The HZ-4 is a hazardous material cleanup automaton — a tracked platform the size of a small car with a sealed, pressurized chassis and a pair of articulated arms equipped with containment tools: vacuum extraction nozzles, chemical neutralization sprayers, sample collection systems, and sealed waste containers rated for biological, chemical, and radiological materials. The HZ-4 enters contaminated environments, identifies the hazardous substance, and performs decontamination procedures autonomously.

Lazarus designed the HZ-4 for environments where human hazmat teams face unacceptable risk — major chemical spills, radiological incidents, and biological contamination events where the nature of the hazard is unknown. The HZ-4's sealed chassis contains its own atmospheric supply and can operate in environments ranging from nerve agent concentration to moderate radiation exposure for up to six hours. Its sample collection system can identify over eight thousand hazardous compounds through onboard spectroscopic analysis, allowing it to determine appropriate neutralization protocols without waiting for laboratory results.

The HZ-4 is expensive — Φ280,000 per unit — and GLMZ operates only forty of them, distributed across emergency response stations. Lazarus maintains them under a service contract that gives the company access to all contamination data collected by the units, which feeds into Lazarus's pharmaceutical and bioweapon research divisions. The machine that cleans up chemical spills is also the machine that tells Lazarus what chemicals are being spilled, where, and in what quantities. The data is worth more than the cleanup service.