Table 4.
Background-corrected airborne concentrations of organic gases for resin-associated tasks. Values are geometric mean and (geometric standard deviation) unless noted otherwise (n = 5 replicates)1.
| Task | Process 2 | 2-Hydroxypropyl Methacrylate * (μg/m3) | Acetaldehyde (μg/m3) | Acetone (μg/m3) | Ethanol‡ (μg/m3) | Methylene Chloride (μg/m3) | Styrene (μg/m3) |
|---|---|---|---|---|---|---|---|
| Pouring (resin) | SLA | 50.7 | 14.4–18.2† | 2.1–26.0 
|
3.6–14.0 
|
23.5–76.0 
|
<1.52 |
| DLP | <43.4 | 18.6–20.6 | 21.1 (1.4) | 6.7–26.2 
|
6.2 (2.5) | 4.1–8.9 | |
| Printing (resin) | SLA | 18.1–21.9 | 10.0–16.3 | 2.7–10.1† | 0.02–4.5† | 0.03–16.0 
|
<1.52 |
| DLP | 31.2 (1.5) A,B | 8.3 (1.4) | 13.6 (1.5) | 7.4 (3.2) | 3.4 (5.4) | 4.5 | |
| Recovery (resin) | SLA | 43.8 (1.2) A,† | 19.7–35.4 | 22.8 (1.9) | 14.2 (3.8) 
|
0.69–38.6 
|
<1.52 |
| DLP | 58.5 (2.8) A,† | 10.9 | 17.5 (1.5) | 9.7 (2.3) | 5.8 (1.9) | 17.6 | |
| Curing | SLA | 11.3 | 0.3–15.7 
|
15.9–23.6 | 4.6 (2.0) 
|
3.9 | <1.52 |
| DLP | 25.9 (1.8) B | 4.5–9.0 | 2.8–11.1† | 0.6 (9.4)† | <0.204 | 2.0–4.5 |
< = all samples below limit of detection, single value = one sample result above background, range = two or three sample results above background.
SLA = stereolithography, DLP = digital light processing.
Adjusted regression models (differences among tasks are the same for both printers and there is no difference between printers for each task). Within each column, capital letters for GM values that are not connected by the same letter are significantly different (p < 0.05). For example, using 2-Hydroxypropyl methacrylate data, the “Recovery A” task is significantly different than the “Curing B” task.
Mixed regression models (significant interaction between printer and task). SLA process—recovery > printing (p < 0.05); DLP process—recovery > curing (p < 0.05).
One of five replicate values imputed using β-substitution method (see Method section).
Two of five replicate values imputed using β-substitution method (see Method section).