Table 2. Hazards and ecotoxicology of nitrification and urease inhibitors

Type of inhibitor		Hazard risk	Ecotoxicology	Residues in animal products
Urease inhibitor	NBPT	Causes serious eye damage [97]	Low acute in aquatic and terrestrial [97]	No residues were found on milk and bovine tissue from dairy cow [67]
		Suspected of damaging fertility or the unborn child [97]
Nitrification inhibitor	DCD	Low hazard potential [69]	Low toxicity [69]	Minute residues in milk was found in 2013 in New Zealand [64]
				Administration of DCD to dairy cow at 3 or 30 g/cow/day was 1.2% recovered in milk [65]
	DMPP	Harmful if swallowed [96]	No hazards identified for air [96]No potential for bioaccumulation for predators [96]	Not available
		Causes serious eye irritation [96]
		Suspected of damaging fertility or the unborn child [96]
		May cause damage to organs through prolonged or repeated exposure [96]

NBPT, N-(n-butyl) thiophosphoric triamide; DCD, dicyandiamide; DMPP, 3-4 dimethylpyrazole phosphate.