Industrial Wireless Sensor Networks (IWSNs) have been increasingly adopted in process automation due to a number of advantages such as cost reduction and enhanced flexibility. Nevertheless, transmission over wireless channels in industrial environments is prone to interference, resulting in frequent erroneous packet deliveries. Existing IWSN standards based on the IEEE 802.15.4 specification only prescribe Automatic Repeat Request (ARQ) for packet retransmission, without providing any means for error recovery, which leads to unexpected transmission delay. Forward Error Correction (FEC) code as an alternative approach is able to effectively improve reliability and reduce the number of retransmissions. However, FEC computation requires extra memory and processing time. In this paper, we discuss the timing constraints of employing FEC codes for IWSNs according to the IWSN standards. Then we benchmark a number of different FEC codes in a typical wireless sensor node in terms of memory consumption and processing time. Our results show that LDPC and Turbo code, as the state of the art FEC codes, fail to fulfill the requirement from the IWSN standards while other FEC candidates, such as RS code, are proven to be suitable for the practical implementation in IWSNs.