Hi Folks,
I hope you can help me with my query :)
I requested allergen swab analyses in terms of nuts (cashew), celery and milk from manufacturing site as customer site is completely nut free. Lab analyses result are <5mg/pad for cashew; <5mg/pad for albumin; <10mg/pad for celery (everything tested by PCR). Can you please advise whether those results are low and there is no harm for potential allergy sufferers?
I can't find straightforward answer online in terms of limits and never dealt before with allergen swabs. i am based in UK.
Thank you very much for your help.
Hi Irulan,
afaik there is no defined official UK tolerance for the allergens mentioned. The nominal tolerance is zero.
The reason is that, for the allergens mentioned, the lowest "safe" level (if it exists) is undefined/unknown/disagreed.
Allergen "ranking" systems (including "thresholds") are extensively discussed in the literature but afaik only one such system (VITAL) has been officially implemented for labelling purposes in a few locations, eg Australia. Not used in UK afaik.
Yr query has labelling and cleaning connotations as noted in previous post. Labelling is a bit of a minefield from allergen POV.
I anticipate that the "<" signs in yr OP indicate nil detection at some undefined instrument sensitivity.
If interested, you could maybe compare the data with VITAL tables if you can transform the "mg/pad" to units like ppm (~mg/litre). I daresay this calculation relates to the sampling/analysis procedure as per kit manufacturer's instructions. A question for the lab. 
I expect an officially declared status such as "nut-free" (if it exists) will have a set of (somewhere) defined official compliance requirements. (No idea UK)