Specify the electrical property and test conditions before choosing anti-static PP board. Surface resistance is reported in ohms; surface resistivity reported in ohms per square is a different measurement. Low-charging behaviour, resistance and discharge shielding describe different properties, so one label or number does not establish complete ESD protection.
Define the packed item's sensitivity and handling environment with the ESD coordinator. Request evidence for the quoted grade, then agree qualification and periodic checks under the humidity, temperature, cleaning and wear expected in service.
Resistance categories and low-charging behaviour
- Conductive surface-resistance range: below 10⁴ Ω.
- Dissipative surface-resistance range: at least 10⁴ Ω and below 10¹¹ Ω.
- Insulative surface-resistance range: at least 10¹¹ Ω. This is not the definition of low charging.
These boundaries follow the terminology in ESDA's introductory definitions. Low charging concerns charge generation and cannot be inferred from a resistance category. State the acceptance range and method required by your control plan; do not turn the category limits into a universal target for every electronic item.
Permanent versus migratory — the part that decides service life
Ask how the proposed formulation achieves its properties and which measurements support them. Formulation descriptions help plan qualification, but they are not substitute test results.
Surface-active or migratory systems. Ask how humidity, storage, cleaning and surface wear affect the proposed grade. Qualify it under the specified service and conditioning cycle. Do not assign a fixed useful life, cleaning tolerance or resistance change from the additive category alone.
Bulk conductive or dissipative systems. Ask about the formulation, colour options and lot controls, then obtain the same conditioned and post-use measurements required for the application. A permanent label does not prove independence from humidity, abrasion, chemicals or ageing.
Choose between qualified proposals using the required electrical performance, cleaning and reuse cycle, contamination limits and total quoted cost. An untested formulation is not made suitable by selecting a permanent or single-trip label.
Verifying the claim
Three things to put in the purchase specification:
- Property and method. State the standard and edition, reported quantity, acceptance range, test voltage, electrodes, conditioning and temperature/humidity. For a surface-resistance requirement, confirm that the report uses an applicable method such as ANSI/ESD STM11.11 for suitable planar samples. Do not directly substitute a surface-resistivity, volume-resistance or resistance-to-ground result.
- Additional electrical requirements. If the control plan requires low-charging, charge-decay or discharge-shielding performance, name the method and criteria separately. A charge-decay test needs its charging and end voltages, timing and test arrangement; there is no universal voltage pair that qualifies all board and packaging.
- Retest after the service cycle. Agree cleaning agents, temperature, handling or abrasion, storage and the number of cycles to simulate. Record results and sample identity before and after conditioning, with rejection or retirement criteria. One test does not by itself establish the additive chemistry or lifetime.
Practical construction notes
Define the handling and grounding arrangement where charge dissipation is required, and assess the complete packaging outside the electrostatic protected area (EPA). ESDA's control principles explain the additional discharge-shielding property for packaging moving sensitive items outside an EPA. A resistance reading or a grounded bench alone does not qualify the whole protection system.
For contamination-sensitive parts, inspect the actual cut edges, joints and dunnage after fabrication and handling. Agree cleaning, edge finishing, particle or residue limits and the inspection method. Do not assume that every carbon-loaded panel sheds particles, or that another formulation is automatically clean.
Where it does not apply
Separate electrostatic field or discharge shielding from radio-frequency EMI shielding. Ask which property the package must provide, under which test and configuration; an EMI requirement also needs its frequency range and attenuation criteria. An anti-static or dissipative label alone does not establish either result. Qualify the complete arrangement, including closures, seams and any inner package.
Request an ESD packaging specification review. Provide the item and handling route, control-plan requirements, resistance property and method, conditioning, cleaning and reuse cycle, contamination limits, dimensions and quantity. Include existing reports so missing tests and quotation assumptions can be identified before ordering.