This group of chemicals is diverse and may cause a list of different effects on health and the environment.

Several of the compounds in this group may damage or are suspected of damaging the unborn child and/or reducing fertility. Some are suspected of causing genetic defects and may also cause cancer.

There are also examples of possibly endocrine-disrupting effects, although there are some disagreeing results. Several are very toxic to aquatic life and are very toxic to aquatic life with long-lasting effects.

Some of them may also fulfil the criteria as persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative (vPvB) compounds.


Function and use

The most common functions of some of the more specific substances included in this group are compiled below:


Carbon monoxide

Industrial gas, metal manufacture (does not end up in products).


Potassium bromate

Powerful oxidiser.



Lipophilic solvent.



Lipophilic solvent, cleaning or degreasing agent, denaturing agent, carrier for oil and beeswax.


Terphenyl hydrogenated

Lipophilic solvent, plasticiser in plastics.


Tert-butyl methyl ether




Building blocks in organic synthesis, used in fragrances, water scavengers, reactive diluents.



Flame retardants and plasticisers.


Organosilicones D4, D5 and D6

Monomers for silicone polymers and may be present as impurities, or as a solvent in dry cleaning. The main function of silicone polymers is anti-foaming, dewatering (to accelerate drying of clothes, fabrics, cars, vehicles), anti-wrinkling (of textiles) and perfume release agents.


Areas of application

Common uses for some of the more specific substances included in this group are compiled below:


Potassium bromate

Flour improver (mainly the USA), residues after baking.



Mothproofing agent (wool protection), binder.



Laboratory use, extraction of food oils and fats, degreasing and cleaning agents, gasoline, quick-drying glues, textile and leather adhesives, rubber cement, non-mercury thermometers, inks, paint thinners, leather work, manufacturing tyres, denaturing agent in some alcohol preparations, carrier/propellant agent in some perfumes.


Terphenyl, hydrogenated

Coatings, inks, adhesives, sealants, heat transfer fluids.


Tert-butyl methyl ether

Extraction solvent, oxygenate and octane improver.



Small heterocyclic compounds are in general very useful in the synthesis of more complex structures, for example dyes or solvents. Other heterocycles are used in industrial processes or as solvents. Some specific heterocycles include for example:

  • Galaxolide (HHCB): used in perfumes, cosmetics, cleaning agents, air fresheners and fabric softeners.
  • 4,4'-methylenedimorpholine: used as a biocide for preservation of cutting fluids.
  • Zoldine MS-PLUS: used in paints for polyurethane and sealants.



Common uses are as flame retardants, plasticisers and various additives.


Organosilicones D4, D5 and D6

Primarily used in washing and cleaning products, polishes and waxes, cosmetics and personal care products. Silicone polymers (where D4, D5 and D6 can be present as impurities) may be used in the formulation of detergents, wood/surface care products, shoe care products, tyre and car care products, insecticides and air fresheners. Also used as silicone sealants and adhesives, and in polyurethane foams for building insulation.



Several of these compounds are included in the Candidate List, some are restricted in REACH Annex XVII as well as the REACH Candidate List, and some are included in the CoRAP list.



Alternative approaches

Processes that involve any of these substances as solvents could in general be modified to solvent-free processes or to processes that use less hazardous solvents. To avoid D4, D5 and D6 silicones as impurities it may be possible to substitute the silicone polymers.

There are also devolatilisation techniques used in the production of silicone polymers to reduce the concentration of impurities of D4 and D5.


Alternative substances

Alternative compounds are available on the market, for example:


Water-based cleaners can replace hexane and other toxic substances.


Water-based adhesives are also safer substitutes for hexane in many consumer products.


In the printing industry, vegetable- and plant-based cleaners can be used instead of hexane.


FluidWorker is based on UV technology.



Nofia® OL1001 and Nofia OL3001 oligomers are phosphorus-based low molecular weight, reactive flame-retardant additives suitable for flame-retarding thermoset resins, such as unsaturated polyesters, epoxy, polyurethane and polyurea.


Professional wet cleaning (also known as for example Aqua Clean, Lagoon technology). Based on water and biodegradable detergents.


Degreasing agent in cleaning


Solvent-based adhesive



Degreasing agent



Biocide in process fluid



Flame retardant





Dry cleaning

Problematic substance

Hexane or other solvent


Hexane or other solvent



Hexane or other solvent





Triphenyl phosphate, trixylyl phosphate