Glass-transition related stickiness or cohesiveness has been a topic of significant scientific and practical interest in the last decade. The concept is very important in both food and pharmaceutical product developments. It is more appropriate to consider its development as a rate process but the time-response has been very difficult to measure accurately until lately. Here, the classical rate law for chemical reaction has been tested for its fitness in correlating the time-response of cohesion or stickiness developed in packed amorphous particles during temperature/humidity treatments. The rate law has been benchmarked against the T - T(g) dependent rate function established in the previous studies [Foster, K. D., Bronlund, J. E., & Paterson, A. H. J. Glass transition related cohesion of amorphous sugar particles. Journal of Food Engineering, in press.], using the original data sets for amorphous sucrose particles measured by Foster. It has been shown that the classical rate law is an excellent approach to accurately account for the process. (c) 2006 Elsevier Ltd. All rights reserved.