. Author manuscript; available in PMC: 2022 Dec 17.

Published in final edited form as: J Toxicol Environ Health B Crit Rev. 2021 Jun 17;24(5):173–222. doi: 10.1080/10937404.2021.1936319

Table 3.

Summary of particle-phase personal breathing zone exposures among additive manufacturing workers.

Room (m³)	ACH (h⁻¹)	Feedstock^a	Scenario^b	Sampler^c	Specifics	Analysis^d	Analyte^e	C (μg/m³)	Cit.^f
Directed energy deposition AM process category
NR	NR	316 L SS	End of build	miniDiSC	Real-time	n/a	Particles	5.0 × 10⁶ ^#	A
Material extrusion AM process category
66	NR	ABS, PLA Employee 1	3-DP	NRD	10 to 300 nm	ICP-MS	Al	10	B
40	NR	ABS, PLA Employee 1	3-DP/AVP	NRD	10 to 300 nm	ICP-MS	Al	20
40	NR	ABS, PLA Employee 2	3-DP/AVP	NRD	10 to 300 nm	ICP-MS	Fe	10
66	NR	ABS, PC	FDM^™	NRD	10 to 300 nm	ICP-MS	Al	Up to 10	C
				NRD	10 to 300 nm	ICP-MS	Fe	Up to 10
40	NR	ABS, PLA	3-DP	NRD	10 to 300 nm	ICP-MS	Al	10–20	D
76	NR	ABS	3-DP	NRD	10 to 300 nm	ICP-MS	Al	10–20
303	29	PEEK CNF/CNT	3-DP	OFC (MCE)	Total	TEM	CNF/CNT	Present^*	E
Material jetting AM process category
90	0.22 estimated	TangoBlack+, VeroClear	Printing	NRD	10 to 300 nm	ICP-MS	Al	Up to 10	C
		TangoBlack+, VeroClear		NRD	10 to 300 nm	ICP-MS	Fe	Up to 10
Powder bed fusion AM process category
NR	NR	Inconel 939	Pre-/printing tasks	CFC (MCE)	Total	ICP-MS	Cr	44	F
				CFC (MCE)	Total	ICP-MS	Co	38
				CFC (MCE)	Total	ICP-MS	Ni	99
				CFC (MCE)	Total	ICP-MS	Mn	0.17
NR	NR	Inconel 718, Ti64	Pre-/post-printing tasks	Cyclone (CN)	Inhalable	GF-AAS	Ni	12.5	G
				Cyclone (CN)	Inhalable	GF-AAS	Cr	3.5
				Cyclone (CN)	Inhalable	ICP-MS	Fe	10
				Cyclone (CN)	Inhalable	GF-AAS	Ti	11.5
				Cyclone (CN)	Inhalable	FAAS	Al	104
				Cyclone (CN)	Respirable	GF-AAS	Ni	0.6
				Cyclone (CN)	Respirable	GF-AAS	Ti	1.6
NR	NR	304 L SS	Printing – Year 1	IOM (MCE)	Inhalable	ICP-MS	Cr	6.8–86.8	H
				IOM (MCE)	Inhalable	ICP-MS	Fe	114.7–253.8
				IOM (MCE)	Inhalable	ICP-MS	Ni	6.6–268.9
			Printing – Year 2	IOM (MCE)	Inhalable	ICP-MS	Cr	3.0–331.0
				IOM (MCE)	Inhalable	ICP-MS	Fe	23.9–283.3
				IOM (MCE)	Inhalable	ICP-MS	Ni	5.1–715.7
			Printing – Year 1	OFC (MCE)	Total dust	ICP-MS	Cr	2.0–59.4
				OFC (MCE)	Total dust	ICP-MS	Fe	100.8–253.8
				OFC (MCE)	Total dust	ICP-MS	Ni	2.0–256.1
NR	NR	Ti6Al4V	Emptying print chamber	miniDiSC	Real-time	n/a	Particles	4.2 × 10³	I
			PRS closed	miniDiSC	Real-time	n/a	Particles	0.6 × 10³
			PRS open	miniDiSC	Real-time	n/a	Particles	1.5 × 10³
			Baking	miniDiSC	Real-time	n/a	Particles	1.0 × 10³
			Grinding	miniDiSC	Real-time	n/a	Particles	3.6 × 10⁴

ABS = acrylonitrile butadiene styrene, CNF = carbon nanofiber, CNT = carbon nanotube, PC = polycarbonate, PEEK = poly ether ether ketone, PLA = polylactic acid, SS = stainless steel

3-DP = desktop-scale fused filament fabrication 3-D printer, AVP = acetone vapor polishing post-processing task, FDM^™ = industrial-scale fused deposition modeling machine, PRS = powder removal system

CFC = close-faced cassette, CN = cellulose nitrate filter, MCE = mixed cellulose ester filter, OFC = open-faced cassette, NRD = nanoparticle respiratory deposition sampler

FAAS = flame atomic absorption spectrometry, GF-AAS = graphite furnace-atomic absorption spectrometry, ICP-MS = inductively coupled plasma-mass spectrometry, TEM = transmission electron microscopy

Al = aluminum, CNF = carbon nanofiber, CNT = carbon nanotube, Co = cobalt, Cr = chromium, Fe = iron, Mn = manganese, Ni = nickel, Ti = titanium

A = Bau et al. (2020), B = Du Preez et al. (2018b), C = Stefaniak, Johnson, du Preez, Hammond, Wells, Ham, LeBouf, Martin, et al. (2019b), D = Stefaniak, Johnson, du Preez, Hammond, Wells, Ham, LeBouf, Menchaca, et al. (2019c), E = Dunn, Dunn, et al. (2020), F = Graff et al. (2017), G = Walter et al. (2018), H = Ljunggren et al. (2019), I = Jensen et al. (2020)

^{# =}

number concentration (#/cm³)

Free CNT and polymer particles that contained CNF/CNT

NR = not reported