Active Medical Devices – Flammability of insulation/plastic materials

Fire events in health care facilities could result in tragic consequences.

To reduce the risk of such events occurring, manufacturers of medical electrical equipment are confronted with requirements from the standard 

IEC 60601-1:2005/AMD1:2012 and IEC 60601-1:2005/AMD2:2020 respectively, Medical electrical equipment – Part 1: General requirement for basic safety and essential performance 

regarding flammability and resistance to heat for used materials.

For the commonly used range of insulations and plastics it is very helpful that they often are certified and come with datasheets or entries in product or material approval databases to prove their classification of flammability. 

But what should be done if no evidence of certification or approval is available?

Chapter 11.3 of the standard offers the ability to demonstrate a flammability class of V-2 (or better) for

• connectors
• printed circuit boards and
• insulation material on which components are mounted

by testing three samples of the relevant parts according to the standard IEC 60695-11-10.

The EMC Testcenter AG in Regensdorf is equipped with a professional Flame-Tester and offers the facility for testing in accordance with

 IEC 60695-11-10 Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical flame test methods.

For testing of flammability class V-2 (or better) samples with dimensions of 125.0 mm (length), 13.0 mm (width) and 0.1 mm to 12.0 mm (thickness) are clamped on their upper end with the longitudinal axis vertical over a cotton pad. The lower end of the sample is then approached by the 50 W burner flame for 10 s. After 10 s the flame is removed from the sample. The time (t1) will be measured during which combustion of the sample persists after the ignition source has been removed.

Furthermore, burning particles or molten material drips falling from the sample will be noted and whether or not these ignited the cotton pad.

As soon as the flame on the sample extinguishes, the burner flame will be applied for a further 10 s. Following this second ignition, the time (t2) during which a flame persists on the sample, is measured. After the flame has extinguished the time (t3) is recorded until the sample ceases to glow. 

Burning of a sample in the chamber of the flame tester

The observations and measured times during testing serve to classify the material (according to the simplified table 2 of IEC 60695-11-10:2013)

• Afterflame time (t1, t2): ≤ 10 s (V-0), ≤ 30 s (V-1), ≤ 30 s (V-2)
• Second afterflame time plus afterglow time (t2+t3): ≤ 30 s (V-0), ≤ 60 s (V-1), ≤ 60 s (V-2)
• Afterflame and/or afterglow of the sample burned to the holding clamp: No (V-0), No (V-1), No (V-2)
• Cotton pad ignited by flaming particles or drips: No (V-0), No (V-1), Yes (V-2)

Are you, in the context of the development or certification of an electrical medical, interested in the testing of a material for the classification of flammability? If so, do not hesitate to contact us.