Chloro Alkanes Product Group
The interests of European chloro alkane producers are represented by the Chlorinated Alkane Product Group (CAPG, part of Euro Chlor) which works to promote best practice, support the long-term sustainability of the chlorinated alkane industry, and to demonstrate just how essential these substances are to society.
The following companies are Members of the chlorinated alkanes PG:
Chlorinated alkanes (or chlorinated paraffins) are highly versatile chemicals that give essential, often life-saving properties to those products that contain them.
They are produced by the chlorination of n-paraffin or paraffin wax, which also forms high-grade hydrochloric acid (which in turn has its own uses).
Commercial chlorinated alkanes contain 30-70% chlorine, are largely inert, practically insoluble in water and hardly evaporate. Most commercial products are liquid with a range of viscosities, depending on the degree of chlorination (more chlorine equals greater viscosity/ density). There are also solid types that have longer carbon chain lengths, containing 70-72% chlorine. Chlorinated alkanes are also capable of mixing with many organic solvents. This diversity makes chlorinated alkanes highly versatile in their number of applications.
Chlorinated alkanes are generally grouped into a number of distinct ‘families’, depending on their carbon chain-length:
- short-chain: based on C10-13 paraffins (no longer produced in Europe); SCCP
- medium-chain: based on C14-17 paraffin; MCCP
- long-chain: based on C18-20 (liquids), C>20 (liquids) and C20 wax grades (average carbon chain length approximately C25); LCCP
The difference in the size of the molecule is important when considering their application. There are also regulatory aspects as well, with different chain lengths and chlorination patterns leading to fundamental differences in their properties. The total EU production of medium and long chain chlorinated alkanes is approximately 45,000 tonnes per year.
Chloro Alkane Benefits
The largest application for chlorinated alkanes is as a plasticiser in flexible PVC. Chlorinated alkanes (CAs) have a diverse range of uses, and are a class of versatile chemicals that have been in safe use for over 50 years, particularly in settings where chemical stability is essential.
Chlorinated alkanes are essential for safety.
In industrial paints, CAs impart fire retardancy. Solvent-based LCCP coatings are widely used across Europe and whilst some alternatives may exist, there are significant compromises on performance and cost-effectiveness.
Higher chlorine content CAs are used as flame-retardants in a wide range of rubbers and polymer systems, where they are often used in preference, particularly in challenging environments where fire-risk must be controlled (e.g. mines).
CAs are also found in cables where they protect the surroundings from the electricity running through the cables. Here, not only do they protect people and buildings from fire but they also remain embedded in the cable polymer and do not leak into the environment.
“No solvent-based formulation has produced as good a performance for intumescent paints as LCCP” – CEPE member
Chlorinated alkanes are safe to work with.
In metal working fluids, MCCP gives a low viscous material that does not mist and can be used in lower quantities than alternatives. They also have lower odours and do not react with the metals being cut as easily. Due to this, it is easier to remove from the metal than other materials saving energy and improving waste quality. CAs are commonly used to make single sheets of steel for items such as fuel tanks, car parts and even kitchen sinks!
” We are not aware of any readily-available alternatives to chloro alkanes that provide the necessary performance characteristics for extreme-pressure metal working fluids.”- ILMA member
Chlorinated alkanes are hard-wearing.
CAs give road-marking paints, rubber-based paints for agressive marine and industrial environments and exterior masonry paints much needed physical, chemical and water resistance.
CAs are also essential in plastics where they impart flexibility without being lost from the polymer over time (e.g. in hard-wearing flooring materials).
Chlorinated alkanes are environmentally conscious.
CAs boost the performance of metal working fluids. CAs in metal working/ extreme pressure additives are particularly useful for stainless steels and very hard metals where other additives may not be as effective. In such settings, as they react with the metal at a specific temperature range and have low viscosity, they reduce the amount of energy needed. Further, in some metal working environments, there are a limited number of equivalent, safe, suitable alternatives that perform as well as CA. In PVC, CAs can be recycled back into other rubber compounds with >50,000T of MCCP-containing PVC is being recycled each year.
“CA’s have up to 44% lower carbon footprint through their lifecycle than other PVC additives” – Manchester University Research
Chlorinated alkane regulations in Europe
CAs are under a high degree of regulatory scrutiny, with one of the main questions being how much can legally be in a product or material. Much of this is due to the regulatory environment surrounding SCCPs and mistakes people make when they define CAs. Unlike MCCP and LCCP, SCCPs are classified as SVHCs (Substances of Very High Concern) and have not been produced in Europe for many years as they are subject to authorisation.
Notification to ECHA is a legal requirement for imported consumer products which contain >0.1% w/w SCCP. Often, there are claims that SCCPs “appear in products” above the limit or, even more incorrectly, in European MCCP/LCCP products. However, SCCP and MCCP/LCCP are very different ‘chemicals’.
It is important to distinguish between SCCP and short carbon chain components of other longer chain UVCB substances. Regulatory action on SCCPs is on the substance as defined by CAS No 85535-84-8/EINECS 287-476-5, which have been tested fully. This includes chain lengths from, predominantly, C10 to C13 and their concentration in longer chain chlorinated alkane products (such as medium chain chlorinated paraffin (MCCP) or long chain chlorinated paraffin (LCCP)) is always zero.
Similarly, MCCPs are defined by specific CAS and EINECS Numbers (85535-85-9/287-477-0). These are chain lengths of, predominantly, C14 to C17. There remain some constituents of MCCPs which lie outside this range, however these are part of the substance and will have been present when the substance was tested in regulatory required assessment. For MCCPs (and MCCP products), when small amounts of chlorinated components, that are less than 14 carbon atoms long are found, they are not SCCP but rather <C14 constituents that are part of the registered MCCP product which is a UVCB substance. SCCPs and MCCPs are not blended together, nor are C13 components added to MCCPs. MCCPs are not defined as a mixture under REACH but are defined as substances.
Chlorinated molecules can potentially also be found in chlorinated alkane products produced outside the EU (i.e. in imported products). It is important to note though that, in other global regions, chlorinated alkane substances are not always categorized by carbon chain length, but by chlorination level (e.g. China). This means that CA products used in imported consumer products could in fact be composed of other carbon chain length ranges (e.g. C10-20, 52%Cl in China). As such it is not correct to assume that any <C14 chloro alkanes found in imported products are SCCPs, as defined by the above CAS and EINECS numbers.
There are tens of thousands of possible chloro alkane chains that can be potentially found in CA products. This is amplified by analytical problems and poor availability of relevant testing standards. Find out more in our presentation on this fascinating, but crucial subject!
Under REACH, additional lab testing has taken place to identify the properties of MCCP to show they are not toxic, persistant in the environment or accumulative in animals. Existing studies show that medium and long chain CAs:
- are not very volatile,
- are chemically very stable,
- will adsorb strongly onto sediment (so will not end up in water),
- will degrade due to the activity of bacteria (particularly true for lower chlorine content CA, 80% within 42 days)
- do not biomagnify in fish
- do not show any measurable toxicity in several species of fish
- do not mimic oestrogenic compounds
- are not significantly absorbed through the skin
- are not skin sensitisers
- do not have a mechanism in humans that could lead to cancer
Given the range of lab studies on these molecules and as they have been used for many years, their risk management is well characterised. As such, sensible and scientific risk assessment shows that these versatile chemicals can be safely used.