1. The Debate
Single-use vs stainless steel bioreactors is arguably the most consequential choice in biopharma facility design. This decision affects capital investment, operating cost, turnaround time, contamination risk, product flexibility, and environmental footprint — and the right answer depends entirely on your scale, batch frequency, and product portfolio. Below 2000 L and 20 batches per year, the disposable-bag option almost always wins; above 5000 L and 30 batches per year, stainless steel wins decisively. This article provides the cost data, crossover analysis and product-specific guidance to decide which is right for your facility.
The single-use bioreactor (SUB) market has grown at approximately 25% CAGR over the past decade, driven by clinical-stage companies that need flexibility and speed-to-clinic without massive capital outlays. But stainless steel still dominates at large commercial scale, where high batch volumes and decades-long product lifecycles make the upfront investment worthwhile.
Neither technology is universally superior. The question is: at what scale, batch frequency, and product type does the economics tip from one to the other? This article provides the data and framework to answer that question for your specific situation.
Single-use (SU): Bioreactor with a pre-sterilized, gamma-irradiated polymer bag as the product-contact vessel. Disposed after each batch. Also called "disposable." Major suppliers: Cytiva (Xcellerex), Sartorius (BIOSTAT STR), Thermo Fisher (HyPerforma), Merck (Mobius).
Stainless steel (SS): Traditional fixed vessels constructed from 316L stainless steel, cleaned in place (CIP) and sterilized in place (SIP) between batches. Reused for thousands of cycles.
2. Capital Cost Comparison
The capital cost advantage of single-use is dramatic. A single-use facility requires no CIP/SIP systems, minimal piping, simplified HVAC (no steam generation), and reduced cleanroom classification in many areas. The savings compound throughout the facility:
The facility timeline is equally different. A single-use facility can be designed, built, and validated in 18–24 months. A stainless steel facility typically requires 36–60 months. For a company racing to supply a newly approved product, this time difference can be worth more than the capital savings.
These are facility-level costs, not bioreactor-level costs. A single 2,000 L SUB vessel costs $200–400K, while a 10,000 L SS vessel costs $500K–$1.5M. The real cost difference is in the infrastructure required to support the vessels. Single-use dramatically simplifies the facility.
3. Operating Cost Comparison
While single-use wins on capital, stainless steel often wins on operating cost per batch—especially at high batch frequencies. The key tradeoff is consumables vs. utilities.
Single-Use Operating Costs
- Biocontainer (bag): $2,000–5,000 per 2,000 L bag
- Tubing, connectors, sensors: $1,000–3,000 per batch
- Filters (0.2 μm, depth): $1,500–4,000 per batch
- Sampling assemblies: $500–1,500 per batch
- Total consumables: $5,000–15,000 per batch
At 100 batches per year, consumables alone cost $500K–$1.5M annually. This cost scales linearly with batch number—no economies of scale.
Stainless Steel Operating Costs
- CIP chemicals (NaOH, acid, sanitizer): $200–500 per cycle
- Water for Injection (WFI): 5,000–10,000 L per CIP cycle at $0.50–$2.00/L
- Steam for SIP: $100–300 per cycle
- Labor (CIP/SIP validation, monitoring): $500–1,500 per cycle
- Total per CIP/SIP cycle: $3,000–8,000
But stainless steel also requires ongoing maintenance: gasket replacement, valve servicing, re-passivation, and periodic requalification. These add $50K–200K per vessel per year in fixed costs regardless of batch frequency.
Labor Comparison
Single-use requires fewer operators because there is no CIP/SIP to run, monitor, and validate. A typical CIP/SIP cycle takes 8–24 hours of vessel time and 2–4 hours of operator attention. With single-use, turnaround between batches can be as short as 4–8 hours (bag change, line setup, leak test). This translates to higher facility utilization and fewer FTEs.
4. The Crossover Point
The crossover point—where the total cost of ownership (capital + operating) is equal for single-use and stainless steel—depends on two primary variables: scale and batch frequency.
