RTV-1 silicone adhesive for food contact and addition cure silicones
Wacker ELASTOSIL® E43 N Transparent is a one component, condensation curing silicone adhesive based on acetoxy chemistry. It cures at room temperature under the influence of air moisture to form a permanently flexible silicone rubber with very good mechanical properties. The consistency ranges from non slump to self levelling.
The key difference from the standard E43 is that E43 N does not inhibit the cure of platinum cured addition silicones, and that once fully cured and given appropriate processing it is suitable for the manufacture of articles intended to come into contact with food. Available in 90 ml and 310 ml cartridges.
Key benefits
- Suitable for food contact: once fully cured and provided appropriate processing, see the conditions below
- No inhibition of addition cure silicones: does not interfere with platinum cured silicones, essential in silicone workshops
- Non slump to self levelling: thixotropic, stays in place on vertical surfaces and flows out smoothly on horizontal ones
- High mechanical strength: tensile strength 7.8 N/mm² and tear strength 12.5 N/mm
- UV and weathering resistant: retains elasticity and transparency under prolonged UV exposure and changing climatic conditions
- Electrically insulating: suitable for electronics applications, potting and sealing of components
Typical applications
- Assembly and repair of culinary silicone moulds and kitchen utensils
- Silicone workshops: bonding and sealing alongside platinum cured silicones without inhibition risk
- Electronics and potting: sealing of components, sensors and housings
- Household appliances, machine building, heating and cooling
- Formed in place gaskets
- Laboratory and workshop: general purpose silicone adhesive for repair and assembly
Food contact
Provided appropriate processing, fully cured ELASTOSIL® E43 N Transparent is suitable for the manufacture of materials and articles intended to come into contact with food according to Regulation (EC) No 1935/2004. Compliance of the finished article must be ensured by its manufacturer. Regulation (EU) No 10/2011 does not apply, silicones are excluded from its scope. Regulation (EC) No 2023/2006 does not apply either, as this product is a starting material.
National and regional assessments according to the Wacker Regulatory Product Information:
- Germany, BfR Recommendation XV Silicones: the ingredients comply, with a limit of maximum 0.5 percent volatiles for the cured elastomer
- France, Arrêté of 25 November 1992: compliant, maximum 0.5 percent volatiles, total migration from the finished article maximum 10 mg/dm² or 60 mg/kg
- United States: a food contact statement can be provided separately upon request
- Brazil and Mercosur: the ingredients are listed in ANVISA IN 435/2026 and/or Mercosur GMC Resolution 34/2025, maximum 0.5 percent volatiles and maximum 0.5 percent extractables
- China: the product does not comply with GB 9685-2016 and does not comply with GB 4806.16-2025
Conditions for food contact use: the product must be fully cured, acetic acid must no longer be released when the product contacts food, and the product contains small amounts of residual solvents that must be removed from the finished article.
The admissibility of the ingredients does not mean that the final product is considered safe for food contact by regulatory authorities. Responsibility for the finished article and for migration, extraction and volatiles testing rests with the manufacturer of that final product.
Technical characteristics
Comparison with E43: E43 N has a higher tensile strength than the standard E43, 7.8 against 6.5 N/mm², and a lower elongation at break, 450 against 500 percent. Its distinctive advantage is that it does not inhibit the cure of addition silicones. Choose E43 N when working alongside platinum cured silicones or when food contact is involved.
Processing instructions:
- Abrade the substrate and remove dust and contamination
- Degrease with white spirit or alcohol and allow to evaporate completely
- Apply E43 N and spread evenly
- Skin formation after 5 to 10 minutes at 23 °C and 50 percent relative humidity
- Through cure approximately 1.6 mm per day. The cure rate is limited by moisture diffusion into the rubber, so free access of air moisture is essential
- Heat curing only for layer thicknesses below 0.5 mm, otherwise blistering occurs due to the rapid release of acetic acid
- For food contact applications, allow a full cure until no more acetic acid is released and the residual solvents have left the finished article
- Always run preliminary tests on the actual substrate
Safety information: during curing a total of approximately 3.5 percent by weight of acetic acid is released. Work only in well ventilated areas. Avoid contact of the uncured product with eyes and mucous membranes. In case of eye contact, rinse immediately with plenty of water. The product is not classified as a hazardous substance or mixture under Regulation (EC) No 1272/2008. Refer to the safety data sheet for full information.
Wacker Chemie has more than a hundred years of experience in silicone technology for industrial sealing, electronics and food contact applications.
Technical support
Our technical specialists advise on substrate preparation, adhesion properties, the difference between E43 and E43 N, and optimal results for your specific sealing or bonding application. Contact us for the technical data sheet, the safety data sheet or the Regulatory Product Information.
