Process Sustainability Comparison
Overview
This table compares the environmental profiles of photographic processes covered in the Sustainable Darkroom series. Use it to understand the relative impacts of different workflows and make informed choices.
Quick Comparison Matrix
| Process |
Silver Concern |
Water Use |
Toxic Chemistry |
Disposal Complexity |
Overall Rating |
| B&W Film Development |
●●○ |
●○○ |
●○○ |
●○○ |
★★★★☆ |
| B&W Printing (RC) |
●●○ |
●○○ |
●○○ |
●○○ |
★★★★☆ |
| B&W Printing (Fibre) |
●●○ |
●●● |
●○○ |
●○○ |
★★★☆☆ |
| C-41 Colour Film |
●●● |
●○○ |
●●○ |
●●○ |
★★★☆☆ |
| RA-4 Colour Printing |
●●● |
●●○ |
●●○ |
●●○ |
★★☆☆☆ |
| Lith Printing |
●●○ |
●●○ |
●○○ |
●○○ |
★★★★☆ |
| Selenium Toning |
●○○ |
●○○ |
●●● |
●●● |
★★☆☆☆ |
| Mordançage |
●○○ |
●○○ |
●●● |
●●● |
★★☆☆☆ |
| Chromoskedasic Sabattier |
●●○ |
●○○ |
●●○ |
●●○ |
★★★☆☆ |
| Cyanotype |
○○○ |
●○○ |
○○○ |
○○○ |
★★★★★ |
| Anthotype |
○○○ |
○○○ |
○○○ |
○○○ |
★★★★★ |
| Van Dyke Brown |
●●○ |
●○○ |
●○○ |
●●○ |
★★★☆☆ |
| Platinum/Palladium |
○○○ |
●○○ |
●○○ |
●○○ |
★★★★☆ |
| Gum Bichromate |
○○○ |
●○○ |
●●● |
●●● |
★☆☆☆☆ |
Key: ○○○ = None/Minimal | ●○○ = Low | ●●○ = Moderate | ●●● = High
Detailed Process Profiles
Standard Black & White Film Development
| Aspect |
Detail |
| Primary concern |
Silver in fixer (0.5–2g per roll ends up dissolved) |
| Secondary concerns |
Developer disposal (minimal—biodegradable) |
| Water use |
~2 litres per roll (Ilford method) |
| Hazardous waste |
Fixer only (silver recovery possible) |
| Key intervention |
Steel wool silver recovery |
| Sustainability rating |
★★★★☆ Highly sustainable with silver recovery |
Standard Black & White Printing
| Aspect |
RC Paper |
Fibre Paper |
| Silver per 8×10 |
~50–100mg |
~100–200mg |
| Silver to fixer |
~60% of paper silver |
~60% of paper silver |
| Water use |
2–4 litres/session |
10–50 litres/session |
| Wash time |
30 seconds – 2 minutes |
20–60 minutes (with HCA: 10–15 min) |
| Key intervention |
Silver recovery |
Silver recovery + HCA + sequential wash |
| Sustainability rating |
★★★★☆ |
★★★☆☆ (water is the issue) |
C-41 Colour Film Development
| Aspect |
Detail |
| Primary concern |
Silver in bleach-fix (1–2g per roll) |
| Secondary concerns |
CD-4 developer (aquatic toxin), EDTA (persistent) |
| Temperature requirement |
38°C ± 0.3°C (energy use) |
| Hazardous waste |
All chemistry except wash water |
| Key intervention |
Separate bleach/fix enables silver recovery; consider lab processing |
| Sustainability rating |
★★★☆☆ Lab processing often more sustainable than home |
RA-4 Colour Printing
| Aspect |
Detail |
| Primary concern |
100% of paper silver goes to waste (vs. ~60% for B&W) |
| Silver per 8×10 |
~50mg (lower coating than B&W, but all becomes waste) |
| Secondary concerns |
CD-3 developer, EDTA in blix |
| Key intervention |
Drum processing (10× less chemistry than trays) |
| Sustainability rating |
★★☆☆☆ Consider scan + commercial RA-4 for efficiency |
Lith Printing
| Aspect |
Detail |
| Primary concern |
