ESD bags (also called antistatic or static bags) package static-sensitive electronic parts and come in three types by mechanism: antistatic bags that only reduce their own charging, conductive bags that let charge drain away, and shielding bags that block external electrostatic fields. What you can actually buy are four bag types: pink PE antistatic bags, black conductive bags, silver-gray shielding bags, and foil moisture barrier bags (MBB) that both shield and keep out moisture.
This article is the buying overview for the family. For ready-made shielding bags by the pack, see ESD shielding bags (open-top and zip-lock, 142 sizes); for foil bags (ESD and standard versions, single-color printing available), see antistatic foil bags; for foil bag structure, moisture vapor transmission, heat sealing and standards, see antistatic foil bags explained; for the moisture-proof packing process, see PCBA moisture barrier packaging; and to measure surface resistance yourself, see how to measure antistatic values properly.
A common request when buying packaging is “give me ESD bags.” The problem is that an “ESD bag” is not one kind of bag but three materials solving different problems — low charging, conductive grounding and electrostatic shielding. Buying the wrong one doesn’t hurt right away; it shows up later in a failure analysis report at the customer. This article explains the differences, how to judge between them, and when you must step up to foil bags.
1. Three bags that solve three different problems
| Type | Problem it solves | Typical look | What it can’t do |
|---|---|---|---|
| Antistatic (low charging) | Reduces static generated by the bag itself when rubbed or pulled out | Pink, translucent | Provides no grounding path and doesn’t shield external fields |
| Conductive | Provides a low-resistance path for charge to drain away | Black, carbon-loaded | Conductive does not mean shielding (see Section 3) |
| Shielding (shielding / MBB) | Blocks external electrostatic fields, and also blocks moisture and light | Silver-gray foil laminate | Costs more; may not be needed for short moves inside the plant |
First check how far your material travels: if it only moves within the plant’s EPA (ESD protected area), antistatic or conductive materials are usually enough; once it leaves the EPA (shipping, outsourcing, long-term storage), it must have electrostatic shielding.
2. How surface resistance is classified
Materials are classified by surface resistance. ANSI/ESD S541 defines static dissipative material as surface resistance ≥1.0 × 10⁴ Ω and <1.0 × 10¹¹ Ω; below this range is conductive and above it insulative.
In purchasing, just remember the direction: too low (conductive) and charge moves too fast, which can be risky in direct contact with sensitive devices; too high (insulative) and charge can’t move at all, so the material stays charged after rubbing. The inner layer in direct contact with components should fall in the dissipative range. The inner layer of JIAHON’s antistatic foil bags is labeled 10⁶ to 10⁹ Ω (customizable down to 10⁶ Ω; no test report attached), a labeled range within that band.
3. A common misunderstanding: black conductive bags don’t shield
Many people treat black conductive bags as “high protection,” which is wrong. Shielding is judged not by color but by measured energy penetration: under ANSI/ESD STM11.31, a passing shielding package must be below 50 nanojoules (nJ). Black conductive bags are not shielding bags and are not rated against that threshold.
The reason is simple: a conductive material provides a path for charge to drain away, while shielding needs a metal layer to keep external fields out. They are different physical mechanisms. To shield, you need a metal layer — which is exactly the value of foil laminate bags.
4. The three layers of a foil bag, each with its own job
A foil bag (MBB, moisture barrier bag) gets its protection from a multilayer laminate: an outer PET layer for tear resistance, a middle aluminium foil layer that blocks UV, moisture and gases, and an inner antistatic PE layer for ESD protection. Each layer has a function, which is why “metallic sheen” does not equal “a proper foil bag.” For published layer thicknesses, moisture vapor transmission and heat sealing conditions, see antistatic foil bags explained. For a comparison of JIAHON’s ESD and standard foil bag versions, see the table on the antistatic foil bags page.
What buyers often overlook is puncture resistance and seal strength. If a bag tears or a seal splits, a good surface resistance value means nothing — for long-distance transport or heavy stacking, check these two before resistance.
