Glove Box Incident Response: Air Ingress, Solvent Spills, and Power Loss (Triage & Recovery)

Quick Summary (read this first)

• Stabilize pressure (target +3–8 mbar) and protect people first.
• Identify the trigger: O₂ spike, dew-point spike, both, spill, tear, or power loss.
• Log time zero, then follow the scenario SOP below.
• Acceptance to return to service: O₂ back to ≤1–5 ppm, dew point ≤ −60/−40 °C (as your spec) and stable trends for 2–4 h.

1) O₂ Spike (dew point normal) — Likely air ingress

Typical causes: bad antechamber equalization, door cracked open, glove yanked.

Do now

1. Keep circulation ON; hold +5 mbar.
2. Audit last transfer: was the load-lock equalized (±1 mbar) before inner door?
3. Run a short purge (box gas) if O₂ > setpoint for >10 min.
4. Leak check fast: glove beads, door O-rings, feedthrough caps.

Then

• If O₂ decays normally, no regen yet.
• If plateau persists, schedule purifier regeneration (≤5% H₂/N₂) after confirming exhaust and interlocks.

Accept back to service: O₂ ≤ target and falling/stable for 2–4 h.

2) Dew-Point Spike (O₂ flat) — Solvent vapor or wet load

Typical causes: open beakers, wet wipes left inside, hot parts off-gassing.

Do now

1. Close lids; bag solvent-soaked wipes; remove unnecessary sources.
2. Cold/charcoal traps online and at temperature; check trap seals.
3. Maintain circulation; avoid high purge that spreads vapor.

Then

• If DP remains high, run a moderate purge and consider regen only after traps are working (don’t waste purifier media).
• Review tool placement: keep solvent work downstream of sensor intake.

Accept back to service: dew point ≤ target and stable for 2–4 h.

3) Both O₂ and Dew Point Spike — Door fully open or major breach

Do now

1. Secure doors, set +5 mbar, circulation ON.
2. Short purge in increments; watch trends (avoid relief hissing).
3. Inspect gloves, windows, large feedthroughs; replace/retorque as needed.

Then

• If recovery is slow vs historical, regenerate (after verifying exhaust/interlocks).
• Run a pressure-decay leak test once numbers settle.

Accept back: O₂ & DP within spec and flat for 2–4 h; leak rate ≤ your limit (e.g., ≤1×10⁻² mbar·L/s for general R&D).

4) Glove Tear or Port Damage

Do now

1. Clamp/cover the port immediately (cap ring, blank plate, or taped film).
2. Lower setpoint to +3–5 mbar to reduce flow through the defect.
3. Replace the glove: clean bead & O-ring, re-seat evenly; quick leak check.

Then

• Trend O₂/DP for 30–60 min; run a short purge if needed.
• Record part number, thickness, operator for traceability.

Accept back: stable O₂/DP; no pressure creep; glove passes quick pinch test.

5) Solvent Spill Inside the Box

Do now

1. No wiping frenzy. Cover with inert absorbent (pads, dry spill granules).
2. Cold/charcoal traps ON; maintain +5 mbar.
3. Remove saturated absorbent to a sealed can; minimize turbulence.

Then

• Moderate purge in steps if DP/odor remains high.
• Consider regen only after traps and cleanup are complete.

Accept back: DP returns to baseline; odor absent; traps serviced/logged.

6) Power Loss / Controller Crash

Do now

1. Verify pressure relief path; prevent over/under-pressure on restart.
2. After power returns: bring up circulation first, then sensors, then optional purge.
3. Validate sensors (O₂ zero or cross-check; DP dry check) before declaring normal.

Then

• Inspect logs for gaps; annotate event; check UPS coverage for controllers/sensors.

Accept back: control stable; sensors sane; O₂/DP trending to baseline.

Minimal Decision Table

Acceptance Targets (edit to your site)

• Pressure: +3–8 mbar steady (variance ≤1 mbar at idle).
• O₂: ≤ 1–5 ppm and flat/down for 2–4 h.
• Dew point: ≤ −60/−40 °C (per process) and stable.
• Leak rate: ≤ 1×10⁻² mbar·L/s (or your spec).

Post-Incident Prevention (what to change tomorrow)

• Antechamber discipline: three-cycle evac to ≤10 mbar abs, equalize ±1 mbar before inner door.
• Traps: place near sources + in the circulation return; set service cadence.
• Glove care: daily pinch test; keep spares at station; inspect beads & O-rings weekly.
• Logging: 7-day trends for O₂/DP/pressure; note time-to-recover after transfers.
• Training: one laminated 90-second playbook attached to the box.