Chemishield — Chemical Waste Management Platform

Chemishield is a web portal for chemical waste disposal safety, built to answer a critical question before chemicals are combined or disposed of: are these substances safe to mix?

The compatibility engine works against a chemical compatibility matrix dataset — the same kind of data underpinning industry-standard Safety Data Sheets (SDS/MSDS) — where each chemical pair carries a defined compatibility status (compatible, incompatible, or conditional). These classifications are grounded in established chemical safety standards used by laboratories, waste disposal facilities, and safety officers — not developer-defined rules.

Built with a React frontend, Node.js backend, and a PostgreSQL database managed via Sequelize ORM, the system catalogued 250 chemicals at launch.

Combinatorial data modelling: With 250 chemicals, the compatibility matrix covers approximately 31,000 unique pairwise relationships. Designing a PostgreSQL schema via Sequelize that could store, query, and return correct compatibility verdicts for any arbitrary combination of chemicals — efficiently and without ambiguity — was a core data modelling challenge.

Translating domain knowledge into software: The compatibility data originated from chemical safety standards expressed in the language of chemistry and regulation, not software. Mapping that into a queryable relational model required close collaboration with domain knowledge holders and careful interpretation of safety classification logic.

High-stakes UI clarity: The frontend had to present compatibility results unambiguously. A missed incompatibility warning could have real-world safety consequences, so safe/unsafe/conditional distinctions had to be immediately legible — not buried in data tables.

Catalogued 250 chemicals covering ~31,000 pairwise compatibility relationships, queryable in real time through a web interface.

Replaced manual consultation of physical SDS charts with an instant, structured compatibility check accessible to lab staff and safety personnel.

Delivered a full-stack portal (React + Node.js + PostgreSQL/Sequelize) grounded in industry chemical safety standards rather than arbitrary application logic.