Rapidly biodegradable hydraulic oils An Overview
Rapidly biodegradable hydraulic oils 2 Another verdict of the District Court Hamburg no. 312 O 795/05 dated 04.04.2006 describes the legal position as follows: «Users of machines in environmentally sensitive areas for insurance / liability reasons are furthermore obliged or even forced to only fill in oils and lubricants in their machines, which, if released to the environment, would result in the smallest possible damage to the environment.» For more than 20 years various rapidly biodegradable hydraulic oils have been offered in the market. Only few products managed to gain a significant market acceptance. Undisputedly we were able to do this with the rapidly biodegradable PANOLIN hydraulic oils. According to the IFAS statistics 2005 the market share for PANOLIN products was at 49% - seen in relation to the use of biodegradable oils in mobile machines (Germany). This is reason enough to give users and manufacturers of machines a current overview regarding the advantages and disadvantages of the different product groups. II. Definition «rapidly biodegradable» Rapidly biodegradable hydraulic oils the emphasis in this case is on «rapidly» - are often identified with the simple description «bio oil». This is insufficient if there is no detailed reference to the test method by which the biodegradability has been determined. As a test method for the biodegradability the test methods according to OECD 301x have established themselves internationally. These test methods are also mentioned in the current ISO 15380:2002 standard and are an essential basis for awarding the current Eco Labels such as e.g. Euro-Marguerite (R1, T3) or Blue Angel (RAL-UZ, since 01.01.2006). I Background Description, general and legal point of view Rapidly biodegradable oils are used mainly in environmentally sensitive areas. In stationary systems rapidly biodegradable hydraulic oils are used mainly due to legal requirements. The verdict of the District Court Hamburg no. 312 O 730/06 dated 16.01.2007 states the legal position as follows: it is to be observed that for the user of a machine deployed in environmentally sensitive areas, such as nature and water preservation areas, there could be risks of liability that may even threaten the company s existence in case of hydraulic
Rapidly biodegradable hydraulic oils 3 III. Valid standards The current internationally valid standard for the classification of rapidly biodegradable hydraulic fluids in the respective material groups is ISO 15380 (2002). The precursor of this standard was VDMA 24568 (1994). That is a technical rule which has never been conveyed to a standard, but is nonetheless widely cited. Nevertheless there is a certain conformity with the standard ISO 15380. A correct and clear reference to a standard for rapidly biodegradable hydraulic oils is generally possible with ISO 15380. IV. Correct and complete identification of the biodegradability The simplified description «bio-oil» or «biodegradable» without a concrete reference (with percentage indication) of the used and approved OECD 301x test method in this context is incomplete. If ISO 15380 is indicated, this includes that the biodegradability has been tested according to OECD resp. ISO. The best known Eco Labels and national requirements can be summarized as follows: EC: Biodegradability according to OECD 301x Euro-Marguerite (EC/360/2005) Germany: Like the EC, additionally: Blue Angel RAL-UZ 79 (Edition 02/2005) Water hazard classification WGK nwg or 1 according to VwVwS-99 Austria: (amended in 2005) Like the EC, in parts also the German Blue Angel and the German water hazard classification are accepted. Additionally: ÖNORM C 2027: 1997, part 5 Scandinavia: Like the EC, additionally: Swedish Standard SS 15 54 34 Czech Republic: Like the EC, additionally:czech Ecolabel/Ekologicky Setrny Vyrobek 15-02 USA: Canada: Japan: Korea: in parts like the EC and also the German Blue Angel is highly respected, additionally: ASTM D6046-02(2006): P W 1, T W 1, T S 1 in parts like the EC and additionally: Environmental Choice Programme CCD-069 Japan Environment Association-Eco Mark Like the EC and additionally: Korea Eco-Label and ASTM D6046-02(2006): P W 1, T W 1, T S 1 This overview does not claim to be complete. Users who employ their machines internationally can only expect absolute acceptance if the employed products correspond to the standards of the respective country although internationally there is a strong coherence of the criteria.
