T-03
Contaminants and residues
Heavy metals, mycotoxins, pesticide and veterinary residues and process contaminants, measured against the limit that actually applies to your commodity.
- What it is
- Metals, mycotoxins, residues, process contaminants
- Who it is for
- Importers, exporters and high-risk commodity handlers
- Turnaround
- Up to 14 days
WHAT THIS IS
What this is, and why it matters
Contaminant testing measures substances that should not be present, or should only be present below a stated limit. Four families cover most of the work. Heavy metals — lead, cadmium, mercury, arsenic, tin — arrive from soil, water, packaging or processing equipment. Mycotoxins — aflatoxins, ochratoxin A, deoxynivalenol — are produced by moulds on cereals, nuts, spices, dried fruit and feed. Pesticide and veterinary drug residues carry over from agricultural use. Process contaminants such as acrylamide and histamine are created by the process itself, or by mishandling before it.
This is the testing that carries the highest regulatory consequence in this market. A contaminant exceedance is not a quality problem to be negotiated with a customer — it is a held consignment, a withdrawal, or an enforcement action. It is also the area where a result means nothing without its limit: the same lead value can be compliant in one commodity and an exceedance in another. Every report here states the limit applied and the source of that limit alongside the result, because a number on its own is not a decision.
What this lane covers
- Heavy metals, mycotoxins, pesticide and drug residues
- Reported against the specific regulatory or customer limit
TRIGGERS
When you need it
You import or you export
Consignments are cleared against contaminant limits, and a certificate of analysis is routinely part of the documentation. Testing before the consignment moves costs less than testing after it has been held.
Your commodity carries a known risk
Nuts, cereals, spices, dried fruit, rice, fish and animal feed each carry a characteristic contaminant risk. A real supplier approval programme tests that risk on incoming lots rather than filing the certificate the supplier sent with them.
A regulator or a customer has asked
SFDA sampling, a customer audit finding, or a withdrawal elsewhere in your category all generate the same request: current data on your own product, not on a comparable one.
CATALOGUE
Contaminants — parameters
Total aflatoxin
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Aflatoxin B1, B2, G1 and G2
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Aflatoxin M1
- Matrix
- Dairy products
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Ochratoxin
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Trace elements (Pb, Hg, Cd, As)
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Pesticide residues
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Antibiotic residues
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Colours in food
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Sweeteners and caffeine (acesulfame-K, saccharin, aspartame)
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Dioxins
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Furan and methylfurans
- Matrix
- Food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Hydroxymethylfurfural (HMF)
- Matrix
- Food, honey
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Acrylamide
- Matrix
- Fried and baked food
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Histamine
- Matrix
- Fish and fishery products
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Deoxynivalenol (DON)
- Matrix
- Cereals, feed
- Reference method
- Per partner laboratory method
- Run by
- Partner laboratory
- Turnaround
- Up to 14 days
Published from the laboratory’s own method list. Reference methods shown are the primary reference for each determination; the full reference set, sample requirement and confirmed turnaround are issued in writing before any sample is accepted.
Lines marked “partner laboratory” are managed and reported by Nexus Labs and run on a partner laboratory’s bench. Which laboratory, and its accreditation position, is named on request before the work is commissioned.
PROCESS
How it works
Send the brief before the sample
The commodity, the contaminants in question, and the limit you are being held to — a regulatory limit, a customer specification, or a destination market requirement. Contaminant work is defined by its limit, so this is the first thing the laboratory needs.
Sample requirements confirmed in writing
Contaminant sampling is where representativeness matters most, because contamination is rarely evenly distributed through a lot — aflatoxin in a nut consignment being the standard example. Sample size, the number of incremental samples and how they are combined are confirmed in writing before you sample.
On the bench, to a published method
Every determination runs to the ISO, AOAC or APHA method named in the catalogue above, and that reference travels onto the report line rather than sitting in a footnote. Turnaround runs from acceptance at the laboratory, not from the day the sample left you.
Reported so the result can be acted on
The report states the result, the limit applied, and the source of that limit, so the compliance position is on the page. Results near a limit are reported with their measurement uncertainty, because that is the point at which uncertainty changes the decision.
What you get back
A report stating each contaminant, the method, the measured value, the limit applied and where that limit comes from — the form a customs broker, a customer or an SFDA reviewer expects to receive it in.
Service facts
| Parameter | Value | Note |
|---|---|---|
| Accreditation position | Not on the accredited scope, and not run on this bench. Every determination on this page is placed with a partner laboratory under Nexus management. The partner and its own accreditation position are named in writing before the work is commissioned. | Stated per discipline, never implied by a badge. |
| Sample requirements | Confirmed to you in writing before dispatch. Container, quantity, temperature and hold time change with the parameter and the matrix, so they are issued per request rather than published as one list. | Per-parameter detail publishes with the confirmed method list. |
Q+A
Common questions
Contaminants
My customer asked for a “heavy metals test” — which metals do they mean?
There is no single heavy-metals test — the list depends on the product. The applicable limits for contaminants and toxins in food sit under SFDA.FD CAC 193, and the laboratory confirms in writing which metals and which limits apply to your product before testing starts.
Is GSO 2481 the heavy-metals standard?
No — GSO 2481 covers maximum residue limits for veterinary drugs. Heavy metals and other contaminants in food are judged against SFDA.FD CAC 193. The report states which limit each result was compared to, and its source.
Do you report pass/fail or just numbers?
Each result is reported with the limit it was judged against and where that limit comes from. A result without its limit cannot be acted on; with the limit and its source, it becomes a decision you can defend to a customer or an inspector.
Can one sample cover metals, mycotoxins and pesticide residues?
Often, but the quantity needed depends on the panel. The laboratory confirms the required amount in writing before you sample, so you are not asked for more material after the batch has shipped.
A customer rejected a batch for a residue — can you retest it?
Yes, if retained sample from that batch exists — testing a different batch answers a different question. The report states exactly what was tested and against which limit, which is what the customer’s QA team will ask for first.
Send the sample question or the instrument list. It is read by a bench professional, not routed through a ticket queue. Call +966 59 637 8052 or write to lab-mgr@qsinexus.com.
CONTINUE
Where to next
Sending a sample
Packing, labelling, temperature and what has to travel with the sample so it arrives usable.
ReadImporting food into Saudi Arabia
Where contaminant testing sits in the border chain, and why testing before the goods move is cheaper.
ReadForms and documents
Submission form, chain of custody and the calibration request, ready to fill in first.
Read