You may not be aware of how Santen is working to protect the global environment in the manufacturing process of its flagship ophthalmic eyedrops. Santen, which specializes in the field of eye care, uses a total of approximately 520,000 tons of water annually in Japan and abroad in pursuit of high-quality products, of which only a very small amount is used to make its products.
Recognizing this, we have been working for many years to find ways to reduce the amount of water resources used throughout our eye drop production process.
In May 2021, we formulated our "Santen Vision for the Earth 2050," an environmental vision for the year 2050, in order to strengthen our business foundation to support sustainable growth while fulfilling our social responsibilities, based on the recognition that global environmental conservation is one of the most important issues common to all mankind. Based on this vision, in all countries and regions where we do business, we are working on our product manufacturing process to address two areas, "climate change countermeasures" and "environmental impact reduction," to realize a decarbonized society.
Here, we will introduce our efforts to reduce the use of water and energy, which are indispensable in the manufacturing process of eye drops.

How to recycle water, which we consider “life”

Santen manufactures approximately 400 million units of eye drops for medical and general use annually, at domestic and overseas plants.*1 At Santen, water is vital for the production of eye drops, and within the company there is keen awareness of the need to make "effective use of limited resources." Because eye drops are administered directly to the human body, we pursue a level of quality comparable to that of "injectable water", which among medical products requires the strictest quality control, from the raw material water to the water used to clean tanks and other facilities. This is the result of Santen's desire to deliver high-quality products to patients and consumers.

Santen today uses a total of approximately 520,000 tons of water per year, both domestically and internationally, with only a limited amount of that water being used in the final product. For example, the Noto Plant, which manufactures approximately 250 million bottles of products annually, uses only about 0.4% of the total amount of water used. Most of the water used at the plant is consumed either in the process of making high-purity water used as raw material for eye drops, or for cleaning and cooling in the preparation and filling of products, before finally being discharged as factory water.
Can we reduce water consumption by reusing this wastewater? Various studies and discussions are taking place within the company in response to this new challenge, and projects are underway both in Japan and overseas.

In Japan, in May 2022, the Noto Plant replaced the wastewater piping in the filter with a new system that enables the wastewater to be reused. This is expected to reduce water consumption by approximately 7,000 tons per year. The plant is also considering the reuse of water from the cooling system used in the production of eye drops. If realized, this is expected to further reduce annual water consumption by approximately 30,000 tons.

At the Suzhou plant in China, water recycling facilities have been installed in accordance with national regulations, and more than 90% of the water is already being reused. In addition, at the new Suzhou plant currently under construction, Japanese production engineers are involved in all phases of the project, from design and construction to installation of equipment, and are collaborating with local companies while utilizing the know-how they have accumulated in Japan.

5ml equivalent

Learn more about Santen's environmental impact reduction >

Aiming for decarbonization through conversion and reduction of energy used in factories

The production of eye drops in our factories also relies on energy resources. Electricity is mainly used to run the air conditioning and production facilities, while heavy oil A*2 and gas are used for the distillation process of water for production, heating, and temperature and humidity control of the air conditioning.
A significant amount of energy is used in every process, such as running air conditioning equipment 24 hours a day to maintain the cleanliness of the manufacturing environment and clean rooms (aseptic rooms), circulating water at high temperatures to prevent contamination of high-purity water using thermal energy, and steam sterilizing manufacturing and filling equipment.

Santen is contributing to the realization of a decarbonized society through the conversion of energy sources and reduction of CO2 emissions at its plants and facilities. When updating facilities at its plants, Santen introduces efficient equipment that utilizes the latest technology while addressing cost effectiveness.

At the Noto Plant, for example, we introduced an inverter turbo refrigerator with higher energy consumption efficiency (COP) to replace the steam absorption refrigerator required for chilled water production, resulting in significant energy savings and a reduction in environmental impact through converting from fossil fuels to electricity. The annual energy saving effect was a reduction of about 900 kiloliters of crude oil equivalent (an approximate 30% reduction) in the amount of A fuel oil used.

The Shiga Product Supply Center (PSC) has been working to convert to a combination of electricity and gas for the chilled water facilities in the first and second buildings, respectively. First, when replacing the aging chillers in the second building, the energy source was switched from gas to electricity (a heat pump system). This was because electricity has approximately four times higher energy consumption efficiency (COP) than gas, and emits less CO2. Furthermore, since the water usage efficiency has also been improved, excess cold water is fed to the cold water system in the first building, reducing the operation of the conventional gas chillers and creating a backup system in the event of a breakdown. As a result, CO2 emissions were reduced by 360 tons/year (an approximate 5% reduction) and water consumption by 20,000 m3/year (an approximate 20% reduction).

This was the first such conversion at a Santen plant, with few examples to be found anywhere in industry, and the construction work was carried out in close cooperation with the power company from the design stage. As a result of the successful electrification of the refrigeration system and the conversion to a combined use of interconnection and gas, which took around one year to complete, Shiga PSC received the FY2019 Chairman's Award from the Kinki Electricity Utilization Rationalization Committee for its "contribution to the realization of a low-carbon society through the rational and effective use of electricity”.
Overall, by switching to renewable energy sources for all purchased electricity at plants and laboratories in Japan from January 2022, in combination with other measures, CO2 emissions in FY2021 were reduced to approximately 30,000 tons, a 13.7% decrease compared to the base year of FY2019.

A heavy petroleum product

Contributing to the Global Environment through Individual Efforts

Commenting on these changes, the project lead of the Shiga PSC, who played a central role in converting its chilled water facilities to electric power and using excess chilled water, said, "At the Shiga PSC, we are always conscious of whether there is any waste in our daily operations and whether there are areas that can be improved, and we bring together ideas from all over the world to address various challenges. Santen has implemented an improvement proposal system at production sites and lines, and we receive more than 4,000 improvement proposals from employees every year, including ideas that lead to global environmental conservation. When we see the real-world impact of energy and cost reductions, it gives us a real sense of accomplishment, which motivates us even more. It is also satisfying for me to feel that I am making a contribution both to the company and to the global environment."

The head of the Global Manufacturing Division, who leads the internal task force team for the realization of the "carbon neutral factory," noted, "At Santen, we are all working with a conviction that the activities we pursue to decarbonize and reduce water resource consumption will surely lead to global environmental conservation in the future, and that these activities will be passed on to the next generation, for many years to come. We believe that Santen's strength lies not only in our engineering staff who learn and accumulate experience by themselves so that they can choose the best solutions, but also in the development and transfer of skills through on-the-job training."


Front-line staff address environmental problems based on keen awareness of the issues

Japanese know-how is shared with the Chinese team

Water facilities for manufacturing at the Noto Plant

Santen will continue to work on reducing resource consumption and replacing resources used in its business activities in Japan and abroad by meticulously accumulating a wide range of ideas for global environmental conservation.
Learn more about Santen's climate change initiatives >

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