Stainless Steel Safety Overview
The following safety overview applies to stainless steel in sheet and coil formats from which Longshen supplies its stainless steel products:
- Under REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) stainless steel products are considered to be ‘Articles’ and therefore do not require a safety data sheet.
- Stainless steel is harmless in solid form and is non-hazardous. For this reason it is utilised where safety and hygiene are of key importance such as for medical, food preparation and drinking water applications.
- Stainless steel is odourless.
- Solid stainless steel is insoluble and does not leach into soil or ground water. Therefore, ‘Articles’ produced from solid stainless steel are not considered to be an ecological hazard.
- Stainless steel is 100% recyclable and its recycled content is as high as 85% from some European mill sources and consequently has limited impact when disposed of.
- A low percentage of stainless steel is not recycled and such materials are classified as a non-hazardous waste.
- Solid state stainless steels are stable and non-reactive under normal ambient atmospheric conditions as all alloy elements are firmly bound into the metallic structure. Due to this bonding and the presence of a passive and naturally forming oxide film, the release of the alloying constituents is negligible when used appropriately.
- Solid stainless steel does not contain Cr(vi) compounds.
- There are no occupational exposure limits for solid stainless steel.
Note: During the additional processing of stainless steel through cutting, grinding or welding, dust and fumes may be generated and if inhaled over an extended time frame, it may affect your health. Of course, the process of welding should be performed with appropriate PPE; if more information is required on this or on stainless steel dust and alloying elements, please refer to the mill safety information sheet.
Stainless Steel Fire Performance
Below is a brief overview of the suitability and performance of stainless steel in fire situations according to its material properties.
Longshen is a manufacturer of stainless steel finishes supplied in flat sheets, and is not involved in the fabrication or installation of stainless steel cladding. On that basis, this document addresses only the basics of stainless steel in its solid form.
Stainless steel is not ignitable and also does not assist in the propagation of fires by flame spread. The surface of stainless steel is normally inert and stable in oxidising conditions, such as those found in most flames and heat sources.
Furthermore, and as indicated below, stainless steel has a relatively high melting point and as a metal outperforms the common metal alternatives used in cladding applications in this respect.
| Fire Test | |
| Stainless Steels | Melting Point °C |
| 304 (1.4301) | 1400-1450 |
| 316 (1.4404) | 1375-1400 |
| Other Metals | |
| Aluminium | 659 |
| Aluminium Alloy | 463-671 |
| Copper | 1085 |
| Zinc | 419 |
| Brass | 927 |
For fire performance of specific cladding panels and systems, the cladding contractor should be contacted.
Cleaning Guidelines for Stainless Steel
For stainless steel components where an attractive appearance is particularly important such as building cladding, shop entrances and signs; regular cleaning is advisable in order to maintain the prime condition of the material.
Washing also removes dirt and impurities that may cause corrosion to stainless steel and discolouration of the metal surface if left in place too long. The more polluted the environment, the more often such washing of the stainless steel should be carried out.
The intervals between washing should be determined from the local environment and from experience, but generally the following guidelines should be observed.
| Environment | Recommended Washing Intervals | |
| Type 304 | Type 316 | |
| Clean inland location | 3-6 months | 6-12 months |
| Polluted urban area / internal location / industrial | Unsuitable | 3-6 months |
| Coastal location / Marine | Unsuitable | 3-6 months |
Washing of stainless steel is best carried out with soap or a mild detergent and warm water followed by rinsing with clean cold water.
The appearance of the stainless-steel surface can be improved further if the washed surface is wiped dry.
Stainless steel is easy to clean. Washing with soap or mild detergent and warm water followed by a clear water rinse is usually adequate for domestic and architectural purposes.
Where stainless steel has become extremely dirty with signs of surface discolouration, alternative methods of cleaning can be used as outlined below.
