A Study of Expired Laboratory Chemicals Stockpiles, Storage Facilities and Their Disposal Patterns in Zanzibar’s Secondary Schools

Ochieng O. Anthony, Hemed Shabaan Moh’d & Hassan S. Hassan
https://orcid.org/000-0002-1463-5280 – WEB of Science: AFK-9191-2022
Lecturers, Faculty of Science, Department of Life Sciences, Chemistry Unit, Zanzibar University
Email: d_norbatus@yahoo.com/ hemedsmohd@hotmail.com/ hshassan9@gmail.com

Abstract: The prolonged storage of expired laboratory chemicals in Zanzibar’s secondary schools presents a largely undocumented environmental and public health risk. In many institutions, inventory audits reveal chemicals that expired decades ago remain in storage, where prolonged aging blended with the poorly ventilated and inadequate laboratory conditions have resulted in significant and severe chemical degradation and deterioration of storage containers, thereby increasing occupational and environmental risks. In the absence of clear national policies, standardized disposal guidelines, and functional sewage or waste-treatment systems, schools have accumulated substantial quantities of obsolete reagents. Limited teacher awareness of chemical hazards, coupled with inadequate institutional oversight and resource constraints, has further exacerbated the problem. Using field observations, chemical inventory audits, and semi-structured interviews with chemistry teachers and school administrators, this study documents average percentage of expired and highly degraded chemicals, their physical transformations over time and state of storage conditions, possible health hazard to students and related staff, and possible environmental effects where improper disposal occasionally occurs. The findings reveal significant governance gaps, infrastructural deficiencies, and critical knowledge deficits in chemical waste management. The paper proposes an actionable framework for laboratory infrastructure, safe disposal, emergency risk mitigation, and long-term policy development tailored to resource-constrained educational settings. Addressing these legacy chemicals is essential for safeguarding public health, improving laboratory safety, and aligning Zanzibar’s education system with contemporary environmental standards.