Paper waste (low hit rate for “perfect” prints) |
| Chemistry profile |
Actually better than standard B&W—extreme dilution (1+20) means 30–40% less hydroquinone per print |
| Fixer |
Standard—same silver concerns |
| Key intervention |
Accept irreproducibility; don't chase “perfect” |
| Sustainability rating |
★★★★☆ Surprisingly favourable |
Toning Processes
| Toner |
Toxicity |
Disposal |
Notes |
| Selenium |
High (heavy metal) |
Hazardous waste |
Replenish rather than discard; lasts years |
| Sepia/Sulfide |
Low (H₂S during use) |
Drain-safe |
Ventilation critical during use |
| Gold |
Low |
Hazardous waste (prudent) |
Self-limiting due to cost |
| Iron blue |
Very low |
Drain-safe |
Ferric compounds are benign |
Mordançage
| Aspect |
Detail |
| Primary concern |
Copper chloride (aquatic toxin, EPA limit 2.3 μg/L) |
| Key mitigation |
Bleach is reusable indefinitely—amortise over 100+ prints |
| Silver byproduct |
Precipitates as silver chloride; can be collected |
| Disposal |
Neutralise with NaOH, collect precipitate for hazardous waste |
| Sustainability rating |
★★☆☆☆ Concerning chemistry, but manageable with reuse |
Chromoskedasic Sabattier
| Aspect |
Brush Method |
Tray Method |
| Chemistry per session |
40–60ml dilute |
500ml–1L each |
| Waste generated |
Minimal (on prints) |
Significant sludge |
| Disposal complexity |
Low |
High |
| Sustainability rating |
★★★☆☆ |
★☆☆☆☆ |
Key intervention: Always use brush application, never tray immersion
Alternative Processes
| Process |
Silver? |
Toxic Chemistry |
Disposal |
Rating |
| Cyanotype |
No |
No (ferric compounds are benign) |
Drain-safe |
★★★★★ |
| Anthotype |
No |
No (plant pigments) |
Compostable |
★★★★★ |
| Van Dyke Brown |
Yes |
Moderate (silver nitrate handling) |
Silver recovery needed |
★★★☆☆ |
| Kallitype |
Yes |
Moderate |
Silver recovery needed |
★★★☆☆ |
| Platinum/Palladium |
No |
Low (noble metals are inert) |
Drain-safe after neutralisation |
★★★★☆ |
| Gum Bichromate |
No |
HIGH (dichromate is carcinogenic) |
Hazardous waste |
★☆☆☆☆ |
Decision Tree
Want to minimise environmental impact?
│
├─ Printing?
│ ├─ B&W preferred → Standard B&W with silver recovery
│ ├─ Need colour → Scan + commercial RA-4
│ └─ Most sustainable → Cyanotype
│
├─ Experimental work?
│ ├─ Lith → Good choice (lower chemistry than standard)
│ ├─ Mordançage → Acceptable with reuse practices
│ ├─ Chromo → Only with brush method
│ └─ Toning → Avoid selenium if possible; sulfide is fine
│
└─ Alternative processes?
├─ Cyanotype → Excellent
├─ Anthotype → Best possible (but impermanent)
├─ Pt/Pd → Good (if you can afford it)
└─ Gum bichromate → Avoid (dichromate is carcinogenic)
Summary: The Hierarchy of Impact
| Rank |
Factor |
Contribution to Impact |
| 1 |
Silver in fixer/blix |
~80% |
| 2 |
Water consumption |
~10% |
| 3 |
Specific hazardous chemistry |
~5% |
| 4 |
Developer choice |
~2% |
| 5 |
Packaging/consumables |
~2% |
| 6 |
Energy |
~1% |
Address #1 and #2 first. Everything else is refinement.
Sustainable Darkroom series