The crystallisation of ice from a 1 wt% sodium sulphate solution was investigated at different cooling rates and solution volumes in order to determine the metastable zone (MSZ) for the system. The results from this study showed that there was a large variation in nucleation temperatures, thus confirming the stochastic nature of nucleation. The results also showed that the width of the MSZ was independent of solution volumes greater than 250 mL. The nucleation temperatures for smaller solution volumes showed a greater spread than the larger solution volumes. The smallest MSZW for a 1 wt% sodium sulphate solution (1.8 mL volume) was 2.6 degrees C for a cooling rate of 2 degrees C/h, 2.8 degrees C for a cooling rate of 4 degrees C/h and 4.8 degrees C for a cooling rate of 8 degrees C/h. (C) 2011 Elsevier Ltd. All rights reserved.