The study investigated the knowledge of postgraduate students in the Biology, Chemistry and Biochemistry departments regarding safety practices, protective measures and risks associated with toxic chemicals in the postgraduate and research laboratories. The study was exploratory and was conducted through administering 83 questionnaires. The results showed that the majority (78%) of the students received training on laboratory safety even though only 34% of them could identify all the warning signs associated with hazardous chemicals. Protective measures practised by students included wearing of buttoned laboratory coats (74%), closed shoes (78%), use of latex gloves (43%), correct use of dustbins for waste disposal (10%) and inspection of warning signs on chemical containers before use (54%), while only 25% of the students used fume cupboards. In case of an emergency, 72% knew what steps to take, whereas 28% were unaware of the steps to take. Students were aware of the potential risks associated with hazardous chemicals in the laboratory and had knowledge on the warning signs on chemicals even though adherence to the safety practices was still a problem. The majority of the participants felt that there was a need for continuous training on laboratory safety and regular reminders through the use of safety charts in laboratories.

Background/Objectives: Pharmaceutical residues in human urine have raised serious concerns about the safe reuse of urine in agriculture. The current study investigates and compares the concentrations of pharmaceuticals in urine samples collected from male patients undergoing active antiretroviral regimens and self-reported “healthy individuals” at a government hospital in Pretoria, South Africa, and determines how the residues changed during three months of ambient storage, which is the usual recommendation before use in agriculture. Methods: The urine samples were collected in a plastic bottle to prevent fecal contamination, and 15 targeted compounds were analyzed using solid-phase extraction and liquid chromatography–mass spectrometry. The linearity ranged from 0.9910 to 0.9999, 75.5% to 99.1% for recovery, and intra-day and inter-day precision were below 6%. The urine from each group was collected into one pooled sample and then analyzed both pre- and post-storage. Results: Thirteen pharmaceuticals were detected in urine from patients on regular medication before storage; in “healthy individuals”, detections rose from eight to twelve after storage. Concentrations in the composite samples after storage were higher for some of the compounds but lower for others, including caffeine, nevirapine, prednisolone and 17α-ethinylestradiol. Metformin was highest overall at 1186.25 µg/L and remained at 806.68 µg/L after storage. The highest concentration for all the pharmaceuticals was reported for metformin, with a value of 1186.25 µg/L, occurring in the group of patients on a regular regimen. There could be a possibility that the rise can be attributed to the hydrolysis of conjugated metabolites during storage; however, no analysis of conjugates was carried out. Conclusions: This study shows the need for appropriate treatment of human urine prior to its reuse as fertilizer and echoes the importance of further research into human exposure pathways and effective pharmaceutical removal strategies.