Rapidly biodegradable hydraulic oils 4 V. Water hazard classification WGK All Fluids are being classified in three classe according to the VwVwS valid in Germany: WGK-1 low hazard to waters WGK-2 hazard to waters WGK-3 severe hazard to waters When using rapidly biodegradable hydraulic fluids in mobile machines the WGK at best has a secondary relevance. Primary in such applications it is the matter of biodegradability. When used in stationary plants in contrast the WGK has relevance. WGK classes primarily are valid in Germany but are understood in many countries. They cannot, however, be simply read-across although there is a strong overlapping of the limiting values with the EC directive EC/1999/45. Therefore generally the regulations for filling of stationary as well as mobile machines outside Germany are mostly oriented on the rapid biodegradability and the three aquatic toxicities (fish, algae and daphnia) as well as bacteria in ISO 15380. VI. Technical Performance Level Machine and component manufacturers can define their own performance level. Therefore it is reasonable that the biodegradable hydraulic fluids have an application approval from the respective machine and component fabricants. Comprehensively the following tests / performance levels are approved: Wear protection test: FZG Test A/8.3/90 12. load stage (DIN 51354-2 resp. ISO 14635-1:2000) Vickers 35 VQ-25m V104 C Oxidation stability: ASTM D 943-04 (Dry TOST) > 1.000 h Rotary-Bomb-Test > 1.000 Min. (is rarely indicated resp. passed by only few and very high performance products) Technical minimum requirement: Defined in ISO 15380 resp. VDMA 24568 VII. Overview of biodegradable hydraulic oils with short description In the sector of the rapidly biodegradable hydraulic fluids according to ISO 15380 (VDMA 24568) there are 4 structured material product groups: 1. Vegetable oils, abbreviated to HETG (Hydraulic Oil Environmental TriGlyceride) Due to their very restricted temperaturestability as a result of their «double bond», HETGs did not become accepted, especially for technically demanding/ sophisticated applications. Also disadvantageous is the natural fluctuation of the spreading of the molecular weight which differ seasonally and regionally. 2. Polyglycol oils, abbreviated to HEPG (Hydraulic Oil Environmental PolyGlycol) HEPG oils are very sophisticated products. In certain circumstances they are not compatible with a lot of paints as well as sealing materials and hoses and have been banned by some machine manufacturers in the meantime. Depending on the molecule type they are not, or are only partially oil-soluble. When the
Rapidly biodegradable hydraulic oils 5 HEPG oils get into the environment (due to a leakage or an oil accident) the products containing ethylene oxide do not offer any advantages because they rapidly mix with water and will settle to the ground due to their higher specific density (not for PPGs). Numerous types are classified WGK 1. Today polyglycols can not accomplish the criteria of renewable resources for obtaining ecolabels. Due to the above mentioned reasons, HEPG oils have only a small market share in the sector of the rapidly biodegradable hydraulic oils. 3. Synthetic Esters, abbreviated to HEES (Hydraulic Oil Environmental Ester Synthetic) In case of synthetic esters oils and within the same HEES-group the users have the choice between two groups: Unsaturated synthetic ester products mostly contain (similar to HETGs) vegetable resources. Because of the unsaturated composition they have only restricted thermal strain. The low temperature stability is lower and gets worse after longer service life. Some manufacturers of mobile machines advise against the utilisation of unsaturated ester products. Saturated synthetic ester products currently offer the most established positive application advantages for a longer period of time. From the material point of view saturated synthetic ester products have the advantage that they can be produced both from renewable resources and fossil resources. The mainly technical advantages can be found in the area of e.g.: high temperature and ageing stability (long changing intervals) improved cold start properties very good wear protection and good compatibility with sealing materials, paints and hoses 4. Polyalphaolefins, abbreviated to HEPR (Hydraulic Oil Environmental Polyalphaolefine and Related Products) HEPR hydraulic fluids are not completely indisputable as rapidly biodegradable products. The reasons for that are complex. For the production therefore generally only low viscosity PAOs or hydrocrack-base oils with high NOACK volatility values (!) because only those are barely biodegradable can be used. A higher viscosity is then effected with nonbiodegradable VI-improvers or highly viscous esters. At best this will lead to a WGK 1. HEPR oils frequently have the following 4 disadvantages: a. If they reached a high viscosity with a high percentage of VI-improvers, they are generally not sufficiently shear stable for a longer service life and are also volatile. b. Due to their composition they show a relative similarity to mineral oils and after an oil accident they will be detected as mineral oils (DIN 38409-H), as both material groups chemically are hydrocarbons. c. The mineral oil content in a HEPR fluid can not be determined reliably with periodical oil analyses. d. In case of oil leakages in water HEPR oils, like mineral oils form an iridescent film. All these points summarized from the market experience make clear, that the HEPR products mostly do not accomplish the expectations a user normally has with regard to a rapidly biodegradable hydraulic oil.
