FAQ's
1. What is Superwool 607 HT?
Superwool 607 HT is a high temperature insulating wool composed of man made vitreous (silicate) fibres having low bio-persistency.
Superwool 607 HT is an alkaline earth silicate (AES) fibre.
Its CAS number is 436 083-99-7.
Superwool 607 HT is designed for high temperature insulation applications with a classification temperature of 1300°C.
2. Is Superwool 607 HT patent protected?
Superwool technology is protected by a number of granted patents. The development of Superwool 607 HT has resulted in further innovative improvements for which additional patents have been applied for or obtained.
SUPERWOOL™ 607™ HT may be covered by one or more of the following patents or patent applications and foreign equivalents:-
US 5955389, EP 0710628, EP1474366, GB 2383793, GB04241907 and WO 03/059835.
A list of foreign patent numbers is available upon request to The Morgan Crucible Company plc.
THERMAL CERAMICS, SUPERWOOL and 607 are trademarks of The Morgan Crucible Company plc.
3. Which process is used to produce Superwool 607 HT?
Superwool 607 HT is produced from molten raw materials by the spinning method of fibre production. Thermal Ceramics has many years of experience using this manufacturing technology.
4. In which product forms is Superwool 607 HT available?
Superwool 607 HT is available in a wide variety of product forms:
Blanket, Bulk fibres (lubricated, unlubricated & engineered), Boards, Felt, Paper and Vacuum Formed products, Pyro-Logs, Pyro-Blocs™, Z-Bloks™ and Mastic products.
Please contact your Thermal Ceramics dealer for more details.
5. Are organic binders used in Superwool 607 HT products?
No binder is used in the manufacture of Superwool 607 HT bulk fibre, blanket or modules.
Organic binders are used for felt, vacuum formed shapes, boards and paper.
6. What is the classification temperature for Superwool 607 HT?
Superwool 607 HT has the highest classification temperature than ANY AES fibre product available.
Superwool 607 HT: Classification: 1300°C
High purity RCF: Classification: 1250°C
Magnesium silicate fibre: Classification: 1150°C
Superwool 607: Classification: 1100°C
The classification temperature is determined following the ENV1094-3 norm. It corresponds to the temperature for which the product has a permanent linear shrinkage measured using ENV1094-7 norm not exceeding 4% (for fibre).
7. Why is Thermal Ceramics introducing a new low bio-persistent fibre onto the market?
The development of Superwool 607 HT is part of Thermal Ceramics' commitment to provide the high temperature insulation market with low bio-persistent fibres. Until now applications above 1000ºC have not always been satisfied by the existing range of AES fibres.
This new product will satisfy the high temperature application needs and help customers fulfil their RCF substitution obligations.
8. Is Superwool 607 HT classified as a carcinogenic substance?
Superwool 607 HT is exonerated from the carcinogen classification in the European Union under the terms of Nota Q of Directive 67/548/EEC. Tests satisfying the requirements of Nota Q were conducted at Fraunhofer ITEM in Hannover, Germany.
All MMVFs, like some natural fibres, can produce a mild irritation resulting in itching or rarely, in some sensitive individuals, a slight reddening of the skin. Unlike other irritant reactions this is not the result of allergy or chemical skin damage but is caused by a temporary mechanical effect. Although classified as irritating to skin in Directive 67/548/EC, Superwool like other MMVFs show negative results when tested using approved methods (Directive 67/548/EEC, Annex 5, Method B4).
9. What is the EU Classification of Refractory Ceramic Fibres (RCF)?
The effect of a European Directive, 97/69/EC, published in 1997 was to classify RCF as a category 2 carcinogen. Since 1997, a number of downstream regulations have applied to the use of RCF and have resulted in increased costs of compliance for manufacturers, suppliers and users.
For a more detailed explanation please refer to Fact sheet 1 in the Superwool 607 HT launch documentation.
