Efforts for environmental protection

Decreasing amount and optimum treatment of waste

The scarcity of final waste treatment facilities has been discussed as a problem of industrial waste treatment. In addition to this, the pollution of ground water and soil by toxic substances contained in waste has become a recent social problem. Considering this situation, the amended Waste treatment law came into effect in 1997~1998. The major purpose of this law is to control the generation of waste, guaranteeing optimum treatment. Adhering to this law, OKI is making the following efforts to control the generation of waste and to provide optimum treatment of waste. Changes of factory waste amounts (including semiconductor manufacturing affiliated companies)

1. Decreasing amount of waste generated at factories

To decrease the amount of factory waste (general waste and industrial waste) generated at factories, waste reduction/recycling promotion sessions were established, which takes the following three approaches.
Semiconductor manufacturing affiliated companies, which generate a high volume of waste, participate in these sessions to make efforts along with Oki Electric Industry.
(1)Controlling generation of waste by reviewing and improving manufacturing processes
Alcohol based chemicals were changed to alkaline based chemicals at semiconductor factories, which allows waste to be treated and decreased within a company, and as a result, the amount of waste decreased by approximately 460 tons.
(2)Reusing and recycling generated waste

In semiconductor manufacturing processes, sulfuric acid used once is collected and regenerated for reuse.
By using sludge as a cement material, waste was decreased by approximately 500 tons.
(3)Decreasing the volume of disposable waste so as to decrease the burden of waste treatment facilities.

To decrease the volume of waste plastic, volume reduction machines (see photo at right) were installed.
By increasing the dehydration rate, the volume of sludge was decreased.
Measures to decrease major industrial waste

Classification Measures

Sludge Used as cement material, used as fertilizer

Waste oil Used as fuel

Waste acid Recycled (reuse)

Waste alkali Decreasing amount by in-house treatment

Waste plastic Recycled (reuse), used as cement material

Installed waste plastic volume reduction machine

2.Optimum treatment of waste

The following were executed for the optimum treatment of waste.

An "optimum treatment management standard for waste" and "consignment standard for industrial waste treatment companies" were established and are now being executed.
The eligibility of used product treatment consignment companies in Japan was evaluated. We directed the following improvements for companies who did not reach the required eligibility level.