5. When you must step up to a foil bag
Three checkpoints; if any applies, don’t economize:
- Material leaves the EPA: shipping, outsourcing or moving between plants — with no static control along the way, the packaging itself must shield.
- Components are moisture-sensitive: moisture-sensitive devices (MSL) need moisture barrier packaging with desiccant and a humidity indicator card; see What is MSL? J-STD-033 packaging, exposure time and baking explained.
- Long-term storage: open-top bags can be sealed with a heat sealer or vacuum sealer after evacuation; with a six-spot humidity indicator card, you can tell on opening whether moisture got in during storage.
6. Sizes and customization
To choose a size, see the foil bag size lookup table (24 listed sizes; those marked for online ordering can be ordered directly). For custom bags, adjustable items include special sizes (from 4 × 6 cm to 40 × 50 cm and above), thickness, single-color logo printing (lot number, warning text, symbols) and seal style (open-top, stand-up, zip-lock). Small quantities are accepted.
Smaller ESD shielding bags (outer size 5 × 8 to 60 × 80 cm, 142 open-top and zip-lock styles, packs of 100) are on the ESD shielding bags page, where you can choose by style and size.
FAQ
Can pink antistatic bags be used to ship ICs? Not recommended. Antistatic bags only reduce their own charging and don’t shield; once material leaves the EPA, use a shielding (foil) bag with a metal layer.
Why don’t black conductive bags count as shielding? Conductivity and shielding are two mechanisms. Shielding must pass an energy penetration test (threshold below 50 nJ); black conductive bags are not shielding bags and are not rated against that threshold.
Can foil bags be reused? Yes, but each heat seal uses up some of the opening, and the bag must be checked for pinholes or crease damage; for moisture protection, replace the desiccant and check the indicator card before reuse.
For ordinary hardware parts, do I need the ESD version? No. Non-static-sensitive materials can use the standard version; keep the budget for parts that really need ESD protection.
What are ESD bags made of? It depends on the type. Pink antistatic bags are mostly single-layer PE with an antistatic coating; conductive bags are carbon-loaded black material; shielding bags mostly contain aluminium or another conductive layer (the shielding bags on our site don’t state their metal layer); foil moisture barrier bags have three layers — dissipative polyester (or polymer) / aluminium foil / dissipative PE. Sources: an online article comparing antistatic and shielding bags; moisture barrier bag data sheets from three makers (1, 2, 3).
How do ESD bags work? The three types solve three different problems: antistatic bags keep the bag itself from charging but don’t block external discharge; conductive bags let charge drain away; shielding bags use a conductive layer to keep the energy of external discharge outside the bag. Materials are classified by surface resistance, with ANSI/ESD S541’s dissipative range at ≥1.0 × 10⁴ Ω and <1.0 × 10¹¹ Ω. Sources: the online comparison article above; an ESD products maker’s Q&A page on S541.
What is shielding effectiveness? It is a bag’s ability to keep external electrostatic discharge outside. The standard method is ANSI/ESD STM11.31, which measures discharge energy penetrating the bag wall in nanojoules (nJ); ANSI/ESD S541 sets the threshold below 50 nJ. Makers’ data sheets state different figures.
What are static bags used for? Packaging static-sensitive electronic parts such as circuit boards, ICs, graphics cards, memory modules and hard drives. If material only moves within the plant EPA, antistatic or conductive material is usually enough; if it leaves the EPA (shipping, outsourcing, long-term storage), choose bags with shielding; for moisture-sensitive devices, add a moisture barrier foil bag. Source: IPC/JEDEC J-STD-033D preview pages (dry packing of moisture-sensitive devices).
Where can I buy antistatic bags? Our site currently lists two types: ESD shielding bags (packs of 100, open-top and zip-lock) and antistatic foil bags (three-layer foil, single-color printing available). Pink PE antistatic bags and black conductive bags are not currently listed.
For plant-wide ESD layers (people, worktops, environment, packaging), see the complete ESD protection guide. To confirm size, thickness or printing, please contact JIAHON or email [email protected]; our technical sales team can help select by part and transport conditions.