10. Does this mean that I (as a user) have to replace RCF with a low bio-persistent fibre - Superwool?
The existing European Health & Safety Regulations on the use of carcinogens at work state that the user has a duty to use alternative materials where they are technically and economically viable:
“the employer reduces the use of a carcinogen at the place of work in particular by replacing it, in so far as is technically possible, by a substance, preparation or process which, under its conditions of use, is not dangerous or is less dangerous to workers' health and safety”
This obligation does not apply to RCF applications already in place as long as the application is not releasing airborne RCF dust.
11. Is Superwool 607 HT a direct replacement for RCF applications?
Superwool 607 HT product range now offers a viable solution free of restrictions in terms of sales and use.
Superwool 607 HT can be used in place of RCF in most industrial applications up to the recommended use temperature for the specific product form. Please refer to product data sheets for detailed guidance.
12. Can I easily substitute 1260°C RCF with Superwool 607 HT or would I need to make changes to my technology?
Substitution should be straightforward with no significant changes to equipment design or application methods required. Please see the Superwool 607 HT Fact sheets for more detail.
13. Will it cost me more if I change from RCF to Superwool 607 HT?
It will most likely cost less!
Even though you are paying a price similar to standard RCF, you will not be required to comply with the same H&S regulations as exist for a product classified as a category 2 carcinogen, such as waste disposal, Personal Protective Equipment (PPE), exposure measures etc.
14. What is the chemical difference between RCF and Superwool 607 HT?
Superwool 607 HT is an AES fibre and contains predominantly Calcia and Silica while RCF contains predominantly Alumina and Silica.
15. What is Bio-solubility?
Bio-solubility is a factor which influences the bio-persistent of MMVF in the lungs. However it is not a recognised variable for exoneration from classification as a carcinogen under EU Directive 67/548/EEC.
Solubility measurement is a useful screening test in the course of fibre development and is normally measured in synthetic lung fluids.
Superwool 607 HT has been developed to show the improved high temperature characteristics required to act as an alternative to RCF whilst having similar bio-solubility to the other exonerated AES fibres (e.g. Superwool family of fibres).
16. Does classification mean RCF is a health risk?
The evidence which led to classification was drawn from animal experiments only and has since been contested. RCF has been in production for over 40 years, and there has been no human disease attributed to RCF fibre exposure. RCF products are not banned (except for direct sale to the general public), but users in the EU are required to consider and select alternatives with a lower hazard classification where technically possible.
17. Are there any safety recommendations available for using Superwool 607 HT?
A Material Safety Data Sheet (MSDS) is available for all forms of Superwool 607 HT as is required by European H&S regulations.
For workers' comfort, it is recommended that dust concentrations are kept as low as possible and below the applicable local exposure limit. General ventilation or another system preventing dust emission should be used. If dust exposure limits are exceeded, workers should be provided with appropriate and approved respiratory protective equipment.
Consideration should be given to the following advice to users: Practical experience has shown that Superwool 607 HT fibre may cause temporary mechanical skin irritation (e.g. redness or itching). It is therefore recommended that gloves be worn by operators handling the fibres repeatedly, clothing should be loose around the neck and wrists and precautions be taken (as described above) to avoid breathing dust. After handling, exposed skin areas should be washed with water and work clothing should be washed separately.
18. Will users of RCF find it easier to comply with H&S regulations when they use Superwool 607 HT?
The regulations which apply to a category 2 carcinogen in the workplace are not applicable in the case of Superwool 607 HT. Further guidance on these regulations can be found on the ECFIA website (www.ecfia.org)
Health and Safety practices when using Superwool 607 HT are “common sense” and apply to any activity that may generate dust in the workplace.
