The fact that two more of Japan's leading materials makers — Mitsubishi Materials and Toray Industries — have followed in the footsteps of Kobe Steel in admitting to falsifying quality test data on their products raises the question of whether the misconduct is isolated and limited to just a few firms. Keidanren (Japan Business Federation) Chairman Sadayuki Sakakibara, who headed Toray while the reported problems were taking place, said the group would call on its roughly 1,360 member companies to look into whether they have engaged in similar practices.

The companies whose subsidiaries have for years been manipulating test data when products did not meet contractual specifications say that safety was not compromised. The president of Toray, which learned of the data falsification at one of its units as long ago as July last year, said the firm would not have disclosed its problem had the Kobe Steel's case not surfaced in October. They should reflect on the impact such practices have on the trust their clients hold in them and international confidence in the quality control of Japan's manufacturing industries. The salient point is not the degree of falsification, or whether there was any practical damage to product quality, but that the cheating on product quality data was allowed to go on for so long.

Mitsubishi Materials said last week that three of its units — Mitsubishi Cable Industries, Mitsubishi Shindoh and Mitsubishi Aluminum — had been faking the data on products delivered to a total of about 270 companies in a variety of sectors such as automobiles and aircraft, ranging from rubber seals to brass strips for auto parts and aluminum sheets. Such practices are said to have been going on for years, and the head of Mitsubishi Cable said the firm kept shipping the products knowing that they may have problems after management learned of the misconduct in February.