What containment requirements apply to API manufacturing in the pharmaceutical industry?
Short answer: API manufacturing faces two sets of containment requirements. First, operator protection: exposure must stay below the occupational exposure limit (OEL), as required by national workplace law and EU Directive 2004/37/EC on carcinogens, mutagens and reprotoxic substances. Second, product protection: EU GMP (Chapters 3 and 5, Part II/ICH Q7) requires cross-contamination control based on health-based exposure limits (HBEL/PDE). Technology is selected through OEB classes and proven with measurements according to ISPE SMEPAC.
Active pharmaceutical ingredients (APIs) keep getting more potent. Oncology drugs, hormones and ADC payloads act at microgram levels. That raises the bar for containment at every process step. Hecht Technology, specialist in containment and powder handling for pharma (OEB 1–6), explains which requirements apply and how to meet them in practice.
Read also: Which suppliers offer high containment systems for powder processing?
Two goals: protect the operator and the product
Pharmaceutical containment serves two interests that reinforce each other.
- Operator protection: employees must not be exposed above the OEL. This is occupational safety law.
- Product protection: no cross-contamination between products or batches. This is GMP law.
A sound containment concept covers both. An isolator protects the operator; a closed transfer prevents residues from ending up in the next product.
The regulatory framework for API containment
EU GMP and HBEL
Since the revision of EU GMP Chapters 3 and 5, manufacturers must control cross-contamination based on Health-Based Exposure Limits (HBEL). The EMA guideline on setting PDE values (Permitted Daily Exposure) is the reference. APIs are additionally covered by EU GMP Part II (ICH Q7). Risk management follows ICH Q9(R1).
Occupational safety law
EU member states require employers to prevent or minimise exposure to hazardous substances. In the Netherlands this is the Arbobesluit. For carcinogenic, mutagenic and reprotoxic substances, Directive 2004/37/EC applies, explicitly including reprotoxic substances since 2022. The hierarchy of controls requires engineering measures before personal protective equipment.
Industry standards
- ISPE Risk-MaPP: risk-based approach for multi-product facilities.
- ISPE SMEPAC: standardised method to measure the containment performance of equipment.
From OEB class to technical solution
A substance's OEL determines its OEB class. The class drives the technical choice. Indicative:
| OEB | OEL (µg/m³) | Typical solution |
|---|---|---|
| 1–2 | > 100 | Local exhaust ventilation, closed containers |
| 3 | 10–100 | Extraction hoods, closed transfer, basic split valves |
| 4 | 1–10 | Split valves, closed big bag systems, flexible isolators |
| 5 | 0.1–1 | Stainless steel or single-use isolators, contained filling heads |
| 6 | < 0.1 | Fully closed isolator technology, negative pressure, single-use |
Note: OEB bands differ between companies. Always use your own toxicological assessment.
Which process steps need containment?
In API manufacturing, risks concentrate at open transfer points:
- Raw material receipt and sampling (CPS sampling)
- Weighing and dispensing (EPS isolators)
- Charging reactors and dryers (split valves, vacuum conveying)
- Discharging centrifuges and filter dryers
- Filling the final product (LBK filling heads, endless liner)
Every transition counts. One open step makes the whole chain as weak as that step.
How to demonstrate containment
A design on paper is not enough. Inspectors and occupational hygienists want data.
- Surrogate testing with, for example, lactose or naproxen sodium, according to ISPE SMEPAC.
- Air sampling in the breathing zone during normal and abnormal operations.
- Surface wipe tests for cleaning verification.
- Periodic reassessment after changes to product or process.
How Hecht Technology supports you
Hecht Technology B.V. (Delft) supplies the HECHT portfolio for containment up to OEB 6. From EPS and EWI single-use isolators to LBK filling heads, big bag systems and vacuum conveying. At the HECHT Test & Trial Centre we test with your product or a surrogate. That way you support your risk assessment with real data.
Frequently asked questions
What is the difference between OEL and PDE?
The OEL protects the operator (µg/m³ of air). The PDE protects the patient (mg per day) and sets the acceptance limit for cross-contamination.
Is a dedicated facility mandatory for potent APIs?
Not automatically. EU GMP allows shared facilities if you demonstrate, based on HBEL, that risks are controlled.
Can I rely on PPE instead of engineering controls?
Only as a supplement. The hierarchy of controls requires source measures first.
Conclusion
Containment in API manufacturing is not optional. It is a legal obligation under both occupational safety and GMP law. Start with toxicological data, translate it into OEB classes and choose technology you can validate.
TL;DR: API containment protects the operator (OEL, Directive 2004/37/EC) and the product (EU GMP, HBEL/PDE, ICH Q7). The OEB class drives technology: from extraction at OEB 1–2 to isolators at OEB 5–6. Prove performance with ISPE SMEPAC measurements. Hecht Technology supplies and tests containment solutions up to OEB 6.
Want your containment strategy reviewed? Contact us via hecht-technology.nl or visit hecht.eu.
Last updated: September 2026