Food Grade vs Technical Grade: What the Documentation Has to Say

Citric acid is citric acid. Except that the drum a beverage plant can accept and the drum a descaling formulator can accept are not interchangeable, and the difference is not visible in the material.

Grade is the part of a specification most often left off an enquiry, and it is the part most likely to make a delivery unusable.

What actually separates the grades

Technical / industrial grade is manufactured to a purity that suits a process, with impurities controlled only to the extent that they affect that process. It is the right choice for the large majority of industrial duty and the wrong one for anything with human contact.

Food grade is manufactured and handled to a food safety standard, and carries a monograph — typically FCC (Food Chemicals Codex). The controlled parameters are different from technical grade, not merely tighter: heavy metals, arsenic, lead and microbiological limits are specified because those are what matter when a person eats the result.

Pharmaceutical grade works to a pharmacopoeia monograph — BP, USP or EP. On top of the purity specification comes documented manufacturing control, batch traceability and an impurity profile the monograph names individually.

Analytical reagent (AR) grade is for laboratory use, where the point is that the reagent does not contribute anything to the measurement. Purity is highest here, but AR grade is not a substitute for food grade: it is manufactured for analytical reliability, not for food safety, and it is not handled under a food regime.

Cosmetic grade sits against its own standards for skin contact and for the impurities that matter there.

The purity number is not the grade

This is the trap. A technical grade at 99.5% and a food grade at 99.0% look as though the technical material is "better". It is not — for food duty it is unusable.

The percentage tells you how much of the container is the named substance. The grade tells you what the other fraction is allowed to be, and under what regime it was made and handled. A technical grade with 0.5% unspecified impurities is fine in a cooling tower and inadmissible in a soft drink.

Buy against the monograph, not against the headline number.

What the documentation must show

For a food or pharmaceutical grade, the certificate of analysis is the control, and it has to state:

• The monograph the batch was tested against — "FCC", "BP 2020", "USP-NF",

not the word "food grade" alone

• The batch or lot number, matching the container
• Actual measured results, not just the specification limits
• Heavy metals, arsenic and lead where the monograph requires them
• Manufacture and expiry or retest dates
• Manufacturer identification

A COA that states limits without results is not a certificate of analysis. A document that says "food grade" with no monograph named is a marketing claim.

Where the material is for food contact, you may also need a manufacturer's declaration of food-grade status and, for export, whatever attestation the destination requires.

Say it on the enquiry

Most grade mix-ups are not supply failures. They are enquiries that named a chemical and a quantity and left the grade to be inferred.

State on the enquiry:

1. 1.The chemical name, and the CAS number if you have it
2. 2.The grade and monograph — "citric acid anhydrous, FCC" rather than

"citric acid, food"

1. 1.The end use, which lets a supplier catch a mismatch you have not spotted
2. 2.Concentration or assay where the product is supplied at more than one
3. 3.Pack size, and whether packaging itself has a food-contact requirement
4. 4.Any documentation your QA, auditor or customs clearance needs
5. 5.Destination, where import documentation is involved

The CAS number is worth including whenever you know it. Trade names vary between suppliers and countries; the CAS number does not, and it removes an entire class of ambiguity in one field.

When a substitution is offered

Sometimes the exact grade is not available and an alternative is proposed. That can be entirely legitimate — a higher monograph grade generally satisfies a lower requirement.

The direction is what matters. Pharmaceutical grade will usually serve a food duty. Technical grade never serves a food duty, whatever its assay. If a substitution is offered in that direction, the answer is no, and a supplier worth using will have said so first.

Get any substitution confirmed in writing, with the COA for what is actually being shipped.

In short

Name the grade, name the monograph, and check the COA against both on arrival. The material cannot be inspected for compliance — the paperwork is the only place the difference is visible.

Browse the chemical catalogue with grades and CAS numbers listed, or request a quotation stating the grade you need.