14
OctSingle-Use vs Stainless Steel in Biotech Manufacturing
In brief: Single-use systems are plastic bags, tubing and filters used for one batch, while stainless steel systems are fixed tanks and pipes cleaned and steamed in place between batches. A 2011 life-cycle study in BioPharm International, run by GE Healthcare, found 38% lower global warming potential in the use phase and 34% lower across the life cycle for single-use at 2,000 L, mostly because cleaning and steaming were removed. Stainless steel still runs bioreactors above 10,000 L, and many plants now go hybrid. The stainless water, steam and buffer lines in a hybrid plant still need cleaning, inspection, derouging and passivation, which Rouging Solutions provides from Ahmedabad.
Biotech teams argue about this before any equipment is ordered. Single-use bags promise faster changeovers and no cleaning. Stainless steel promises scale and a long working life. India's bioeconomy grew from about USD 10 billion in 2014 to over USD 195 billion in 2025 (PIB, 19 March 2026). So the choice matters to more plants each year. Here is how the two compare, and why many plants end up using both.
Key Takeaways
- Single-use systems remove most cleaning and steaming between batches.
- A 2011 study found 34% lower life-cycle emissions for single-use at 2,000 L.
- Stainless steel still runs the largest bioreactors, above 10,000 L.
- Many plants go hybrid, and their stainless loops still need rouge control.
Single-Use vs Stainless Steel: What Is the Difference?
Single-use systems are plastic bags, tubing and filters that are used for one batch and then thrown away. Stainless steel systems are fixed tanks and pipes that are cleaned and steamed between batches. So the single-use vs stainless steel choice comes down to cleaning, scale and waste, and each suits different work.
Stainless steel needs a lot of support to stay clean. A 2011 study in BioPharm International says this kind of kit "must be cleaned and steamed in place (CIP/SIP) between each batch". It adds that this takes "a large amount of process water, water for injection (WFI), acids, and bases" (BioPharm International, 2011). Our guide to CIP cleaning in pharma shows what one of those cleaning cycles involves.
Single-use parts skip most of that. They arrive ready to use, do one job, and leave as waste. In return, you get more plastic and a steady need for new parts. You also get new questions about what the plastic might add to the product.
How Do Single-Use and Stainless Steel Compare?
On cleaning, water and energy, single-use usually wins. On scale and waste, stainless steel usually wins. The table below sets out the main points side by side, using published studies. Treat the figures as a guide, because every plant's numbers depend on its own process, scale and power supply.
| Factor | Single-use | Stainless steel |
|---|---|---|
| Cleaning between batches | Mostly none, parts are replaced | Clean in place and steam in place every batch |
| Largest bioreactors | Up to 6,000 L in the newest plants reported | Above 10,000 L in running plants |
| Water and energy | Lower, with no CIP or SIP | Higher, CIP and SIP are the biggest load |
| Waste | Plastic, mostly burned or sent to landfill | Spent cleaning chemicals and water |
| Supplies | Needs a steady flow of new parts | Long life, with planned upkeep |
| Main quality risk | What leaches out of the plastic | Corrosion and rouge on the steel |
Some of the clearest numbers come from that 2011 study. It compared the two at 100 L, 500 L and 2,000 L. At 2,000 L, single-use showed "38% lower GWP during use phase (and 34% lower GWP across all life-cycle stages)". GWP stands for global warming potential. The study was run by GE Healthcare, which sold single-use systems, so weigh it with that in mind.
The same study found where stainless steel's footprint comes from. "The most substantial impacts (38-40% of both GWP and CED) are related to the support CIP/SIP system". CED means cumulative energy demand. In other words, the cleaning and steaming plant behind the tanks drives most of the load.
When Does Single-Use Make Sense?
Single-use makes most sense at small and medium scale, and in plants that switch products often. Clinical batches, new products and multi-product suites all gain from skipping cleaning between runs. It can also help a new plant start faster, because there is less fixed piping to build, clean and qualify.
The growth shows in the data. A 2025 review in Frontiers in Sustainability says single-use bioreactor capacity "has grown from 1% to 13% volumetrically". Their share of installed bioreactors rose from 30% to 46% over two decades, based on a 2016 estimate (Frontiers in Sustainability, 2025).
There are trade-offs to plan for. The same review says single-use needs "a steady supply of disposable components", so a late delivery can stop a line. It also warns about "migration of contaminants from plastic". This is the extractables and leachables question. QA will want data on it for every bag and tube.
When Does Stainless Steel Still Win?
Stainless steel still wins at large scale and for long runs of one product. The Frontiers review says steel plants are still running bioreactors "exceeding 10,000 liters". At that size, a tank can serve for many years. Its cost is then spread over a great many batches, which makes each one cheaper.
The gap is closing, though. The same review says most big commercial production "continues to rely on SST", which means stainless steel. It also says single-use plants for antibodies reached a new size in 2023. One was built with six 4,000-liter bioreactors, and a later one with ten 6,000-liter units.
Waste is the other side of the ledger. The same review says most of the sector's single-use plastic is still burned or sent to landfill, citing a figure of 30,000 tons. A plant with a strong waste or carbon target may count that against single-use.
