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The analysis of mineral oil hydrocarbons (MOH), and particularly mineral oil aromatic hydrocarbons (MOAH), is widely recognised as one of the more complex challenges in food analysis. This is especially true for herbs and spices. 

Why herbs and spices are so challenging

Herbs and spices are analytically complex matrices by nature. A key reason is their intrinsic composition.

Like all plant-based materials, they naturally contain a wide range of so-called biogenic hydrocarbons. These compounds originate primarily from natural wax layers that protect leaves, seeds, and other plant surfaces against dehydration and environmental stress.

These natural compounds: 

• are intrinsic to the plant matrix
• have chemical structures very similar to MOSH and MOAH
• can co-elute during LC-GC-FID analysis  

As a result, distinguishing between naturally occurring hydrocarbons and potential contamination is delicate and requires careful analytical consideration, particularly at low concentration levels. 

(Want to know more about MOH and their background, read our paper here)

Low limits, high complexity 

Regulatory expectations for MOAH have largely been shaped by the JRC guidance document, which defines achievable limits of quantification (LOQs) for different food categories.  

Based on this approach, EU Member States have issued a common position, introducing three indicative categories:  

• 0.5 mg/kg for dry foods with a low fat/oil content (≤ 4% fat/oil)
• 1 mg/kg for foods with a higher fat/oil content (> 4% fat/oil)
• 2 mg/kg for fats/ oils  

Herbs and spices, given their composition, fall into the low-fat category (<4%), corresponding to the lowest indicative limit.  In practice, many Member States already apply these levels.  
  
This is where complexity arises. The combination of a naturally complex matrix - rich in interfering hydrocarbons - and very low target levels makes MOAH analysis in herbs and spices particularly demanding. Not only form an analytical perspective, but also in terms of data interpretation and decision-making. 

Reflected in EU legislation  

This challenge is also recognised at European level.  

In the draft proposal to include MOAH limits in Regulation (EU) 2023/915, the European Commission introduces a specific category for herbs and spices with a proposed limit of 5 mg/kg. 

This limit is notably higher than the levels currently applied in practice based on the JRC-derived approach.  

It can be seen as an acknowledgement of the analytical complexity of these matrices and of the need to ensure that limits remain robust and practically applicable. 

On 11 March 2026, a revised draft of this proposal provided further insight into the expected regulatory timeline. Entry into force is currently foreseen for September 2026, with application from 1 January 2027, alongside a gradual refinement for certain product categories in the years thereafter. 

Bridging limits and reality

Herbs and spices highlight a delicate balance within MOAH analysis.  

On the one hand, low limits remain essential from a food safety perspective.  On the other hand, complex matrices can make these limits challenging to interpret in practice. 

Bringing both aspects together — protective thresholds and analytical reality — is key to making results meaningful and supporting well-informed decisions across the food chain.