Unused electronic components can be damaged by electrostatic discharge (ESD) during handling or transport, before they are ever powered in a product. A statement that parts have never been installed answers a different question from how they were protected. Check the device's ESD information and the handling arrangements for the material being offered.
The useful purchasing question is specific: what protection applied when the components were removed from storage, handled, repacked and prepared for delivery? Neither an unused-condition description nor an ESD rating supplies that history.
Understand how a device can encounter ESD before use
ESD is a transfer of electrostatic charge between objects at different electrical potentials. It can involve a charged person or tool contacting a device, or charge on the device discharging when it contacts another surface. The device does not need to be operating in a circuit for those events to occur.
Texas Instruments' ESD application report, SSYA010A, describes these mechanisms and the need for protection during storage, transfer and shipment. Protection is an ongoing handling task, rather than something established by the words "never powered."
The EOS/ESD Association's introduction to ESD explains how contact and separation involving packaging can generate charge. This gives buyers a reason to ask about transfers between containers, even when the components remain unused. It does not establish that a particular transfer caused damage.
Read HBM and CDM ratings within their test scope
Human Body Model (HBM) and Charged Device Model (CDM) describe different component ESD test models. Keep the model name with any rating. A number copied without its model and applicable product reference is incomplete information for a handling review.
Information | What it describes | What it does not establish |
|---|---|---|
HBM classification or rating | Device sensitivity under the specified human-body discharge test model | Protection against every handling event |
CDM classification or rating | Device sensitivity under the specified charged-device discharge test model | Interchangeability with an HBM result |
Manufacturer ESD data | The identified product's documented test scope | The exposure history of the particular stock offered |
The Association's device-sensitivity and testing guide explains that these models cannot reproduce every possible ESD event. Their results help develop controls; they do not grant permission to handle parts without an appropriate controlled environment.
Use the complete manufacturer part number to locate the applicable product information. Ask the person responsible for ESD controls how that information applies to the actual operation. Do not turn a component rating into a claim that a supplier's warehouse or shipping process is qualified.
Ask about protection at each handling handoff
Identify any operation that takes the devices out of their existing protection. This may include counting, checking, transferring between carriers or repacking. Ask which procedure and protective materials applied, and whether the same protection continues into the delivered package.
TI's report discusses personnel and work-surface controls, together with protective containers for storage and transfer. A suitable package is part of that protection. It cannot supply the controls that were absent while the devices were outside it.
Use these focused questions when the offered stock has been handled or repacked:
Which original carrier and protective package remain, and which were replaced?
What ESD handling procedure applied during the change?
What identifies the replacement protective packaging and its intended use?
Which parts of the handling history are supported by records, and which are unknown?
Packaging color or a photograph is insufficient evidence of protective performance. Ask for the material identification or specification relevant to the packaging claim. Record a statement about the current package separately from a statement about earlier handling.
Keep moisture protection and ESD questions separate
A moisture-exposure record addresses a different concern from an ESD handling record. Ask how the actual packaging and procedure address each requirement that applies to the device. A moisture-related label or humidity-card observation should not silently become an ESD conclusion.
Use the separate MSL storage guide for moisture-sensitive handling questions. This ESD review does not prescribe drying, baking or a replacement packing process.
Assess the claim without inventing a damage finding
Consider a hypothetical offer described as unused components in a newly sealed protective bag. The seller can identify the present bag, but cannot describe the conditions during an earlier repacking operation.
Record both facts: the present packaging is identified, and the earlier handling conditions remain unknown. A new closure cannot establish those earlier conditions. Equally, the missing history does not prove that an ESD event occurred or that the parts are damaged.
Ask the responsible technical or quality reviewer to assess the unresolved handling concern against the intended use. Keep any product test information within its stated scope. A functional result alone is not a record of every handling event, and it should not be described as proof that no ESD exposure occurred.
Frequently asked questions
Can ESD damage happen before a component is powered?
Yes. Charge can transfer during contact or handling before the device is connected to an operating circuit. Never-powered status does not describe the electrical conditions around the device during those operations.
Does an HBM rating mean I can open the package on an ordinary desk?
No. The rating describes a specified test model. Have the ESD-control owner determine the appropriate environment, personnel controls and packaging for the operation instead of treating the rating as permission to remove protection.
Does "unused factory surplus" establish ESD-controlled handling?
No. It describes the stated prior-use condition. Ask separately about storage, handling and any repacking. Keep the supplier's supported information and unavailable history distinct.
Does a sealed moisture barrier bag prove ESD protection?
The moisture-related description alone does not answer that question. Identify the actual package and the protection it is specified to provide. Even suitable present packaging does not reconstruct what happened before sealing.
What should a buyer do when ESD handling history is unknown?
State the specific gap and refer it to the responsible reviewer before treating the handling requirement as resolved. Preserve appropriate protection during any further work. Do not replace missing information with either a damage accusation or an unconditional assurance.