Protease ST-4L (cleaning)

An Enzyme Supplies alkaline liquid protease for laundry detergents


Protease ST-4L is an alkaline liquid protease for use in biological detergent products (both laundry and dishwashing). The product acts by hydrolyzing insoluble protein soiling into soluble peptides and amino acids which can then be readily removed from clothing fabric or dishes. Protease ST-4L is particularly effective at removing common household soiling such as blood, grass, milk, gravy and blood.
Protease ST-4L is a particularly high strength enzyme derived from a genetically modified strain of Bacillus subtilis, and works in conjunction with the other laundry and dishwashing chemicals to remove most protein based stains under a broad range of conditions.

Typical Characteristics

Activity minimum 38,000 GSU/g

Appearance – brown liquid

Bulk density 1.2g/ml


Protease ST-4L is available in bulk and in 200Kg or 25Kg jerry cans


Protease ST-4L has excellent long-term storage properties. To maintain optimum activity, store at moderate temperatures (below 25 deg C), in the original containers and with the lid closed.


Inhalation of aerosols from liquid enzymes should be avoided. Open in a well-ventilated environment. In case of accidental spillage or contact with skin/eyes, promptly rinse with water for at least 15 minutes. For more detailed information please refer to the Material Safety Data Sheet for this product


Protease ST-4L is active over a broad range of pH values from 7 – 12, with an optimum of pH 10. The enzyme is also active over a broad temperature range from 25 degrees C to 60 degrees C, with an optimum performance at 40 degrees C.

Quick Delivery, Worldwide

…from our own exclusive facilities, and top quality production partners in the UK, EU and Far East

Our Expertise

We have greatly benefitted from working with Enzyme Supplies, and we recommend their thoroughly professional service to anyone seeking technical expertise and a reliable, reputable source of industrial enzyme products.”

We have been supplied by Enzyme Supplies for over 3 years and have found their material and service very satisfactory. On one occasion they helped to supply at very short notice when another supplier let us down which could have resulted in very serious disruption.

have been working with Enzyme Supplies over the last twelve months and am extremely grateful for their expert advice, consistent and reliable service and most importantly, the ability to meet the continuing demands of my business, particularly in the area of API sourcing.  They continue to assist me with this key function and are willing to provide additional services when needed which may arise from time to time. I highly recommend using Enzyme Supplies to future customers and appreciate their ongoing support for our business

Enzyme Supplies’ has been supplying us with a range of enzymes for over 3 years…consistently high quality…competitive… efficient…will continue to use Enzyme Supplies as it’s supplier of enzyme

We changed from one of your competitors and now purchase our enzymes from Enzyme Supplies. The improvement in lead time has been fantastic and your service is excellent. Any question has been answered promptly and with a deep understanding of the material you provide, this did not happen with our previous supplier. I have already told you that I intend our relationship will be a long term one’.

Get Advice on Protease ST-4L (cleaning)

Tell us a little about what you need, or hope to achieve with enzymes, and we’ll get back to you just as soon as we can. By email, or if you prefer by phone or zoom

    Request a sample

    To request samples, select a product on our website and click request a sample. If you are unsure, then just call, or mail us at to request a call back from an industry expert

    Please note we cannot supply samples to the general public. If you are a start-up then please contact us to discuss samples

    Request a sample