IEC 61340-4-4 Ignition Testing of Type B and Pseudo-Type D FIBC
In the Type D FIBC Technology Monthly Newsletter for February 2024, we explained why Type B FIBC can never be a safe replacement for Type D FIBC. The first sequence in this video shows the testing of a Type B FIBC. In this case, the severity of the test parameters are reduced from the “worst case” conditions required by the international safety standard IEC 61340-4-4, to more closely match conditions that might be found in an end-use application, specifically expandable polystyrene (EPS) handling operations. The charging current applied during testing is reduced from 3 microamp to only 0.5 microamp. The gas mixture is adjusted to a minimum ignition energy (MIE) of 0.24 mJ, equivalent to pentane, a gas typically used as a blowing agent in EPS. The MIE specified in the IEC standard is 0.14 mJ. Even with one sixth of the amount of charge going into the bag, and with a gas that is almost twice as difficult to ignite, the video clearly shows that ignition still occurs.
In the second video sequence, IEC 61340-4-4 testing of a bag labelled as Type D is shown. The FIBC was obtained from the open market, and although it claims compliance with IEC 61340-4-4, an ignition is clearly seen, proving this to be a false claim. In fact, this particular FIBC had multiple ignitions on all sides. We refer to FIBC such as this as pseudo-Type D because they claim to be Type D, but fail to meet national and international safety standards for Type D qualification.