Before working with this product, you must read and become familiar with the available information regarding its risks, proper use, and safe handling. This information is provided in various formats, including the current Safety Data Sheet (SDS) and product label. SDS can be accessed via the following link:
Safety Data Sheets (SDS) for Covestro products | Covestro
For further questions, please use the contact information provided on this technical data sheet.
Product description
Caustic soda 50% is a solution of sodium hydroxide (NaOH) in water and is commercially available in the following grade:
Name: Caustic soda 50%
Percent by weight: 49 – 51 %
Caustic soda 50% is supplied in rail tankers, road tankers or ships, and by pipeline from the Leverkusen, Dormagen and Tarragona Chemparks.
Applications
Technical chemistry: Production of soaps and detergents, dyestuffs, sodium compounds, regeneration of ion exchange resins
Aluminum industry: Production of fused alumina by bauxite pulping
Pulp and paper industry: Soda cellulose and sulfate cellulose production
Textile Industry: Production of viscose silk (synthetic wool)
Electrical Vehicles: LiOH production, cathode active materials production
Various: Neutralization, alkalization, degreasing, pickling of metal surfaces
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Caustic Soda (NaOH) | 49 - 51 | % | 2042-0400401-16D | |
| Chloride | 60 | mg/kg | 2042-0404001-16D | |
| Sulfate | 40 | mg/kg | 2011-0572501-99D | |
| Carbonate | 150 | mg/kg | AC-F 1249 | |
| Chlorate | 15 | mg/kg | 2011-0572501-99D | |
| Silica (as SiO2) | 10 | mg/kg | 2042-0411701-16D | |
| Iron (as Fe2+ a. Fe3+) | 5 | mg/kg | 2042-0411701-16D | |
| Aluminium | 1 | mg/kg | 2042-0411701-16D | |
| Alkaline Earths (as Ca^2+) | 5 | mg/kg | 2042-0411701-16D | |
| Mercury | 0,01 | mg/kg | 2042-0402501-16D | |
| Nickel | 1 | mg/kg | 2042-0411701-16D |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| State of matter | 20 °C | liquid | ||
| Density | 15 °C | 1.54 | g/cm³ | DIN 51757 |
| Density | 20 °C | 1.52 | g/cm³ | DIN 51757 |
| Density | 50 °C | 1.505 | g/cm³ | DIN 51757 |
| Boiling point | 1,013 hPa | 143.00 | °C | |
| Melting point | 12.00 | °C | ||
| Melting point | 12.00 | °C | ||
| pH-value | 20 °C | > 14 | ||
| pH-value | 14 | |||
| Viscosity, dynamic | 20 °C | 85 | mPa·s | |
| Color | colourless | |||
| Odor | odourless | |||
| Odor | Odorless |
Caustic soda solution is a strongly alkaline, caustic, water-clear, odorless liquid which is infinitely miscible with water.
When open to the air, it becomes cloudy due to absorption of carbon dioxide with formation of sodium carbonate.
| NaOH % | Density g/l (20°C) | Boiling Point °C | Solidification °C |
|---|---|---|---|
| 10 | 1.109 | 103 | -10 |
| 20 | 1.219 | 108 | -34 |
| 30 | 1.328 | 116 | +1 |
| 32 | 1.349 | 120 | +7 |
| 33 | 1.359 | 119 | +8 |
| 40 | 1.430 | 128 | +15 |
| 45 | 1.478 | 135 | +7 |
| 50 | 1.525 | 143 | +12 |
It should be noted that 50 % caustic soda solution already becomes viscous at about 15 °C and can only be pumped with difficulty.
The average values of the dynamic viscosities (mPa*s) of 10 to 50 % caustic soda solution at temperatures of 20 - 80 °C are shown in the following table:
| NaOH (%) | 20 °C | 40 °C | 60 °C | 80 °C |
|---|---|---|---|---|
| 10 | 1.9 | 1.2 | 0.83 | 0.65 |
| 20 | 4.2 | 2.3 | 1.5 | 1.0 |
| 30 | 13 | 6.0 | 3.1 | 1.9 |
| 32 | 17 | 7.0 | 3.7 | 2.2 |
| 33 | 18 | 7.5 | 3.8 | 2.3 |
| 40 | 37 | 12.0 | 6.1 | 3.4 |
| 45 | 56 | 17.0 | 7.8 | 4.4 |
| 50 | 85 | 23.0 | 9.7 |
5.4 |
Health and Safety Information
Disclaimer
Responsibility and Liability
The use of Covestro products, technical assistance, and information (regardless of how provided) is outside Covestro’s control and is solely the responsibility of the customer. The customer must conduct adequate testing to determine the suitability of products for its intended use, including but not limited to technical, health, safety, and environmental aspects. Unless otherwise agreed in writing, all products are sold exclusively under Covestro’s standard conditions of sale, which prevail in case of conflict and are available upon request.
The terms and conditions of sale and delivery are available via the following link:
https://order.covestro.com/covestrostorefront/saleConditions
All information is provided “as is” without warranties, express or implied, including merchantability or fitness for a particular purpose, and is subject to change without notice. To the maximum extent permitted by law, Covestro disclaims, and the customer assumes all liability for losses, damages, or claims arising out of use of Covestro products, technical assistance, or information. Any statement or recommendation not expressly contained in Covestro documentation is unauthorized and shall not bind Covestro. Nothing herein shall be construed as encouraging or recommending the use of any product in conflict with any claim of any patent. No license is implied or in fact granted under the claims of any patent.
Restrictions on Regulated Applications
This product is not intended for use in regulated applications such as agriculture, cosmetics, drinking water contact, food contact, medical products (e.g., medical devices), toys, or similar uses subject to specific regulatory requirements. Prior written approval from Covestro is required before this product may be used in any regulated application. The customer is solely responsible for ensuring compliance with all applicable laws and determining product suitability. Covestro disclaims all liability and warranties for unauthorized regulated uses.
Typical Value
The values provided are typical only and do not represent binding specifications. Unless expressly confirmed in a written contract, these values are not part of the contractual quality agreement and must not be relied upon as a warranty or guarantee of product performance.
Sample
Samples provided by Covestro are intended solely for evaluation and testing purposes by the customer and may not be used in commercial applications, resold, transferred to third parties (except qualified testing service providers acting on behalf of the customer), reverse engineered, modified, or used in any manner not explicitly authorized in writing by Covestro. Samples are provided ‘as-is’ without any warranties, express or implied, including fitness for a particular purpose. Customers are solely responsible for ensuring safe handling, regulatory compliance, and suitability of the material for their intended evaluations. Covestro disclaims all liability for damages or losses arising from the use of samples.
Contact Information
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