Rapidly biodegradable hydraulic oils 6 VIII. Miscibility with conventional and biodegradable hydraulic fluids with each other Generally the mixture of all rapidly biodegradable hydraulic fluids with each other as well as hydraulic fluids according to DIN 51524 is not allowed because of the different disposal codes. Foreign oil levels, especially mineral oil, may not exceed 2%. It is not possible to offer reassurances above this level as it does not conform with the relevant standards, and will not be accepted by machine and component manufacturers under the terms of their guarantee. Mostly it is stressed that a mixing will lead to the cancellation of any guarantee claims. Generous «miscibility approvals» are generally formulated by the oil suppliers themselves, are therefore commercially motivated but usually without any technically traceable basis. IX. Compatibility with sealing materials and hoses Even after more than 20 years of practical experiences there (unfortunately) is no simple and generally valid statement for this point. The reason for this is the fact that the hydraulic fluids as well as the different elastomers are chemical mixtures. The past 20 years however have influenced their development mutually. From today s point of view it can be confirmed that most of the conventional sealing materials and hose materials are compatible with most of the synthetic ester oils used. HETG and HEPG products are seldom used; that is why in this case an individual compatibility check is advisable. For the HEPR products it strongly depends on the specific formulation. If they contain esters as viscosity improvers, it has to be assumed that the characteristics of the esters will also be found in HEPR products. Otherwise it is advisable to note that several sealing materials swell slightly when in contact with PAO oils, whilst a lot of sealing materials actually shrink. At the moment the manufacturers of sealing materials refer to the more commonly occuring products as being wholly compatible with synthetic esters. The same is being stressed by the manufacturers of hoses. However, all general statements are still dangerous because there are neither only good nor only bad sealing materials, nor only good nor only bad fluids. The differentiation already starts with differently formulated mineral oils and continues with synthetic and rapidly biodegradable fluids. Categorical statements that which do not consider this variation can be considered as too highly sales motivated, and can therefore represent an incalculable risk for the user.
Rapidly biodegradable hydraulic oils 7 X. Summary Since the beginning of their development more than 20 years ago rapidly biodegradable hydraulic oils have extended their marked share on national and international level. In many cases they have become indispensable from an environmental view point, whilst at the same time economic aspects have been brought into focus. Saturated esters in particular have proven to be suitable for long-term use and do not introduce extra cost over the life of the product. The thought of the environmental protection is irreversibly and constitutionally positioned. Rapidly biodegradable hydraulic oils are an integral part of the sustained environmental thought and efficiently contribute to the environmental protection. The petroleum resources which are becoming more and more scarce and more and more expensive give a further economic entitlement to the increased use of lubricants from alternative resources. So for the future a further important advantage of the synthetic ester products is their material flexibility. Today these can be produced from petrochemical and renewable resources. This aspect will become more and more important. Rapidly biodegradable hydraulic oils from the PANOLIN product range: HEES: HEPR: PANOLIN HLP SYNTH, fully synthetic high performance hydraulic fluid on basis of saturated synthetic ester. Practically tested since more than 20 years. PANOLIN GRO SYNTH, fully synthetic high performance hydraulic fluid on basis of saturated synthetic esters with 50% share of renewable resources. Since the year 2000 with very good practical results in the market. PANOLIN HEPR SYNTH, biodegradable high performance hydraulic fluid on basis of synthetic hydrocarbons.
For the professional revision, corrections and amendments of this brochure I would like to thank: Dr. Matthias Woydt Bundesanstalt für Materialforschung und prüfung (BAM) (Federal Institute of Materials Research and Testing) Dr. Heinrich Theissen IFAS RWTH Aachen Dr. Gabriele Peterek Fachagentur für nachwachsende Rohstoffe e.v. (FNR) (Agency for renewable resources) Milorad Krstic / Chairman, February 2007 All rights reserved. Reprint even in parts is not allowed. No part of this brochure may be reproduced or edited, duplicated or processed by using electronic systems without written consent of the KLEENOIL PANOLIN AG, Dogern. KLEENOIL PANOLIN AG D-79804 Dogern Telephone: +49 7751 8383-0 Fax: +47 7751 8383-29 www.kleenoilpanolin.com info@kleenoil.com KLEENOIL PANOLIN AG / 20070301