Scientific principles - gone? But not forgotten

The annual seminar at BLC is the visible sign of all the changes that have occurred in the company over the past five years or so. In have come the industrially experienced managers that were missing before, but added to this is the consolidation of the research manifested in the joint venture with UCN, the BLC Leathersellers Research Company. Also, the introduction of speakers from outside BLC has given a spark to the seminars. Dr Grant Darrie, from Elementis Chromium, said that life cycle analysis (LCA) is increasingly being seen as a vital tool in enabling high quality strategic decisions to be made. Approximately 10% of the chromite ore mined worldwide feeds the chromium chemicals industry and an astonishing, to me at least, 37% of that is converted into chromium tanning salts. The main players are Bayer (20% of production), Elementis (9%), Stoppani (9%) and Sisecam (9%) and so the leather industry is important to their production. Thus, the leather industry has a chemical partner in persuading the general public that using chromium is not an environmental problem. Dr Darrie said that Elementis are interested in co-ordinating a life cycle analysis, the scope of which will cover mining, the plant, tanning, use and end of life disposal. At the moment there is no cradle to the grave document available for chromium, but with the help of a French company, Ecobilan, who are life cycle analysis experts, Elementis hope to develop a cradle to grave document. A draft proposal was circulated to various companies, but there was no uptake. As Dr Darrie said: 'The battle should be entirely on scientific principles.' So, does chromium constitute part of an eco-leather? The question of what, generally, is an eco-leather, was given a quantified answer by Barry Wood. He said that: 'in the strict verbal sense the definition of the term 'eco-leather' has no formal meaning.' However, there is significant interest in leathers that imply improved environmental performance. Wood suggested that a measure of leather's eco-friendliness could be measured by the absence of certain chemicals, eg aromatic amines, pcp and, more recently, chrome and formaldehyde. And this is already having an impact. At Tanning Tech all the major chemical companies were displaying leathers that are chrome free and formaldehyde free. While they stress that chrome tanned leathers are still very much part of their repertoire, customer perception that chrome, or even mineral, free leathers are somehow more environmentally acceptable is coming to the fore, especially in the automotive sector. Here, the car companies want the leather in their cars to be recycled, particularly in Germany where the recycling of automotive parts will become law. There is a system for considering the lifecycle of a product. ISO 14040 defines a mechanism for determining the life cycle analysis of a product and it states that the important points to note in determining any LCA and the product's environmental impact are achieved by: * compiling an inventory of relevant inputs and outputs of a product system * evaluating the potential environmental impacts associated with these imputs and outputs * interpreting the results of the inventory analysis and impact assessment phase I relation to the objective of the study However, there must be questions as to whether this is worthwhile doing. If the public perception, or worse, the legislators' perception, is that chromium (III) is hazardous by association, then will 'proving' that leather car upholstery meets the ISO 14040 criteria set by the tanner, admittedly in agreement with some third party, actually make one jot of difference. It's the same argument that the likes of PETA use against the leather industry. They cloud the issue so that the facts are lost in fiction. But, the impact is very real. The conundrum is to show that the leather industry already has eco friendly leather - chrome tanned, and that alternatives are less eco-friendly. This is not an easy task. My personal opinion is that if we are to take eco-leather to its limit, one of the most effective ways of meeting the eco-leather criterion is not to produce it at all. Processes such as gasification would destroy the raw hides and skins. This would not only eliminate the problems of what to do with raw hides, but would also eliminate the waste caused by the leather industry. Using BLC figures, the production of leather involves the production of three times as much solid waste as leather produced. This figure was give in a presentation by Dr Warren Bowden and while some of the audience suggested BLC should be concentrating on the quarter that is useful, ie the leather, rather than the three quarters that is not, Dr Bowden highlighted the commercial options for disposing of solid waste. He said that waste includes: * sludge * trimmings * shavings * screenings * fleshings, hair and lime splits * domestic waste 'All of these can be disposed at present to land fill or some small scale 'reuse' options such as leatherboard. However, as a result of the landfill directive (1993/31/EC) phased reduction of organic biodegradable disposal will have to be to 35% of the current levels by 2015. With the increasing costs of landfill and transportation to the site, eventually such