Safety Protocol 001: Material-Specific Hazards in Plasma Cutting

Protocol ID: U5M2-SAFE-001 Context: Safety procedures for managing hazardous fumes, coatings, and material-specific risks during plasma cutting operations Hazard Level: High to Very High — Material-specific fumes can cause acute illness, chronic disease, and cancer

Potential Hazards

Toxic Fume Hazards by Material

• Galvanized steel (zinc coating): Zinc oxide fumes cause metal fume fever — flu-like symptoms appearing 4-12 hours after exposure. Repeated exposure can cause chronic respiratory issues
• Stainless steel (chromium/nickel): Hexavalent chromium (Cr VI) is an OSHA-regulated carcinogen (PEL: 5 μg/m³). Nickel fumes are also a respiratory sensitizer and suspected carcinogen
• Painted/coated metals: Lead-based paint (pre-1978 buildings/structures), cadmium plating, and chromate primers produce extremely toxic fumes
• Brass/bronze: Copper and zinc fumes — zinc causes metal fume fever, copper causes respiratory irritation
• Aluminum: Aluminum oxide fumes are a respiratory irritant; less toxic than steel fumes but still require protection

Prohibited Materials

The following materials must NEVER be plasma cut in a standard makerspace: - Beryllium copper: Beryllium is an extreme carcinogen (OSHA PEL: 0.2 μg/m³) — requires specialized containment - Cadmium-plated metals: Cadmium oxide fumes are extremely toxic and carcinogenic - Magnesium: Extreme fire hazard — burns at 5,610°F, cannot be extinguished with water - Titanium (without proper setup): Fire risk, toxic fumes without inert atmosphere - PVC or plastic-coated metals: Chlorine gas production — immediately dangerous to life

Thermal Hazards

• Warping: Thin sheet metal warps from thermal stress, creating handling hazards (sharp warped edges)
• Retained heat: Different metals retain heat at different rates — aluminum cools faster but has higher thermal conductivity, creating larger hot zones
• Scale and spatter: Molten metal spatter varies by material — stainless and aluminum produce more spatter than mild steel

Required Precautions & Procedures

Before Cutting Any Metal

1. Positively identify the material — use magnet test, spark test, visual inspection, or material certification (mill test report)
2. Identify any coatings — galvanization, paint, plating, anodizing, powder coating
3. Check the prohibited materials list — if uncertain about material composition, DO NOT CUT until confirmed
4. Verify ventilation capacity — enhanced ventilation required for stainless steel and galvanized steel
5. Select appropriate respiratory protection based on material (see PPE table)

Galvanized Steel Protocol

1. If possible, grind off the zinc coating within 1" of all cut lines before plasma cutting
2. If coating cannot be removed: maximize ventilation, use P100 + OV respirator, minimize cutting duration
3. Monitor all operators for metal fume fever symptoms for 12 hours after exposure
4. Post warning signs: "GALVANIZED STEEL CUTTING IN PROGRESS — ENHANCED VENTILATION REQUIRED"

Stainless Steel Protocol

1. Activate maximum fume extraction — local exhaust at the point of cutting (downdraft table or fume arm)
2. All personnel in the cutting area must wear P100 + OV half-face respirator minimum
3. Limit continuous cutting duration to 30 minutes, then allow 15 minutes for fume clearance
4. Keep an exposure log — document all stainless steel cutting sessions for OSHA compliance

Coated/Unknown Metal Protocol

1. If material identity or coating is unknown: DO NOT CUT
2. Request a material safety data sheet (SDS) from the material supplier
3. If coating is visible but unidentified, send a sample for testing or grind to bare metal
4. Assume worst-case respiratory protection (supplied-air or P100/OV) for any unknown material

Emergency Response

1. Fume inhalation symptoms (cough, dizziness, metallic taste, nausea): Move person to fresh air immediately. Remove contaminated clothing. Seek medical attention. Provide responders with material identification
2. Metal fume fever symptoms (delayed 4-12 hours: fever, chills, body aches, headache): Seek medical attention. Hydrate. Rest. Symptoms typically resolve in 24-48 hours but can recur with repeated exposure
3. Severe respiratory distress (difficulty breathing, chest tightness): Call 911. Administer supplemental oxygen if available and trained. Do not give fluids to an unconscious person
4. Skin contact with hot coated metal: Cool with running water 20 minutes. Seek medical attention if coating burns into skin (chemical + thermal burn)
5. Document all exposures for medical and regulatory records

PPE Requirements

Material Being Cut	Minimum Respiratory Protection	Additional PPE
Mild steel (uncoated)	N95 dust mask	Standard plasma PPE
Stainless steel	P100 + OV half-face respirator	Enhanced ventilation required
Galvanized steel	P100 + OV half-face respirator	Enhanced ventilation, grind coating if possible
Aluminum (uncoated)	N95 or P100 half-face	Standard plasma PPE
Painted metal (unknown paint)	P100 + OV half-face respirator minimum	Supplied air if lead paint suspected
Brass/Bronze	P100 half-face respirator	Enhanced ventilation
Unknown material	DO NOT CUT	Identify material first

Standard Plasma PPE	Specification	Required When
Welding helmet	Shade 8-12	All cutting
FR clothing	ASTM F1506 rated	All cutting
Leather gloves	14" gauntlet	All cutting and handling
Leather boots	Steel/composite toe, 8"+	Always in cutting area
Hearing protection	NRR 25+	All cutting

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Last Updated: 2026-03-19