Effect of pre-lab information on chemical spillage on volume subsequently spilled: a randomized controlled trial, meta-analysis and comparison with improvement through repetition

Understanding methods to improve the safe handling of hazardous chemicals is important to improve laboratory safety. In this work, a simple online resource with contextual safety information on chemical spillage was developed and provided to year 1 undergraduate students prior to undertaking a laboratory practical. The effects of this safety information on amount of chemical subsequently spilled was examined using a randomized controlled trial, with a median effect size for the reduction in spillage of 37%, in comparison with those not receiving this information (95% confidence interval: −18% to 68% reduction and p = 0.14). To improve the robustness of this finding, a pretrial protocol for this randomized controlled trial was published on an open platform in a frozen document prior to data collection commencing. The effects of this pre-experiment, nonindividualized safety information was combined, using meta-analysis methodology, with results from a previous study which provided safety information postexperiment based on spillage by individual students; the effect of contextual safety information on chemical spillage gave a median reduction in spillage of 50% (95% confidence interval of 0% to 71% reduction, and p = 0.034). Any improvement through repeating the experiment was also investigated with spillage reduced by a median of 61% (95% confidence interval of 52% to 72% reduction, and p = 0.012). These three methods for reducing chemical spillage are compared using an implementation science perspective, highlighting that for the three methods discussed there is the trade-off in that the higher the evidence of benefit, the lower the ease, and hence likelihood, of implementation.