Table 2.

Overview of animal experiments

Investigation number	Particles	Animal species and number (N) of animals	Dispersion media tested	Exposure period and end points (comet assay system)
1	162 µg/mouse (8 mg/kg bw) CB or 54 µg/mouse (2.7 mg/kg bw) CNT	Mouse	Nanopure water (CB)	24 h:
		n = 6 per group (in total n = 72)	2% serum in Nanopure water (CB, CNT)	BAL neutrophils, Saa3 and Mcp-1 mRNA
			0.05% serum albumin in Nanopure water and powder pre-wetting with 0.5% (v/v) ethanol (CB, CNT)	DNA strand breaks (Andor Komet 6)
			10% BAL fluid in 0.9% NaCl (CB)
			10% BAL fluid in Nanopure water (CB)
2	162 µg/mouse (8 mg/kg bw) CB	Mouse	0.1% Tween-80 in Nanopure water	24 h:
		n = 7 per group (in total n = 14)		BAL neutrophilsDNA strand breaks (IMSTAR)
3	162 µg/mouse (8 mg/kg bw) CB	Mouse	Nanopure water	3, 5 and 28 days:
		n = 8 per group (in total n = 144)	2% serum in Nanopure water	BAL neutrophils
			0.05% serum albumin in Nanopure water and powder pre-wetting with 0.5% (v/v) ethanol	DNA strand breaks (IMSTAR)
4	67 µg/mouse (3.3 mg/kg bw) TiO2 NRCWE-001, NRCWE-002 or NRCWE-025	Mouse	For TiO2 particles: Nanopure water 2% serum in Nanopure water 0.05% serum albumin in Nanopure water and powder pre-wetting with 0.5% (v/v) ethanol	24 h:BAL neutrophilsDNA strand breaks (IMSTAR)
	162 µg/mouse (8 mg/kg bw) CB	n = 8 per group (except NRCWE-001 in 2% serum n = 7) (in total n = 103)
			For CB: 2% serum in Nanopure water
5	1620 µg/rat (5.4 mg/kg bw) CB	Rat	Nanopure water	24 h:
		n = 6 per group (in total n = 24)	0.05% serum albumin in Nanopure water and powder pre-wetting with 0.5% (v/v) ethanol	BAL neutrophilsDNA strand breaks (Andor Komet 6)