Development of a New Sequential Extraction Procedure of Nickel Species on Workplace Airborne Particulate Matter: Assessing the Occupational Exposure to Carcinogenic Metal Species

Table 1

Ni species, with chemical formulas, solubility characteristics, 8h-TWA occupational exposure limits proposed by international agencies, and hazard statements assigned by the EU CLP Regulation, ACGIH, SCOEL, and OSHA.

Nickel Species		Solubility in water; (g/100ml); [temperature]	CAS Number	ACGIH	SCOEL	OSHA	CLP
Nickel Sulfate	NiSO4	65.5 [0°C]	7786-81-4	A4; 0.1 mg/m^3 (Ni Sol)	0.01 mg/m^3 #	-	H351
Nickel subsulphide	Ni3S2	poorly soluble	12035-72-2	A1; 0.1 mg/m^3	0.005 mg/m^3 §; 0.01 mg/m^3 #	0.1 mg/m^3; (Ni insol)	H350i
Nickel monoxide	NiO	poorly soluble	1313-99-1	A1; 0.2 mg/m^3; (Ni insol)	0.005 mg/m^3 §; 0.01 mg/m^3 #	0.1 mg/m^3; (Ni insol)	H350i
Metallic nickel	Ni	poorly soluble	7440-02-0	A5; 1.5 mg/m^3	0.005 mg/m^3 §	0.5 mg/m^3	H351

#Inhalable fraction; §respirable fraction.