Table 1.

Putatively identified compounds (based on queries against NIST EI database) of GC-MS analyzed Milli-Q water (H₂O) conditioned or not with PDMS devices prepared from various pre-polymer:curing agent ratios (20:1, 15:1, and 10:1) fabricated from either 3D-printed (3D) or SU-8 (SU-8) molds with their retention time (RT) and similarity score (SI).

Mold	Sample	RT (min)	SI*	Compound	Origin	m/z spectra
3D	10:01	4.216	447	N-Benzenesulfonylazetidin-3-one	Polyethylene	Supp. Fig. 1
		4.332	458	(2,3-Diphenylcyclopropyl)methyl phenyl sulfoxide	Unknown	Supp. Fig. 2
		4.582	434	4-Phenylbutan-2-ol, tert-butyldimethylsilyl ether	Unknown**	Supp. Fig. 3
		5.997	715	Fumaronitrile	Plastic monomer	Supp. Fig. 4
		10.176	636	1,1,3,3,5,5,7,7,9,9,11,11-Dodecamethyl-hexasiloxane	PDMS oligomer	Supp. Fig. 5
	15:01	6.214; 11.908; 28.392	548; 640;635	1,1,3,3,5,5,7,7,9,9,11,11-Dodecamethyl-hexasiloxane	PDMS oligomer	Supp. Fig. 6
		6.597	826	Toluene	PDMS curing agent	Supp. Fig. 7
		5.947	459	2-Cyanosuccinonitrile	Unknown	Supp. Fig. 8
		4.299	504	4-(4-chlorobenzylideno)-3-methyl-1-phenyl-pyrazol-5(4 H)-one	Unknown	Supp. Fig. 9
		4.166	409	2,2,2-Trichloroethanol, methyl ether	Unknown	Supp. Fig. 10
	20:01	6.214	615	1,1,3,3,5,5,7,7,9,9,11,11-Dodecamethylhexasiloxane	PDMS oligomer	Supp. Fig. 11
		15.887; 24.446	702; 615	Dodecamethylcyclohexasiloxane	PDMS oligomer	Supp. Fig. 12
		11.192	800	Octamethyltetrasiloxane	PDMS oligomer	Supp. Fig. 13
		10.143	632	Methyl N-hydroxybenzenecarboximidoate	Fungicide**	Supp. Fig. 14
		7.179	933	Dimethylsilanediol	Degradation of silicones**	Supp. Fig. 15
SU-8	10:01	12.341	660	1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-Hexadecamethyl-octasiloxane	PDMS oligomer	Supp. Fig. 16
		5.731	529	4-Methyl-2-trimethylsilyloxy-trimethylsilyl ester benzoic acid	Unknown	Supp. Fig. 17
		4.332	419	(2-Benzyl-benzoimidazol-1-yl)-propane-1,2-diol	Unknown	Supp. Fig. 18
		4.099	410	Pyrazol-5(4 H)-one, 4-(4-chlorobenzylideno)-3-methyl-1-phenyl	Unknown	Supp. Fig. 19
	15:01	29.574	673	1,1,3,3,5,5,7,7,9,9,11,11-Dodecamethyl-hexasiloxane	PDMS oligomer	Supp. Fig. 20
		8.944	671	Octamethyl-cyclotetrasiloxane	PDMS oligomer	Supp. Fig. 21
		5.514	741	4-Methoxybenzyl alcohol	Catalyst	Supp. Fig. 22
		5.365	594	4,6-Heptadiyn-3-one	Unknown	Supp. Fig. 23
		4.416	510	2-(Chloroethenyl)-1,3-butadiene	Unknown	Supp. Fig. 24
		4.266	573	(Chloromethyl)dimethyl-phosphine oxide	Unknown	Supp. Fig. 25
		4.149	573	2-Chloro-ethanesulfonyl chloride	Epoxy resin component	Supp. Fig. 26
	20:01	13.457	676	1,1,3,3,5,5,7,7,9,9,11,11-Dodecamethyl-hexasiloxane	PDMS oligomer	Supp. Fig. 27
		6.014	690	1,1,3,3,5,5,7,7-Octamethyl-7-(2-methylpropoxy)tetrasiloxan-1-ol	PDMS oligomer	Supp. Fig. 28
		4.449	525	Chalcone	Epoxy resin component	Supp. Fig. 29
		4.366	454	4-(4-Chlorobenzylideno)-3-methyl-1-phenyl-pyrazol-5(4 H)-one	Unknown	Supp. Fig. 30

*SI was calculated based on EI peak matching of the experimental data against the NIST EI database.

**indicates compounds also detected in water (control samples).