How to choose a toll manufacturer
For the first shortlist, and for the visit that decides it. The questions are the ones our broker desk puts to a unit before an enquiry goes any further.
Updated
Start from the process, not from the company
The most common way to pick badly is to start from a list of well-known names and ask which of them could run your product. That question invites a yes. Starting from the process and asking who already has the equipment, the approvals and the handling experience produces a shorter list and a truer one.
Write the requirement as the plant will have to read it: unit operations in sequence, batch size, materials of construction the chemistry demands, temperature and pressure range, utilities, hazard classes, and the certifications your customer or your regulator requires. A requirement written this way can be matched against a vessel list. A requirement written as a product name cannot.
Be specific about volume and frequency early, even approximately. A plant scheduling a reactor wants to know whether this is one campaign or twelve a year, and the answer changes both the price and whether they want the work at all.
The documents that decide it
Capability claims are cheap. Documents are not, and four of them settle most questions before anyone travels.
- Consent to operate, issued by the state pollution control board, valid on the dates your campaign will run, and naming the process and the hazard categories you need. A consent that does not cover your chemistry is the single most common reason a promising plant cannot actually take the work.
- Factory licence, current, with the sanctioned worker strength and the activities it permits.
- GST registration, which also tells you the legal entity you will be contracting with rather than the trading name on the letterhead.
- Certifications such as ISO 9001, ISO 14001 or GMP, with expiry dates. Ask for the certificate, check the scope on it, and note that scope frequently covers only part of a site.
Capability is not capacity
A plant can own exactly the right reactor and still be the wrong answer, because that reactor is committed for the next seven months. Capability tells you whether the process can run there. Capacity tells you whether it can run there when you need it. Both have to be confirmed, and only one of them is usually volunteered.
Ask for the vessel or line list by material of construction and working volume, with the utilities attached to each: chilled brine, hot oil or steam, vacuum, nitrogen, and the scrubber serving that bay. Then ask which of those are free in your window, and what would have to move if they are not.
Working volume is the number that matters, not nominal vessel size. A five kilolitre reactor is not a five kilolitre batch: headroom for agitation, foaming and exotherm control is not optional, and a plant that quotes nominal capacity as batch size is telling you something about how it operates.
Quality systems, and how to test them cheaply
You are buying repeatability more than you are buying equipment. The cheapest test of it is a trial batch run on the plant’s own line, with the sampling plan agreed in advance and a retained sample kept.
Around that, ask how they release a batch. Which method, against which limits, on whose instrument, calibrated when, and who signs. A plant that sends everything to an outside laboratory is not disqualified, but the turnaround becomes part of your cycle time and should be priced as such.
Ask to see a batch record from a comparable product with the customer details removed. A real record shows charge weights, timings, deviations and signatures. What it looks like tells you more about a site than any certificate on the wall.
The site visit
Visit before the first production campaign, not after the first problem. An hour on site answers questions that months of correspondence will not, and most of what you are looking for is visible without asking.
- Housekeeping in the production bays and the warehouse. It correlates with batch discipline more reliably than any document.
- Segregation and labelling of incoming material, and whether your drums would be stored apart from everyone else’s.
- The effluent route: where it goes, whether the plant is connected to the common treatment scheme, and what its consented load is against what your campaign will add.
- Whether the people who will actually run your batch are present and can describe the process, as distinct from the manager escorting you.
- Spare parts, standby utilities and what happens on a power failure mid-batch, which in an Indian chemical estate is a question about your product, not about their inconvenience.
Commercial terms worth settling before the first batch
Most disputes in toll manufacturing are not technical. They are about something both sides assumed and neither wrote down.
- Yield: the assumed figure, who carries the loss below it, and what happens to material that fails specification.
- Cycle time: the hours assumed per batch, since most of a toll price is rent on the asset for as long as your product occupies it.
- Recovered solvent and saleable by-products: who owns them, at what assumed recovery, and who pays for residue disposal.
- Exclusions: effluent treatment, hazardous waste, packing material and analysis are the usual omissions from a quotation.
- Confidentiality and non-circumvention, signed before your specification and material safety data sheets are released rather than after.
Red flags
None of these is proof of a bad plant. Each is a reason to slow down and verify before material moves.
- A consent to operate that does not name your process, offered with an assurance that it will be amended later.
- Reluctance to allow a visit, or a visit confined to the office and the boardroom.
- A quotation with no cycle time and no yield assumption in it.
- An unwillingness to run a trial batch, or pressure to skip straight to production volume.
- Certificates whose scope, on reading, covers a different part of the site or a different activity.
- A price far below the others with no explanation of where the saving comes from. In this industry the usual answer is effluent.
Common questions
- What should I check before sending material to a toll manufacturer?
- A consent to operate that names your process and is valid on your campaign dates, the factory licence, GST registration, and any certifications with their scope and expiry. Then the vessel list by material of construction and working volume, the effluent and hazardous waste route with manifests, and a trial batch on the plant’s own equipment before a production order.
- What is the most common reason a good plant cannot take my work?
- Its consent to operate does not cover your process or hazard category. The equipment is right, the people are capable, and the statutory permission is for something else. This is why the consent is the first document to ask for rather than the last, particularly in estates where a change in product mix is itself a regulated event.
- Should I visit the plant before placing a toll manufacturing order?
- Yes, before the first production campaign rather than after the first problem. Housekeeping, material segregation, the effluent route and whether the operators can describe your process are all visible in an hour on site and invisible in correspondence. Ask to see the production bay, not only the office.
- How do I compare toll manufacturing quotations fairly?
- Fix the yield assumption and the cycle time for every quotation before you look at the totals, and ask each plant what is excluded. Effluent treatment, hazardous waste, packing and analysis are the usual omissions, and ownership of recovered solvent can be worth more than the gap between two prices.
- What batch size can a toll manufacturer actually run?
- Ask for working volume rather than nominal vessel size. A reactor needs headroom for agitation, foaming and exotherm control, so the usable batch is meaningfully smaller than the plate figure. A plant that quotes nominal capacity as batch size is telling you something about how carefully it operates.