Large vaccine and biosimilar runs can fall here. Take a plant in Genome Valley in Hyderabad, or in the Pune belt, that makes big volumes of a few products. It may find fixed steel cheaper and steadier over the long run. A plant that switches products often may find the opposite.
Why Many Biotech Plants End Up Hybrid
Many plants mix the two. Single-use bags handle the early steps and small volumes. Stainless steel handles the large tanks, the water and the steam. A BioProcess International piece on Amgen's approach puts it simply: "A hybrid option would help in extracting the best of both worlds" (BioProcess International, 2019).
The Frontiers review expects the same trend. It says makers will lean on single-use "through the provision of hybrid facilities". In practice, a hybrid plant still keeps its purified water system, clean steam lines and buffer tanks in stainless steel. Those are the parts that need care for as long as the plant runs. Our inspection and monitoring service checks them on a set schedule.
So the real question for many teams is which steps go single-use, and which stay in steel. Four questions help draw that line for each step:
- How big is the batch? Large volumes favor steel, and small ones favor single-use.
- How often does the product change? Frequent changes favor single-use, since there is less to clean.
- How much cleaning would the step need in steel? Heavy cleaning and steaming loads favor single-use.
- Can you get parts on time? A shaky supply of bags and filters favors steel.
What Does the Stainless Steel in a Hybrid Plant Need?
It needs cleaning, regular inspection and rouge control. Rouge is a corrosion film that forms on stainless steel. It often shows up in exactly the parts a hybrid plant keeps in steel: purified water systems, clean steam lines and buffer tanks. A plant that goes hybrid still needs a plan for that steel.
A 2010 article in Pharmaceutical Technology says rouge "ranges in color from reddish brown to blue or black" (Pharmaceutical Technology, 2010). It ties rouge to purified water, clean steam and buffer tanks. The author worked for STERIS, a firm that sells cleaning products.
The same article says what a plant should do. Plants "should have procedures in place for cleaning, derouging, and passivating new equipment". They should also check "in-use water systems and process equipment" on a regular basis. That matches our own practice: new steel needs passivation, and running loops need regular checks.
Hot steam lines need extra care. The article calls Type III rouge "Black-oxide rouge generated by high temperatures or steam". The article adds that full removal often needs a specific chemical treatment. Our guide to rouging in WFI systems explains how it forms, and our derouging service covers how it is removed.
We look after that steel at your site or at ours. As well as cleaning, derouging and passivation, we offer mechanical polishing and electropolishing. Each job comes with all the documents your auditor will ask for.
Where to Start
Single-use vs stainless steel is rarely an either-or choice. For many biotech plants, the answer is a mix of the two. The steel part of that mix still needs looking after for as long as the plant runs, because that is where rouge forms.
This week, list the steps you run in steel today and the ones you plan to move to single-use. Mark the water, steam and buffer lines that will stay in steel. Those are the lines to inspect first.
Our passivation team can inspect those lines and set a care plan. We reply within 24 hours.
Frequently Asked Questions
Is single-use always greener than stainless steel?
Not always. The 2011 study found lower emissions and energy for single-use at the scales it tested, mostly because there was no cleaning or steaming. But single-use creates plastic waste, and results change with the scale and the local power supply. Check your own numbers before you decide.
What is the largest single-use bioreactor size?
The 2025 Frontiers review reports single-use antibody plants built in 2023 with 4,000-liter and then 6,000-liter bioreactors. Stainless steel plants still run bioreactors above 10,000 liters. For the very largest volumes, steel is still the usual choice.
Do single-use systems need passivation?
No. Passivation is a treatment for stainless steel, and single-use parts are made of plastic. For single-use, the question is what the plastic might release into the product. QA usually asks the supplier for that data before a part is approved.
Does a hybrid plant still get rouge?
Yes, in its steel parts. The water, steam and buffer lines in a hybrid plant can still form rouge. Regular checks, derouging when needed and passivation of new steel keep it in check. Our guide to derouging frequency explains how to set the interval.
Which is cheaper, single-use or stainless steel?
It depends on scale and how often the product changes. Single-use saves cleaning, but you buy new parts for every batch. Stainless steel costs more to install and can serve for many years. Many plants find that a hybrid gives the best balance.
Sources. Flanagan et al., “An Environmental Life Cycle Assessment Comparing Single-Use and Conventional Process Technology”, BioPharm International (2011), for the scales, the GWP and energy results and the CIP/SIP load · Goggin et al., Frontiers in Sustainability (2025), for single-use adoption, stainless bioreactors above 10,000 liters, the 2023 single-use plants of 4,000 and 6,000 liters, high-volume production still relying on stainless steel, supply, migration of contaminants, waste and hybrid facilities · Cheryl Scott, BioProcess International (2019), for the hybrid quotation · Paul Lopolito, “Addressing Rouge in Biopharmaceutical Manufacturing Systems”, Pharmaceutical Technology (2010), for rouge, its types and the procedures quotation · Press Information Bureau, 19 March 2026, for India's bioeconomy figures. Every quotation was read on the source. The comparison table and the hybrid split are ours.