↩ ↩² ↩³ ↩⁴

3. German Federal Institute for Risk Assessment (BfR). Recommendation XV — Silicones. https://www.bfr.bund.de/cm/349/xv-silicones.pdf — the technical standard behind LFGB §30/§31 organic volatile testing for food-contact silicone. ↩ ↩² ↩³

4. European Parliament and Council. Regulation (EC) No 1935/2004 — Materials intended to come into contact with food. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02004R1935-20090807 — the EU framework regulation for food-contact materials. ↩ ↩²

5. European Chemicals Agency. PFAS Universal Restriction Proposal. https://echa.europa.eu/hot-topics/perfluoroalkyl-chemicals-pfas — the regulatory action driving PFAS-free per-batch testing as table stakes on EU premium and US West Coast retail bag programs. ↩ ↩²

6. NSF International / ANSI. NSF/ANSI 51 — Food Equipment Materials. https://www.nsf.org/consumer-resources/what-is-nsf-certification/food-safety-certification — occasionally required for silicone food storage bags sold into commercial-kitchen adjacent channels. ↩

7. US Consumer Product Safety Commission. CPSIA — Consumer Product Safety Improvement Act. https://www.cpsc.gov/Regulations-Laws—Standards/Statutes/The-Consumer-Product-Safety-Improvement-Act — the US consumer product safety framework any infant-tier or children’s silicone bag program must certify against. ↩

8. International Organization for Standardization. ISO 2859-1:1999 — Sampling procedures for inspection by attributes. https://www.iso.org/standard/1141.html — the sampling standard behind AQL 1.5 pre-shipment inspection on every bag batch. ↩ ↩²