This page contains machine-translated content. For safety-relevant sections, the German original text is also shown and remains authoritative.

Cleaning graffiti off the tables (do not try this at home! EtOH)

ID: 69310  |  No.: 320  |  Institut für Chemieinformation

School experiment from Year 5 onwards

Category: Working techniques

Note: Transferring to your DEGINTU account for risk assessment and its documentation is recommended!
Procedure

Ethanol as a surface cleaning agent.

Description of an incident involving the widespread spillage of ethanol whilst cleaning tables: The low flash point (12 °C) of highly volatile ethanol means that, when applied over a large area, a flammable vapour-air mixture forms rapidly. Even a small ignition source, such as an electrical contact (computers, light switches) or an electrostatic discharge (textiles), can ignite this mixture and trigger a catastrophic fire or deflagration.

Source: http://halbmikrotechnik.de/service/chemie/sicherheit/urteil1.htm

Furthermore, ethanol vapours can cause chronic inflammation of the brain and nerves, which are recognised as occupational diseases. Ethanol is therefore listed under BK 1317.

Occupational disease BK 1317 – Polyneuropathy or encephalopathy caused by organic solvents or mixtures thereof (BK Report 1/2018): http://publikationen.dguv.de/dguv/udt_dguv_main.aspx?FDOCUID=26950

It is therefore essential to use less hazardous cleaning agents for this task.

Description of learning environments and clusters which are available as multi-purpose rooms instead of subject-specific classrooms (page 20) and are not suitable for teaching involving hazardous substances:

https://digital.zlb.de/viewer/api/v1/records/15879414/files/images/MUR_MJG_Schulumbau.pdf/full.pdf

Equipment & materials

Paper towels,

Solvent for Spirit thermal printers (technical ethanol)

Hazardous substances
Name Formula CAS no. H-statements P-statements Pictograms
Ethanol C₂H₅OH 64-17-5
H225 – Liquid and vapour are highly flammable.
German original: Flüssigkeit und Dampf leicht entzündbar.
H319 – Causes serious eye irritation.
German original: Verursacht schwere Augenreizung.
P210 – Keep away from heat, hot surfaces, sparks, open flames and other sources of ignition. Do not smoke.
German original: Von Hitze, heißen Oberflächen, Funken, offenen Flammen und anderen Zündquellen fernhalten. Nicht rauchen.
P233 – Keep the container tightly closed.
German original: Behälter dicht verschlossen halten.
P240 – Earth the container and the equipment to be filled.
German original: Behälter und zu befüllende Anlage erden.
P241 – Use explosion-proof electrical equipment / ventilation systems / lighting /...
German original: Explosionsgeschützte elektrische Betriebsmittel / Lüftungsanlagen / Beleuchtung /... verwenden.
P242 – Use only non-sparking tools.
German original: Nur funkenfreies Werkzeug verwenden.
P305+P351+P338 – IF IN EYES: Rinse gently with water for several minutes. Remove any contact lenses if possible. Continue rinsing.
German original: BEI KONTAKT MIT DEN AUGEN: Einige Minuten lang behutsam mit Wasser spülen. Vorhandene Kontaktlinsennach Möglichkeit entfernen. Weiter spülen.
GHS02, GHS07

H/P statements: machine translation, with the German original below (authoritative). Name, formula, CAS no. and pictograms are not translated.

Personal protective equipment
  • Safety goggles must be worn.
    German original
    Eine Gestellschutzbrille ist zu tragen.
  • Disposable nitrile gloves are used as splash protection.
    German original
    Als Spritzschutz dienen Nitril-Einmalhandschuhe.
⚠ Hazards
  • through eye contact
    German original
    durch Augenkontakt
  • Fire hazard
    German original
    Brandgefahr
  • Risk of explosion
    German original
    Explosionsgefahr
⚠ Further hazards and notes
  • Start-up fires
    Fight small fires with a fire extinguisher. Pupils must keep a safe distance. If the fire cannot be extinguished immediately, leave the room straight away and alert the fire brigade and the school management. Fight fires involving people immediately using a hand-held hose or, if necessary, a fire extinguisher – every second counts!
    German original
    Entstehungsbrände mit Feuerlöscher bekämpfen. Schülerinnen und Schüler halten sicheren Abstand. Können diese nicht sofort gelöscht werden, Raum unverzüglich verlassen und Feuerwehr sowie Schulleitung alarmieren. Personenbrände mit Handbrause oder ggf. Feuerlöscher unverzüglich bekämpfen, hier zählt jede Sekunde!
  • Major leaks
    In the event of an accident, leave the room immediately and alert the fire brigade (tel. 112) and the school management; small leaks can be mopped up using chemical absorbents, but appropriate personal protective equipment must be worn; pupils must keep a safe distance.
    German original
    Im Havariefall Raum unverzüglich verlassen und Feuerwehr (Telefon 112) sowie Schulleitung alarmieren, kleine Leckagen können mit Chemikalienbinder aufgenommen werden, hierbei ist geeigneter Selbstschutz erforderlich, Schülerinnen und Schüler halten sicheren Abstand.
Substitution Substitution 1
The substitution of hazardous substances, as well as their forms of use and methods of application, has been assessed. This experiment is essential for teaching key learning outcomes and may be carried out provided that the restrictions set out in the experiment protocol are observed and the protective measures specified therein are implemented.
There are no known hazardous properties of the substances or other risks that would, in principle, preclude the experiment from being carried out by pupils or teachers. The list of substances in DGUV Information 213-098 at degintu.dguv.de has been taken into account.

The substitution assessment is flawed because:

  • cleaning work can be carried out without the use of hazardous substances,
  • hazardous substances that are highly volatile or highly flammable should, as a general rule, not be handled indoors outside of suitable specialist rooms, and
  • as a general rule, ventilation is insufficient for the open handling of highly volatile or highly flammable hazardous substances if it is carried out in accordance with the 20/5/20 rule or, as shown in the symbol, is to take place via a window that is only partially open.

Suitable specialist rooms must comply with the requirements set out in the statement by the GDCh’s Chemistry Education Section:

https://www.gdch.de/fileadmin/downloads/Netzwerk_und_Strukturen/Fachgruppen/Chemieunterricht/PDF/Stellungnahme_FGCU_Fachra__ume_2018.pdf

Literature

Description: Cleaning graffiti off tables (2026) Klemeyer, H. DOI: 10.5281/zenodo.22832242