Frequently Asked Questions Registration under REACh of 'Mixed Fatty Acid'

Due to the large number of enquiries a ‘FAQ catalogue’ was compiled to provide answers to all questions which arose in connection with the intended REACh registration of ‘Mixed Fatty Acid’.

The following explanations were made to be best of the current knowledge of the legal situation. However, it cannot be ruled out that individual circumstances may be interpreted differently, especially by enforcement authorities. In case legal stipulations other than those for REACh are concerned (e.g. waste legislation) reference is made to the German regulations. The legal definition in other European countries may differ gradually/partially.

What is ‚Mixed Fatty Acid‘?

'Mixed Fatty Acid’ is the abbreviated designation for the substance which is automatically generated immediately after transesterification as by-product of the Biodiesel production process. Dependent on the production process, it consists of differing quantities of free fatty acid, fatty acid methyl ester and methanol. In addition, other contaminants such as Alkali hydroxides or Alkali salts may also be contained.

Does Fatty Acid generated as by-product of oil mill refining also come under the term ‘Mixed Fatty Acid‘? 

No. Its origin, production process and composition are entirely different. That substance usually fulfills the requirements according to Annex IV/V of the REACh regulations necessary for exemption from the obligation to register.

Why is ‚Mixed Fatty Acid‘ liable for registration under REACh?

Under certain additional conditions fatty acids as pure substance are exempted from the obligation to register under REACh; however, ‘mixed fatty acid’ is no pure substance but a mixture consisting of various constituents and resulting from a chemical reaction. Therefore, exemption from the obligation to register is not applicable. In addition, the presence of methanol (and other constituents) may cause special risk features.

If ‘mixed fatty acid’ is treated and handled as waste there is no obligation to register it under REACh. However, all requirements according to waste legislation must be abided by such as handing over the substance to a waste management company accredited for the proper waste code number; furthermore all monitoring and registration duties must be fulfilled. Free marketing as merchandise in not permissible in that case.

If necessary, the company is responsible to provide for the registration required.

Can ‘mixed fatty acid’ be considered a ‘composition’?

Principally, a mixture of the aforementioned substances may also be considered a composition (which would only require the individual substances to be handled according to REACh). However, a composition is the intentional mixture of different substances according to a defined recipe without inducing any chemical transformations among the mixed substances. In the case presented it should be difficult to constitute ‘mixed fatty acid’ to be such an intended mixture of pure substances: The technology description of transesterification, generally part of the operational permission for Biodiesel plants according to the German Emission Control Act (BImSchG), does neither list the constituents fatty acid or fatty acid methyl ester as pure substance input, nor does it contain a ‘mixing facility’ or stipulations concerning a mandatory recipe for the preparation of such a composition – on the contrary, all descriptions always refer to transesterification as chemical reaction with the other phases to be processed (heavy phase, crude Biodiesel) and – if applicable – a diffuse separation phase to be treated separately. The fatty acid is generated as side product due to unavoidable side reactions, becomes ‘mixed fatty acid’ and cannot be simply isolated from the other constituents (Biodiesel, methanol etc.) without any additional process steps.

Does the registration as ‘mixed fatty acid’ have an impact on any current or intended use of fatty acids from oil refining?

Those are different substances. Due to the intended registration of ‘mixed fatty acid’ as a multiconstituent substance, there is a clear delimitation because the substance name must be formed according to REACh stipulations and thus consist of the main constituents.

Companies are recommended to also support this delimitation by only using unmistakable trade names in everyday business.  

The stipulation of the substances’ uses or their restrictions is always connected with a concrete substance und has no influence on other substances.

What is the connection between the handling of ‚mixed fatty acid‘ according to waste legislation and its registration under REACh?

Waste legislation and the new European Chemicals Law (REACh, CLP) are separate legal systems. The essential linking aspect is that – according to REACh – there is no obligation to register waste under REACh.

