Flavour and fragrance manufacturing runs an unusual commercial model through a chemical plant: very high SKU counts, very small batches, very high value per kilogram, and extreme sensitivity to cross-contamination. A trace carryover that would be irrelevant almost anywhere else can render a batch worthless. That, combined with substantial ethanol and solvent inventory, defines the engineering problem.

Projex Solutions provides engineering design, process safety studies and project delivery for flavour, fragrance and aroma chemical manufacturers, covering compounding, extraction, distillation and blending.

What makes this work different

Cross-contamination tolerance is extraordinarily low. Cleaning validation, dedicated equipment, line design and dead-leg elimination matter more here than the batch size would suggest. Plant designed for chemical duty rather than for cleanability will not perform.

Ethanol and solvent inventory drives DSEAR and COMAH. Alcohol-based compounding holds significant flammable inventory, requiring hazardous area classification to BS EN IEC 60079-10-1:2021 and EI 15 (5th edition), and frequently bringing COMAH duties.

Odour is a regulatory issue, not a nuisance. Aroma chemicals are detectable at extremely low concentrations, so odour management, abatement and dispersion form part of the environmental permit and often of the site’s relationship with its neighbours. Complaints can constrain operations more effectively than emission limits.

VOC emissions are permitted. Solvent use and extraction operations fall under the Environmental Permitting (England and Wales) Regulations 2016 (as amended), with abatement performance forming part of the permit.

Small batch, high changeover. Hundreds or thousands of SKUs through limited plant means changeover is the dominant throughput constraint.

IFRA standards govern ingredients. Restrictions are revised regularly. We design plant with the flexibility to accommodate reformulation rather than assuming a fixed ingredient list.

Where we help

  • DSEAR assessment and hazardous area classification for ethanol and solvent service
  • COMAH tier determination and safety report engineering support
  • Cleanability-led plant design, covering dead-leg elimination, drainability and cleaning validation support
  • Changeover reduction design for high SKU count operations
  • Odour and VOC abatement design, with dispersion assessment and permit support
  • Extraction and distillation plant design
  • HAZOP facilitation, LOPA and SIL determination to BS EN 61511
  • Feasibility, FEED, detailed design and EPCM delivery under ISO 9001:2015

Typical reasons clients get in touch

  • Cross-contamination is limiting which products can run on which plant
  • Odour complaints or permit conditions are constraining operations
  • Ethanol inventory has grown and COMAH status needs establishing
  • Changeover time is the binding constraint on throughput
  • Area classification predates the current standards
  • Extraction or distillation capacity needs increasing

Related

Part of our work across the FMCG sector and the chemical sector. See also personal care and cosmetics manufacturing.

Standards and regulations we work to

  • DSEAR 2002, with ACOP L138 (second edition, 2013)
  • BS EN IEC 60079-10-1:2021 and EI 15 (5th edition, October 2024)
  • COMAH 2015, where ethanol and solvent inventory crosses threshold
  • Environmental Permitting (England and Wales) Regulations 2016 (as amended), for VOC emissions and odour
  • COSHH 2002, with ACOP L5 (sixth edition, 2013)
  • IFRA Standards, worked to the amendment current at time of design
  • PSSR 2000, with guidance L122 (2014)
  • CDM 2015 and ISO 9001:2015

Frequently asked questions

Why does odour matter more than emission limits?
Because aroma chemicals are detectable at concentrations far below any limit that would trouble a permit. A site can be comfortably compliant and still generate complaints, and sustained complaints constrain operations more effectively than a numerical limit does. Dispersion and abatement need designing with that in mind.

Our cross-contamination tolerance is extremely low. Does plant design really help?
It is most of the answer. Dead legs, poor drainability, shared lines and hard-to-clean fittings are what carry residue between batches. Plant designed for chemical duty rather than for cleanability will always struggle, however good the cleaning procedure.

We run hundreds of SKUs in small batches. What limits throughput?
Changeover, almost always. The productive answer is usually a mix of dedicated equipment for the most persistent materials, cleaning design that shortens validated cycles, and better sequencing.

Do we need a full area classification for a small compounding operation?
If you hold and transfer ethanol or solvents, yes. Scale reduces consequence but does not remove the duty, and small operations are frequently the ones with no classification at all.

Can odour abatement be added to an existing plant?
Usually, though the right answer depends on the source. Capture at source is almost always more effective and cheaper to run than treating a large diluted volume, so we would look at containment before abatement capacity.

How do you handle very small batch sizes?
By designing for cleanability and changeover rather than for throughput. On high-SKU, small-batch plant the productive capacity is determined by how quickly a vessel can be turned round, not by how much it holds.

Can extraction or distillation capacity be increased without a new building?
Often. Column internals, condenser duty and vacuum capability frequently limit throughput before vessel volume does, and addressing those is considerably cheaper than extending the plant.

Talk to us about your plant. Request a call