Standard industrial grade: 9,000 hours (about 12 months for 24‑hour continuous operation).
High‑end long‑life type: 12,000–16,000 hours (1.5–2 years).
Note: Visible brightness does not indicate effective UV intensity. The 185 nm UV output decays over time. Lamps generally need replacement every 1 year to maintain stable TOC removal efficiency.