Scale crossover: ~2,000–5,000 L working volume
Frequency crossover: ~100–200 batches/year
Below both thresholds: single-use is cheaper
Above both thresholds: stainless steel is cheaper per batch
Mixed (small scale + high frequency, or large scale + low frequency): case-by-case
The scale crossover exists because single-use bags above 2,000 L become increasingly expensive and have engineering limitations (mixing, heat transfer, kLa). The largest commercially available SUBs are currently 4,000–6,000 L, compared to stainless steel vessels that routinely reach 25,000 L or more.
The frequency crossover exists because single-use consumables are a per-batch cost with no amortization. After enough batches, the cumulative consumables cost exceeds the capital savings. At 200+ batches per year with a 5-year facility amortization, stainless steel almost always wins on total cost.
The COVID-19 pandemic exposed a critical vulnerability of single-use: supply chain dependence. When multiple vaccine manufacturers simultaneously ramped up SU demand in 2021–2022, lead times for biocontainers extended from 4–6 weeks to 6–12 months. Stainless steel vessels, once installed, have no such supply chain risk. Factor this into your risk assessment.
5. Head-to-Head Comparison
| Factor | Single-Use | Stainless Steel |
|---|---|---|
| Capital cost | Low ($50–100M facility) | High ($200–500M facility) |
| Turnaround time | Fast (4–8h, no CIP/SIP) | Slow (8–24h CIP/SIP) |
| Contamination risk | Lower (pre-sterilized) | Higher (cleaning validation required) |
| Maximum scale | ~4,000–6,000 L | Unlimited (>25,000 L) |
| Flexibility | High (multi-product) | Low (often dedicated) |
| Environmental impact | Plastic waste (50–100 kg/batch) | Water/chemical waste (5,000–10,000 L/CIP) |
| Leachables & extractables | Concern (E&L studies required) | Not an issue |
| kLa performance | Lower (30–150 h−1) | Higher (100–400 h−1) |
| Facility build time | 18–24 months | 36–60 months |
| Supply chain risk | Higher (bag supply dependency) | Lower (once installed) |
6. Product-Specific Considerations
The optimal bioreactor technology depends heavily on what you are manufacturing. Here is guidance by product type:
Monoclonal Antibodies (High Volume)
For established commercial mAbs with annual demand >100 kg, stainless steel at >10,000 L scale is almost always the most cost-effective option. The high batch frequency and long product lifecycle (15–20 years) amortize the capital investment. However, many companies use SU for clinical supply and early commercial launch, then transition to SS as demand becomes clear.
Gene Therapy (Small Batches)
AAV and lentiviral vector manufacturing operates at small scale (200–2,000 L) with relatively few batches per year. Single-use is the dominant choice because capital efficiency matters more than consumables cost, and multi-product flexibility is essential (most gene therapy CMOs make multiple products).
Cell Therapy (Patient-Specific)
Autologous cell therapies (CAR-T) are manufactured in individual patient batches, typically in closed, single-use systems. Stainless steel is impractical for this application. Single-use is not just preferred—it is the only viable approach for patient-specific manufacturing.
Biosimilars (Cost-Driven)
Biosimilar manufacturers compete primarily on cost. For established biosimilar products with proven market demand, stainless steel at large scale provides the lowest COGS. Several large biosimilar manufacturers in Asia operate 10,000–25,000 L stainless steel facilities specifically for cost competitiveness.
Clinical Supply (Flexibility)
During clinical development, the ability to quickly switch between products in the same facility is paramount. A single-use facility can manufacture Product A on Monday and Product B on Wednesday with no cross-contamination risk. This flexibility is nearly impossible with dedicated stainless steel vessels without extensive changeover procedures.
Model Your Production Economics
Compare COGS for single-use and stainless steel scenarios with our Fermentation Economics tool.
Fermentation Economics →7. The Hybrid Approach
The most pragmatic solution for many manufacturers is a hybrid facility that combines single-use upstream with stainless steel downstream. This approach captures the benefits of both technologies where they are strongest.
