Foreign Matter and Admixture Limits for Whole Spices

What is foreign matter in whole spices?

Foreign matter is any material in a spice lot that is not the spice itself, including stems, stones, dust, husk, insect fragments and other plant debris. Grading standards split this further into two categories: extraneous matter (mineral items such as sand, stone, metal or glass) and organic foreign matter (other plant material, stems, seed coats of a different crop). A typical export-grade whole spice carries a combined foreign matter limit between 0.5% and 2% by weight, depending on the spice and the destination market's tolerance.

Buyers who only read "foreign matter: 1% max" on a certificate are missing half the picture. The breakdown between extraneous (mineral) and organic foreign matter matters more than the total, because mineral content is the flag regulators and mills care about most, particularly for metal detection and X-ray screening downstream.

What is admixture and how is it different from foreign matter?

Admixture means a different, similar-looking seed or spice mixed into the lot, either accidentally during harvest or deliberately to add weight or bulk a shortage. This is distinct from foreign matter because admixture is still an agricultural seed, just not the one declared, so a basic sieve or visual sort will not always catch it. Classic admixture pairs include papaya seed in black pepper, charged (dyed) seed mixed into coriander, and grass seed in cumin lots.

An experienced buyer asks the supplier specifically for an "admixture" figure separate from "foreign matter" on the quality certificate, because a supplier can legitimately report 0.5% foreign matter while 3% of the lot is a cheaper substitute seed that was never flagged as foreign matter at all, since it is organic material of spice origin.

What are typical limits by spice type?

Limits vary by grade, season and the standard applied (ISO, ASTA, or a buyer's own house specification), but the ranges below reflect common export-grade targets.

Spice	Foreign Matter (max)	Extraneous Matter (max)	Common Admixture Risk
Coriander seeds (/products/pulses-lentils/coriander-seeds-dhaniya)	1.0% to 1.5%	0.5%	Crushed stalk, immature green seed
Ajwain / carom seeds (/products/spices-masalas/ajwain-carom-omam-seeds)	1.0%	0.5%	Lovage seed, dusty chaff
Anardana / dried pomegranate seed (/products/spices-masalas/anardana-dried-pomegranate-seeds)	1.0% to 2.0%	0.5%	Pulp fragments, stem bits
Dry mango slices (/products/spices-masalas/amchur-whole-slices-dry-mango-slices)	1.0%	0.5%	Peel fragments, stone chips
Whole dried chilli	1.0%	0.5%	Stem content above spec, broken calyx

These figures are typical, not guaranteed; the confirmed limit for any order is stated on the quotation and the accompanying certificate of analysis. Tighter limits, down to 0.25% to 0.5%, are available at a premium for food manufacturing grades where the spice goes straight into grinding without a manual sort step.

How is foreign matter actually tested?

It is tested by manual sorting of a weighed sample against a reference chart, followed by a sieve pass for fine dust and mineral particles. A standard method, close to ISO 927, takes a representative sample (typically 100 g to 500 g depending on lot size), spreads it on a sorting tray, and separates it by hand into spice, organic foreign matter, extraneous matter and admixture, with each fraction weighed on a precision scale and reported as a percentage.

What a generic buyer's guide will not tell you is that sample size matters more than most import contracts specify. A 100 g sample pulled from the top of a bag will consistently underreport foreign matter compared to a composite sample drawn from multiple depths and multiple bags in the lot. When requesting a certificate, ask whether the sample was composite or spot, and from how many bags or totes it was drawn.

What does an experienced sourcing manager check beyond the certificate?

They check the mesh size and sieve specification used, not just the percentage, because a 1% foreign matter result on a 10-mesh sieve hides far more fine dust than the same result on a 20-mesh sieve. They also ask for a photo of the uncleaned sample before any rework, because some facilities clean a sample lot separately from the bulk shipment lot.

A second practical check is asking whether the lot passed through optical sorting, gravity separation or only manual winnowing. Optical sorters catch discoloured seeds and some insect damage that manual winnowing misses, and gravity tables separate stones and dense admixture by density rather than size, which is the only reliable way to remove stone from a seed spice of a similar size.

What does US customs and FDA actually check on arrival?

US FDA applies defect action levels (DALs) that cover insect filth, rodent filth and mould in addition to the inert foreign matter percentage used in trade grading. These are enforced independently of the commercial grade stated on the invoice, meaning a lot can meet a 1% foreign matter commercial specification and still be detained if insect fragment counts exceed the DAL for that spice category. This is a separate check from pesticide residue or Ethylene Oxide testing and is based on physical and microscopic examination of the sample pulled at the port or warehouse.

Importers should keep the certificate of analysis, the phytosanitary certificate and the packing list aligned on lot numbers, since FDA sampling ties back to a specific lot, and a mismatch between documents and physical lot marking is one of the more common causes of delayed release that has nothing to do with the spice quality itself.

How should a buyer write foreign matter limits into a purchase contract?

A buyer should state the maximum foreign matter percentage, the maximum extraneous matter percentage, and a separate admixture tolerance, each tied to a named test method and sample size. Leaving the specification as a single combined number gives the supplier room to meet the total by under-declaring admixture as spice-origin material, which technically is not foreign matter but still dilutes the active content a manufacturer is paying for.

For food manufacturing buyers in particular, it is worth specifying the limit separately for whole form versus any rework or reprocessed fraction blended back into the lot, since reworked material tends to carry a higher foreign matter load than first-pass cleaned spice.

ODOD provides a certificate of analysis with every quotation, covering foreign matter, extraneous matter and moisture, along with US FDA registration, ISO, Halal, HACCP and GMP documentation. Specifications, available grades and packing options are confirmed on request; to discuss limits for a specific spice and volume, request a quotation at /enquiry.