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Safety Protocol 001: Post-Processing Safety — Washing, Curing, and Finishing

Protocol ID: U2M4-SAFE-001 Context: Safety procedures during resin print post-processing including IPA washing, UV curing, support removal, sanding, and surface finishing Hazard Level: Medium (flammable solvents, UV radiation, sharp tools, dust generation) Target Audience: All students

Potential Hazards

  • IPA flammability: Flash point 12°C — vapors ignitable at room temperature. Concentrated vapors in enclosed wash stations are an explosion risk near ignition sources.
  • Uncured resin contact: Green-state parts and wash IPA contain uncured resin — skin sensitizer until fully post-cured.
  • UV radiation: Post-curing stations emit 405nm UV light at high intensity. Eye exposure causes photokeratitis; skin exposure causes irritation.
  • Sharp tools: Flush cutters, hobby knives, and scrapers create cut and puncture hazards during support removal.
  • Resin dust: Sanding cured resin generates fine particulate. While fully cured resin is inert, inhaling fine dust of any material irritates the respiratory system.
  • Spray primer/coating fumes: Aerosol propellants and paint solvents are flammable and irritating to respiratory system.
  • Thermal hazard: Parts exiting UV curing stations may be warm (40-60°C). Curing station heating elements can cause burns.

Required Precautions & Procedures

IPA Washing Safety

  • Keep IPA containers sealed when not actively washing
  • Position the wash station at least 1 meter from any heat source (printer, curing station, hot plate)
  • Use only in a ventilated area — IPA vapors accumulate at bench level
  • Do not use IPA near open flames, hot surfaces, or electrical spark sources
  • If IPA spills: ventilate area, absorb with paper towels, do NOT use water
  • Maximum open-container IPA volume at any workstation: 500mL
  • Store bulk IPA in a fire-rated flammable storage cabinet

UV Post-Curing Safety

  • Close the curing station cover before starting the UV cycle
  • Never look directly at the UV LED array while operating
  • Wear UV-blocking safety glasses when opening the curing station or inspecting parts mid-cycle
  • Do not reach into the curing station while UV is active
  • Allow parts to cool for 2 minutes after curing before handling (especially if heat-cured at 60°C)
  • Keep the curing station in a location where passersby are not exposed to UV leakage

Support Removal Safety

  • Wear safety glasses — support tips and fragments can snap off and fly unpredictably
  • Use flush cutters: keep fingers behind the cutting edge, cut AWAY from your body
  • Hobby knife: use a cutting mat underneath, cut away from your body, retract blade when setting down
  • If working on a part still in green state: wear nitrile gloves (surface may still have trace uncured resin)
  • Dispose of cut support fragments — do not leave them loose on the workbench

Sanding Safety

  • Wear safety glasses to prevent dust entering eyes
  • Wear a dust mask (N95 or better) when dry sanding resin parts
  • Wet sanding is preferred — it reduces airborne dust significantly
  • Work in a ventilated area or over a damp paper towel to capture dust
  • Wash hands after sanding to remove all particulate
  • Do not blow dust off parts with compressed air without wearing eye and respiratory protection

Spray Primer/Coating Safety

  • Apply spray coatings ONLY in a ventilated area or dedicated spray booth
  • Never apply near open flames or ignition sources (propellant is flammable)
  • Wear a respirator with organic vapor cartridges for extended spray sessions
  • Keep distance of 20-25cm between spray nozzle and part for even application
  • Allow adequate drying time in the ventilated area before moving the part

Emergency Response

If IPA ignites during washing: 1. If small container fire: cover with a metal lid or fire blanket to smother 2. If spreading: use Class B fire extinguisher (CO2 or dry chemical) 3. Do NOT use water on IPA fires 4. Evacuate if fire is not immediately controlled 5. Call 911

If UV light exposure to unprotected eyes: 1. Move away from the UV source immediately 2. Symptoms may be delayed 6-12 hours (pain, tearing, light sensitivity) 3. If symptoms develop: seek medical attention 4. Apply cold compress for comfort; do NOT rub eyes

If cut by hobby knife or flush cutters: 1. Apply direct pressure with a clean paper towel 2. If the cut was on a surface with uncured resin: flush wound thoroughly with soap and water 3. Apply bandage 4. For deep cuts or cuts that won't stop bleeding: seek medical attention 5. Report the injury to the lab supervisor

PPE Requirements

Equipment When Required Specification
Nitrile gloves IPA washing, green-state handling, spot filler application 5+ mil thickness
UV-blocking safety glasses UV curing station operation, UV flashlight use Polycarbonate, 385-405nm blocking
Safety glasses Support removal, sanding, compressed air use ANSI Z87.1 rated
Dust mask Dry sanding resin parts N95 minimum
Respirator Spray primer/coating application Half-face with organic vapor cartridges

Last Updated: 2026-03-19