Why Hybrid Works
- Upstream (bioreactors): SU bags are well-suited because each batch requires a fresh, sterile vessel. The contamination risk reduction alone justifies SU in many cases. Scale limits (2,000–4,000 L) are acceptable when multiple SUBs run in parallel.
- Downstream (chromatography): Chromatography columns and resins are inherently reusable—they are designed for hundreds of cycles. Single-use chromatography is expensive and generates massive waste. SS columns with CIP between cycles are far more economical.
- Filtration: TFF cassettes are typically single-use or limited-use regardless of the upstream technology. Depth filters and 0.2 μm filters are always single-use.
The hybrid model is increasingly the default for new mAb facilities built since 2020. It provides the fast turnaround and contamination safety of SU upstream with the cost efficiency and performance of SS downstream.
8. Environmental Perspective
The environmental debate between single-use and stainless steel is more nuanced than it first appears. Each technology generates a different type of waste:
Single-Use Waste
- Plastic waste: 50–100 kg per 2,000 L batch (bags, tubing, filters, connectors)
- Primarily polyethylene (PE), ethylene vinyl acetate (EVA), and polycarbonate
- Most SU waste is classified as biohazardous and must be incinerated, not recycled
- At 100 batches/year: 5–10 metric tons of plastic waste annually
Stainless Steel Waste
- Water: 5,000–10,000 L of WFI per CIP cycle, plus rinse water
- Chemicals: NaOH (0.5–1 M), phosphoric acid, peracetic acid
- Steam: Energy for SIP (saturated steam at 121°C for 30+ minutes)
- At 100 batches/year: 500,000–1,000,000 L of contaminated wastewater annually
Lifecycle Analysis
Published lifecycle assessments (LCAs) show mixed results. A widely cited 2012 GE Healthcare (now Cytiva) study found that single-use reduces carbon footprint by 33% and water use by 87% compared to stainless steel at the 2,000 L scale. However, critics note that these studies often exclude the environmental cost of plastic resin production and incineration, and that the comparison is not fair at larger scales where SS is more efficient.
The industry trend is toward recyclable single-use materials and take-back programs (Cytiva's Figurate, Sartorius sustainability initiatives), but these programs are still in early stages and cover only a fraction of SU waste.
If your primary concern is water and energy consumption, single-use is greener. If your primary concern is solid waste and plastic pollution, stainless steel is greener. A comprehensive environmental strategy considers both and selects the approach that minimizes total impact for your specific scale and location.
Frequently Asked Questions
What are the main differences between single-use and stainless steel bioreactors?
Single-use bioreactors use a disposable plastic bag (typically up to 2000 L) that is discarded after one batch. Stainless steel bioreactors are fixed vessels (typically 2000–20,000 L) that are cleaned (CIP) and sterilised (SIP) between batches. Key differences: single-use has lower CapEx but higher per-batch consumables cost, faster turnaround (no CIP/SIP), smaller scale ceiling (~2000 L), needs no cleaning validation, and generates plastic waste. Stainless steel has higher CapEx but lower operating cost at high throughput, reaches larger scales (up to 20,000 L), requires extensive CIP/SIP validation, and is more sustainable over long product life.
At what scale does stainless steel become cheaper than single-use?
The crossover point where stainless steel becomes cheaper than single-use is typically between 2000 and 5000 L, depending on batch frequency and facility utilisation. Below 2000 L and fewer than 20 batches per year, single-use nearly always wins on total cost. Above 5000 L with 30+ batches per year, stainless steel wins decisively. Between 2000 and 5000 L the choice depends on product flexibility needs, regulatory strategy, and CapEx availability. Higher batch frequency pushes the crossover point toward the lower end (2000 L) because consumables cost accumulates faster.
Is single-use cheaper than stainless steel?
Single-use is cheaper than stainless steel for small- to mid-scale biopharma manufacturing (<2000 L) and for facilities running fewer than 20 batches per year. Single-use saves $10–40 million in CapEx for a typical 500–2000 L facility and eliminates CIP/SIP validation. However, at large scale (>5000 L) or high batch count (>30/year), cumulative consumables cost ($20–80k per batch) exceeds the amortised cost of stainless steel. Single-use also avoids facility downtime, making it the go-to choice for multi-product CDMO operations and gene therapy.