The classification of a substance as waste results from the company’s statement towards the relevant authority that there is an ‘intention to dispose of’ the substance. Thereafter the authority stipulates a detailed procedure (of disposal) which is mandatory for the company.

Mostly waste is insufficiently characterized substances with regard to their chemical properties. Therefore, the (German) so-called ‘TA Abfall’ (Technical Guideline on Waste) stipulates certain minimum test scopes to enable waste disposal companies to proceed appropriately, and to simplify supervision for the authorities.

Contrary to that, registration under REACh calls for detailed information on the chemical composition, the physical-chemical properties and the implementation. Therefore, the registration of substances under REACh is always more sophisticated than their disposal as waste.

Under certain conditions a substance can be registered under REACh and also be approved as waste according to an authority’s assessment. The actual form of ‘use’ is the company’s decision but documentation on that should always be clear and traceable.

Note: In Germany, the approval according to the Emission Control Act (BImSchG) must be adapted adequately. For that a revised application is essential.

Does the REACh registration of ‚mixed fatty acids‘ restrict the applicability of other legal regulations for this substance?

No. REACh has the objective to minimize the hazards of chemicals for humans and the environment and to also provide a supply guarantee within all of the EU/EEA.

Remark: It cannot be ruled out that European regulations, which need to be adapted to national ones (e.g. Energy Tax Law), will be interlinked with other nationally applicable regulations (e.g. Waste Law). One example may be that the stipulations concerning the eligibility for so-called ‘Double Counting’ could be dependent on the waste code number of the European Waste Catalogue (EWC) even if from a technical point of view that would present no desirable solution (1).

How should ‚mixed fatty acid‘ be registered?

It is intended to register it under the REACh-conform name of

Reaction mass of Fatty acids, C16-C18, C18 unsaturated and Fatty acids, C16-C18, C18 unsaturated, methyl esters and Methanol’.

(According to its internal regulations, ECHA is entitled to rearrange the order of the constituents.)

Other constituents (Alkali hydroxides, Alkali salts) are to be considered contamination/impurities, in order to avoid a split into many substances liable for registration.

Dependent on the technology applied, products differ quite significantly; especially with regard to the methanol content, one can anticipate already that there will be both registrants with a methanol content of < 1 % methanol as well as with a contents of significantly above that. 

In order to be able to unite both cases in a Lead Registrant’s dossier, the Chemical Safety Report (CSR) must be issued with two chapters regarding the effect of the differing methanol contents, since they will have a significant effect on the risk features. Specification will be stipulated in the company-specific dossier as well as the safety data sheet (SDS) of the company concerned.

Full registration or ‘Strictly Controlled Intermediate (SCI)’?

Apart from the standard registration as (fully characterized) substance (Full Dossier), it is principally possible to also register as so-called ‘strictly controlled intermediate (SCI)’. 

Though on the one hand lower ECHA charges are advantageous when registering as SCI, on the other hand there are also considerable disadvantages, because even after marketing the substance, significant responsibility remains on the part of the supplier:

-  The requirements of ‚strictly controlled‘ must be maintained uninterruptedly beyond shipment and transport up to the processing of the substance.

-  The recipient must convert the substance received into a new substance (so re-sale is excluded, for example).

-  Use by final customers must be definitely excluded.

-  The supplier is fully liable for the abidance by those requirements. Subject to private law and by means of a contract, he can commit the recipient to comply with the requirements; however, in case of non-compliance the supplier remains responsible as far as the enforcement authority is concerned.

In case of full registration those limitations do not exist any longer; but then ECHA’s registration charge is significantly higher.

AGQM will offer both registration alternatives to potential registrants.

Find here the FAQ-catalogue



1. The EWC was not founded with that purpose. Therefore, the classification is fairly approximate and may even lead to false decisions. In addition, it is practically impossible to rectify a waste code once it was assigned for a shipment. Principally one should question whether ‘intention to deposit’ and ‘second use’ (as prerequisite for Double Counting) have an identical meaning and contents.