The optimised PAN indicator contains:
Component Quantity
PAN 0.1 g
methanol 40.0 ml
n-propanol 40.0 ml
mono-ethylene glycol 10.0 ml
distilled or deionised water 10.0 ml
To make the indicator:
1. It is strongly recommended that preparation of the indicator is carried out in a fume cupboard.
2. Place the methanol in a suitable container, add the PAN and stir.
3. Dissolution of the PAN can take some time. Dissolution can be accelerated by warming gently. Avoid excessive heat because the flash point of methanol is only 11 °C. Ensure that there are no ignition sources when warming or preparing solutions.
4. When fully dissolved, allow to cool.
5. Then add the n-propanol, mono-ethylene glycol and water. Mix thoroughly by stirring.
6. Store in tightly closed container.
Note: that this indicator formulation contains organic solvents and, consequently, may have to be stored in fire resistant cupboards according to type and size of container.
The shelf life of the indicator is anticipated to be at least one year if it is stored correctly. Since only small quantities are required for assessments, it is recommended that no more than 200 ml of indicator is made at any one time.