dumping is unlikely to remain an option. Biodegradable wastes, eg tallow, lime splits, pretanned shavings and screenings, can all be composted and with waste operators realising that organic byproducts can be a useful source of income, there are possibilities for the reuse of this waste. However, there has to be a market for the products to make the conversion process viable, so the outlook is more medium to long term than a quick fix idea. But, it is promising. The tanned waste and sludge can be treated and applied to agricultural land, where the nutrients benefit the land. Unfortunately, there are concerns about adding chromium to the land and these remain. Thus, the best way forward, Dr Bowden suggested, is probably via the recovery of energy. Leather derived wastes contain as much as 50% of the energy value of coal and with the advent of the climate change levy there is a need to generate renewable sources of tax exempt energy. One way of using leather waste is via gasification, a process that the Borge tannery in Norway has taken onboard. This was fully reported in Leather April 2000. The eco-labels that Barry Wood discussed are leading to other problems for the industry. This is in the form of so called standards that are set by bodies who do not know, or understand, the leathermaking process. Dr Amanda Long discussed the problems of formaldehyde determination. She quoted examples of formaldehyde limits set in various eco-labels. Put into context, the level of formaldehyde allowed in cosmetics is 2,000 mg/kg and even as a preservative in oral hygiene the limit is 1,000 mg/kg. Thus, the limits set by the standards have no scientific basis and seem to be pandering to public worries. Dr Long said that the current industry standard (DIN 53315) consists of two parts. Part A is a colorimetric determination of the extractable formaldehyde, while part B is a method based on HPLC. The determination can be done with either part. Work carried out at BLC showed that in tests on 76 leathers, using part A of the test, an astonishing 80% of the results were false positives. While the majority of these were below any of the levels set, the fact that the results could be misleading is worrying for an official method. BLC also found that for identical samples, part A yielded a variation of 10%, again poor for a method considered for official use. They found that the HPLC method gave results that were more consistent and have decided that this will be the preferred method of formaldehyde detection, unless otherwise requested. However, the question of whether the limits set are valid is still something to be discussed and it needs the industry to make a stand on the matter. We need to present a united front against non-leather organisations and bodies setting ludicrous standards that have no rational scientific basis. Dr Long again raised questions concerning testing in another lecture she gave. This time entitled: 'Is 48 hours conditioning prior to testing really necessary?', she said that with the just in time concepts run in many tanneries, having to wait two days before testing leathers was a significant delay and while 'historically two extra days on a thirty day process has a low impact, that was before the industry responded to demands on rapid response times.' The problem is that the 48 hour condition is written into folklore. From the initial results obtained at BLC, there seems to be no actual basis for it, indeed with some tests conditioning for a longer time had an adverse effect while with others, shortening the conditioning time was a problem. Another question that needs to be addressed is whether conditioning for 48 hours is enough! Dr Long showed some results that suggested that if the leather had been kept in a high relative humidity, 48 hours did not bring it back to the expected standard of 12-14% moisture content. She said that the results suggested: 'that leather that is received for testing at relatively low humidity can be conditioned for testing within 4-8 hours. This does not appear to apply, however, for leathers that have been previously stored at high humidity. 'By subjecting the leather to a gentle drying for 2-3 hours followed by standard conditioning overnight the time required prior to testing can be reduced significantly.' This is an interesting subject, which probably needs more investigation before coming to a definitive answer. Is money available for such research? Just as a final comment, Kerry Senior was discussing the environmental updates that were about to descend on the industry and he pointed out that the legislators dropped the 'NEEC' out of 'BATNEEC' (Best Available Technology - Not Entailing Excessive Costs), something that was not unexpected. However, what does seem surprising, to put it mildly, is that I understand the 'BAT' part doesn't have to be industrially proven: if it has been proven to work on a pilot scale then the authorities can be satisfied with that! I remember a 24 hour raw to wet-blue process that worked wonderfully on the pilot scale, but when introduced industrially was scuppered by the longer draining times and the sheer size of processing on that scale compared with a pilot plant trial. Surely something that becomes best available technology should be industrially tested? Or am I missing the point?