CORE-CHEM LTD has been specializing in precision component cleaning for many years and has put together the following information in a hope that some clarity can be brought to bear on the current TCE issues. At the moment confusion still prevails over what you can do to resolve concerns regarding the use or not of TCE and many people are getting conflicting information and feel they are left with no option but to purchase expensive new equipment. This is not necessarily the case and the following information may help to clarify what some of the options to resolve the issue may be applicable to your situation.
BACKGROUND:- Under the Solvent Emissions Directive (SED) 1999/13 EC and the Pollution Prevention and Control (PPC) regulations 2000 which should have been implemented by the 31st of October 2007. In these documents TCE having been classified as an R45 risk phrase solvent (may cause Cancer) and carcinogenic CAT 2 re classification also meant that every user should seek an alternative to TCE be found in the “SHORTEST POSSIBLE TIME”. It also limited the allowable consumption to 1 Ton per anum. Due to various issues being raised the EU solvent manufacturers in agreement with the EU HSE departments and DEFRA type organisations agreed to a voluntary EU Charter which effectively says that unless TCE is used in sealed or enclosed technology equipment system they will no longer supply the customer from 31st of December 2010. This of course also enables existing users to continue using TCE until the 2010 new deadline. Most users of TCE should have already had copies (from the manufacturers or their distributors) of documents they would be asked to sign. The first is a declaration of awareness which effectively asked them to acknowledge the requirement to have enclosed or sealed technology equipment before the deadline date for continued supply in 2010. The second is a declaration of conformity which effectively states that the customer has the new technology equipment thereby ensuring continued supply of TCE beyond the 2010 deadline. It does not detract from the 1 ton limit and the need under the SED and PPC to seek an alternative in the shortest possible time contrary to popular belief.
The problem for TCE users is that if they continue to use TCE they are still using a carcinogenic material, they will have to purchase new and in a lot of cases expensive equipment packages. Some of these restrict the option regarding the type of solvent they can use to either TCE or Perchloroethylene (PCE) meaning that if the legislation should change in the future again the new alternative solvent options would not be able to be used within these machines. Some of the new equipment also increases process times to 20 – 40 minute cycle times per basket, again something that a lot of users cannot accept. It would also appear that the manufacturers of TCE also are only going to supply the solvent in bunded containment vessels that often are rented to the customer for £70 - £80 per month and already the prices for TCE has escalated several times and is likely to continue to do so as the volume of sales reduces to the more effective equipment systems using lower volumes of solvent. There are alternative sealed or enclosed equipment packages available that give flexibility in the full range of non flammable solvent alternatives to TCE and can also use TCE or PCE as well. These also can offer process times of 3 – 10 minutes per basket load which is comparable with most user requirements and enable the user to continue producing clean parts in a complaint and efficient way below the 1 ton thresholds in most cases. Further details available from Core-Chem Ltd on application.
SO WHAT ARE YOUR OPTIONS;- In simple terms starting with the cheapest option as follows;-
1. Establish that the degreasing you are doing is essential; often companies degrease because they have always done it and have never considered the best way to machine and clean parts by use of different oils or reducing inter stage cleaning for example.
2. Review your process methods often minor changes in process methods can reduce solvent consumption dramatically via a solvent reduction scheme.
3. Be sure that the equipment you are using is capable of being converted to become compliant before making the decision to buy new equipment.
4. Evaluate fully the alternative solvent/chemical options via both trials and direct contact with end users who have the real experience of its use, because clean fresh chemistry should do a good job, but will it still be capable when it has been in use for a longer period of time. It is worth bearing in mind that of the alternative solvents most will not work as effectively as TCE in vapour only form, so if this is your preferred method of use i.e. vapour only, some of the lower boiling solvents should be discounted as they are both more expensive and have poor vapour degreasing capability due to their low KB or solvent power value. You may be able to achieve the same levels of cleaning using these if you go to immersion/ultrasonic cleaning but then your intial fills will be considerably higher and the cost of setting up the system will equally be high.
More details on the various solvent chemistries and the advantages/ disadvantages are available via the Core-Chem Trike support team. All of the non flammable solvents are capable of doing a reasonably good degreasing job but you must get the balance of solvent power, boiling point, substrates to be cleaned, contamination to be removed and process method right before accepting the recommendations for a particular solvent prior to carrying out trials.
5. Assess the equipment options and ensure that they can accommodate ALL the alternative non flammable solvent options by simply changing temperature settings. When looking at the equipment options be sure that the process times are in line with your production requirements. Look closely at process times per basket. Be sure that the option you are looking at can use any non flammable solvent not just TCE or PCE. Something else to bear in mind is that some of the sealed systems are supposedly zero or low emission machines but it is important to establish the level of wastes generated by these as they often have the need for a replacement barrel every month or so due to high acidity levels an additional cost that is not always made clear to you. Finally if you intend to stay with TCE in a new technology sealed or enclosed machine you may find that you can only get the solvent in the suppliers approved bunding systems which can add to the cost of the product and often there may also be an additional cost for the rental of these between £70 - £80 per month (again the Devil is in the detail). Based on recent circumstances prices are very likely to continue to increase in the coming months if what we are constantly being told by our customers is anything to go by.
6. Some people may suggest the use of water based technology and in some instances this can be a valid option. However choose very carefully when precision component cleaning basic cheaper spray wash systems are not that efficient and a more sophisticated immersion/spray/ultrasonic option may be more justified. With regards to the water based options also bear in mind that these can use a lot more energy and generate a lot more waste which gives a far higher carbon footprint and over the coming months/years we are likely to hear far more about taxes on systems that generate a bigger carbon footprint which supposedly adds to the Global warming that every major country is becoming more concerned about.
OTHER THINGS THAT MAY BE WORTHY OF FURTHER THOUGHT FOR THOSE WHO ARE OR FEEL TIED TO THE USE OF TCE;-
All too often people say there is nothing that can clean as well as TCE and I would be the first to say that TCE is a good cleaner because it has a combination of a high solvent power an upper mid range boiling point and in terms of vapour only cleaning is ideal for that application.
This also raises the question how is TCE mainly used and it tends to be predominantly within the aerospace industry and their sub contractors via vapour degreasing method, where approvals are essential. If you are in this sector, now is the ideal opportunity to evaluate alternative solvent chemistries and talk to the OEM’s about what you can use as an alternative in most cases the OEM will accept an alternative approval or may even be investigating the technology you are looking at and will often give an NTO (No Technical Objection) certificate to enable you to use this material in preference to TCE.
If you cannot afford sealed or enclosed technology equipment at this time. It is also worth talking to the Carbon Trust who can often offer interest free loans to companies who are getting more energy efficient and safer modern equipment. Link is www.carbontrust.co.uk
We hope this information clarifies some of the points related to the TCE issue. It is a complex subject, and as independent process solution specialists, we are able to explain and support you in evaluating your options. Our Trike support team can offer much more specific data on any of the above mentioned data.
Further information regarding equipment types and or alternative solvent /water based options and solvent reduction is available from the Core-Chem Ltd Trike support team e-mail our team on trikesupport@core-chem.com . Or simply ring us on 01753-819496 and one of our team will be pleased to arrange a free site survey visit to assess your requirements and help take you through the minefield safely and environmental compliance.