In environments where there is heavy use of aggressive contaminants such as chemicals, salt or de-icing salts, then high frequency cleaning every second month is recommended.
| Surface Condition | Suggested Cleaning Method | Comments |
| Light soiling | Soap, detergent or dilute (1%) ammonia solution in warm clean water. Apply with a clean sponge, soft cloth or soft-fibre brush then rinse in clean water and dry. | Proprietary traffic film removers (TFR) as used for cleaning cars show good results and are easily removed to leave a streak free finish. |
| Fingerprints | Detergent and warm water. Alternatively, clear liquid bleach-free window cleaners. | Proprietary spray-applied bleach free window cleaners. |
| Stubborn spots, stains and light discolouration. Water marking. Light rust staining. | 5% phosphoric acid solution then rinse in clean water and dry. | Proprietary cleaning products are available e.g. Vecom “Vecinox” stainless steel cleaner. |
| Heavier staining or rust spots | 10% phosphoric acid solution, followed by ammonia and water rinses. | Proprietary cleaning products are available from a number of companies e.g. Vecom “Vecinox” stain remover. |
| Adherent hard water scales and mortar/cement splashes | 10-15 volume % solution of phosphoric acid. Use warm, neutralise with dilute ammonia solution, rinse with clean water and dry. | Proprietary formulations available from a number of companies |
| Paint or graffiti | AAlkaline or solvent paint strippers, depending upon paint type. Use a soft nylon brush on patterned surfaces. | Proprietary products are available from a number of companies e.g. TRINAR. |
Notes
- When cleaning a surface with any chemical preparation, a trial should be undertaken on a small, unobtrusive hidden or non-critical area of the surface, in order to check that the resulting finish still matches with the original.
- The products referenced in this documentation are understood to be suitable for stainless steels. However, no endorsement of the products or their manufacturers is implied. It is acknowledged that other manufacturing companies may provide products of equal or better quality.
- Cleaning agents should be approved for use under the relevant national environmental regulations and, in addition, prepared and used in accordance with the manufacturers’ or suppliers’ instructions. Solvents should not be used in enclosed areas.
- To avoid water marks, use clean rinsing water, such as reasonable quality potable (tap) water. Drying marks may be avoided using an air blower or wiping with clean disposable wipes.
- Chloride-containing solutions, including hydrochloric acid-based cleaning agents and hypochlorite bleaches can cause unacceptable surface staining and pitting and should not be used in contact with stainless steels. Under no circumstances should concentrated bleaches come into contact with decorative stainless steel surfaces. Hydrochloric acid-based solutions, such as building mortar removal solutions, must not come into contact with stainless steel. Hypochlorite containing bleaches must be used in the dilutions suggested in the manufacturers’ instructions and contact times kept to a minimum. Thorough rinsing after use is important. A frequent cause of staining and micro pitting of stainless steel is a direct result from splashing of undiluted bleach solutions and mortar cleaners.
Longshen Metals cannot accept responsibility for any problems or damages arising as a result of these suggested methods of cleaning.
Cautions
- Cleaning agents containing bleach should not be left in contact with stainless steel. This includes many of the ‘trigger-dispenser’ cleaning products. If bleach is necessary it should be used only in the strengths prescribed by the manufacturer and never soaked for longer than 15 minutes, after which the stainless steel surface should be thoroughly rinsed with clean water.
- Harsh abrasives and scouring materials should not be used for cleaning stainless steel as they will leave scratch marks on the surface and damage the appearance of the article. Likewise, do not use wire brushes, scrapers or contaminated scouring pads.
- If the article has a directional polished grain, any cleaning with abrasives should be carried out along the direction of the grain and not across it.
- After use, always remove wet cleaning aids (such as cloths, pads, containers) from the surface, to avoid formation of water marks/stains.
- Strong acids such as sulphuric and hydrochloric are very corrosive and should not be allowed to come into contact with stainless steel.
Protective Tape Residue
After the removal of protective tape from supplied materials, it is possible that adhesive residue will be left behind. Fortunately, this does not happen often but it is possible.
In such circumstances, the general advice from Longshen’s protective tape suppliers, Nitto Adhesive Tapes, is to clean away the adhesive residue using Acetone or a similar product with a soft cloth and afterwards to rinse the affected area with water.
It is always recommended that you first test your cleaning method on a non-visible area of the material in case there is an adverse effect to the material or its surface.