User codes for chemicals
| Code | Recommended users in an "average" class |
|---|---|
| K-12 | Students in Kindergarten (Foundation) to Year 12, under teacher supervision. |
| 7-12 | Students in Years 7-12, under teacher supervision. |
| 11-12 | Students in Years 11-12, under teacher supervision. |
| Tch | Teachers, for use in demonstrations. |
| N | Not recommended; if used, then only by skilled teachers. |
| X | Banned in many school systems; if used, then only by highly skilled teachers. |
Although optional, RiskAssess recommends the use of user codes in all schools.
User codes recommended by RiskAssess are suitable for an "average" class.
Prior to commencing every experiment, a risk assessment should be carried out taking into account "all relevant matters", including
- facilities available
- behaviour of the class
- students and staff with allergies
- students with special needs
- degree of supervision, and
- skill level of the teacher.
A teacher may decide that chemicals with more or less potential hazards than those recommended for the "average" class should be used by students. A teacher should also check if any of the chemicals are banned or not recommended by their own school authority, prior to use.
In some class situations, e.g. with poorly-behaved classes or with students having allergies or special needs, the teacher should consider whether chemical usage should be more restricted than that recommended in RiskAssess for the "average" class.
With a well-behaved class and good facilities (e.g. fume cupboard), the teacher could consider whether chemical usage may be expanded to include substances that pose greater hazards than recommended for the "average" class.
Codes for pure substances are based on the latest GHS data from ECHA. Solution information is based on the application of the GHS rules for mixtures (with water as an inert diluent), where specific data are not available.
The user codes recommended by RiskAssess are based on the GHS classifications of chemicals, using ECHA data. This means that some chemicals used in past experiments may be more hazardous than previously thought. In these cases, school staff should carefully consider alternatives. If the risk level cannot be reduced to ”low risk" for an experiment when control measures are in place, the teacher should use less hazardous chemicals or substitute a different experiment that provides the same learning benefits for students.