19. What are the exposure levels today and likely future changes?
Examples from some European countries are given in the table below. It should be noted that occupational exposure levels are established separately in each country and it is recommended that local regulations be consulted to establish the current and correct requirements.
| Country | Limit value for RCF | Limit value for Superwool | Comments |
| Sweden | 0.2 F/ml | 1.0 F/ml | |
| Norway | 1.0 F/ml (0.1 F/ml proposed) | 1.0 F/ml (0.5 F/ml proposed) | |
| Germany | 0.25 or 0.5 F/ml | 3 or 6 mg/m3 (Limit value for nuisance dust) or 0.5 F/ml | Limit value for RCF is 0.25 F/ml for new installations. Other installations is 0.5 F/ml |
| United Kingdom | 1.0 F/ml and 5 mg/m3 | 2.0 F/ml and 5 mg/m3 | |
| France | 0.6 F/ml | 1.0 F/ml | |
| Austria | 0.5 F/ml | 0.5 F/ml | |
| Italy1 | 0.2 F/ml | 1.0 F/ml |
1 Italy has no specific limit value for MMVFs but is referring to the latest ACGIH list of TLVs
20. How is waste treated for RCF and Superwool 607 HT?
RCF products containing more than 0.1 weight % of RCF are classified hazardous wastes under Directive 91/689/EC2. According to Directive 1999/31/EC3 such wastes can be disposed of in a non-hazardous landfill provided that leaching tests have shown there is no risk of soil or ground water contamination. In practice, many RCF users have experienced significantly increased costs on discovering that their local waste disposal site is no longer prepared to accept RCF waste.
According to EU Directive 1999/31/EC waste containing Superwool products can be disposed of in a non-hazardous landfill provided that leaching tests have shown there is no risk of soil or ground water contamination. In practice, Superwool users experience no difficulty disposing of waste fibre. This is a clear benefit for Superwool users compared with RCF users. Please refer to Fact Sheet 2 for more details.
21. Do I need to make changes to my working environment if I switch to Superwool?
Requirements for the use of RCF are normally more stringent and further modification is not necessary. However it is recommended to continue to use the ventilation systems in place as well as other organisational measures keeping dust levels low.
22. Does my workforce have to wear PPE (Personal Protective Equipment)?
The use of PPE is normally not required but may be necessary in dusty areas. In particular the use of respiratory protective equipment is necessary if the workplace dust concentration is above the applicable exposure limit value (see point 19).
23. Are there other products in the Superwool 607 family?
Superwool 607 and Superwool 607 MAX are available. Please contact your local Thermal Ceramics office for more details or visit our website at www.thermalceramics.com
24. What are the main applications of Superwool 607 HT?
Superwool 607 HT will generally be used for industrial insulation in ceramic kilns, the iron and steel industry, non-ferrous industries as well as in some domestic appliances. It has also found a range of specialised applications based upon its combination of low shrinkage and high temperature resistance.
25. How do I know if it will work in my application? Have any tests been carried out?
Prior to launching Superwool 607 HT, Thermal Ceramics has carried out a wide range of field trials in applications where standard grade RCF has been the normal choice. Advice on your application is therefore available and will be based on practical results.
References are available - please contact your local Thermal Ceramics office.
26. Is there any presence of crystalline silica in after use fibre?
As with any silica rich MMVF, when Superwool 607 HT fibres are heated to temperatures above 1000°C, devitrification may occur leading to the formation of crystalline silica This is the same effect as with RCF. Data from the CARE Programme, however, show the level of crystalline silica in the respirable fraction of the airborne dust (as measured on workers in furnace removal operations), is below the detection limit in the majority of the sampling tests. Controlling fibrous dust levels below the applicable exposure limit value will also ensure that crystalline silica exposure levels are not exceeded.
27. Why should I use Superwool 607 HT?
- Exonerated low bio-persistent product
- Does not react with high alumina bricks
- Classification temp of 1300 °C
- Low linear shrinkage
- Can replace RCF in most industrial applications
- Duty under EU Regulations to replace RCF where technically feasible
- Savings on waste disposal costs are possible
- Comply with H&S regulations & legislation
2 As amended by Decision 2000/532/EC
3 As adapted to technical progress by Decision 2003/33/EC