Which is better for mAb manufacturing: single-use or stainless steel?
For monoclonal antibody (mAb) manufacturing, the choice depends on demand. Single-use (up to 2000 L) is ideal for clinical and early commercial supply up to roughly 100 kg/year of drug substance. Stainless steel (10,000–20,000 L) is the standard for blockbuster mAbs requiring >500 kg/year. Between these scales, many biopharma companies run hybrid facilities: single-use seed train and inoculum feeding a stainless steel production bioreactor. Biosimilar manufacturers increasingly favour 2000 L single-use with high-titer processes (5–10 g/L) to avoid the CapEx of stainless steel.
What are the disadvantages of single-use bioreactors?
The main disadvantages of single-use bioreactors: (1) scale ceiling at around 2000 L (3000–6000 L available from some vendors), (2) high recurring consumables cost ($20,000–80,000 per batch at 2000 L), (3) supply chain risk (bag shortages have affected multiple manufacturers), (4) extractables and leachables characterisation required for each new film/bag combination, (5) plastic waste and carbon footprint, and (6) reduced scalability compared to stainless steel vessels that can be built at 20,000 L or larger.
Are single-use bioreactors sustainable?
Single-use bioreactors have a lower water and energy footprint per batch than stainless steel because they eliminate CIP and SIP (no steam, no cleaning chemicals, no rinse water). However, they generate significant plastic waste. Recent life-cycle assessments show single-use is more sustainable than stainless steel below roughly 2000 L, particularly for campaigns shorter than 5 years. At larger scale or for long-lived products, stainless steel is more sustainable because the embodied carbon of the vessel is amortised over decades of use.
Single-use vs reusable systems: which is the right comparison for biopharmaceutical production?
The single-use vs reusable systems decision in biopharmaceutical production turns on three quantitative drivers: facility throughput, batch frequency and product life-cycle. Single-use (disposable bag) systems suit ≤2000 L scales with fewer than 20 batches per year and short campaigns, because consumables cost stays below the amortised CapEx of stainless steel. Reusable stainless steel wins above 5000 L or with 30+ batches per year, where its 20–30 year amortisation period dominates. Between 2000 and 5000 L the comparison is product-specific: gene therapy, multi-product CDMOs and biosimilars typically choose single-use; high-titer commercial mAbs choose stainless steel. Facility-fit-for-purpose modelling — not vendor preference — should drive the decision.
What is the cost crossover between single-use and stainless steel bioreactors?
The cost crossover sits at 2000–5000 L for typical CHO mAb processes at 30–50 batches per year. At 1000 L and 20 batches per year, single-use saves $15–25M in CapEx and breaks even on OpEx. At 2000 L and 30 batches per year, the two are within 10% on total cost of goods (TCOG). Above 10,000 L and 50 batches per year, stainless steel saves $30–60M over a 10-year campaign because consumables ($40–80k per batch at 2000 L scales linearly) dominate single-use TCOG. Use the bioprocess economics calculator to model your specific scale, batch frequency, titer and depreciation assumptions before committing.
References
- Langer, E.S. & Rader, R.A. (2023). "Single-Use Technologies in Biopharmaceutical Manufacturing." BioPlan Associates Annual Report and Survey of Biopharmaceutical Manufacturing Capacity and Production, 20th Edition.
- Sinclair, A. & Monge, M. (2010). "Quantitative Economic Evaluation of Single Use Disposables in Bioprocessing." Pharmaceutical Engineering, 30(3), 1–8.
- Rawlings, B. & Pora, H. (2009). "Environmental impact of single-use and reusable bioprocess systems." BioProcess International, 7(2), 18–25.
- Pietrzykowski, M., Flanagan, W., Pizzi, V., et al. (2013). "An Environmental Life Cycle Assessment Comparison of Single-Use and Conventional Process Technology for the Production of Monoclonal Antibodies." Journal of Cleaner Production, 41, 150–162.