Table 2 Summary of toxicological endpoints for isocyanates. The endpoints include carcinogenicity, genotoxicity, effects on reproductive systems and teratogenic properties for the most commercially important isocyanates. Target organs for short term and long term exposure as well as sensitization are also summarised

Isocyanic acid (ICA)

No

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

Severe (rabbit)

Severe (rabbit)

Methyl isocyanate (MIC)

Possible

Yes (Goswami et al. 1990)

Yes

Yes

Yes (Gupta & Prabha 1996)

Liver

Chronic obstructive lung disease

Yes (ACIGH 1986)

Yes (human)

Severe (human)

Severe (human)

Ethyl isocyanate (EIC)

N/A

Yes^a

Yes^a

Yes^a

Cholinesterase Inhibitor

Liver^a

Chronic obstructive lung disease ^e

Yes^a

Yes^a

Severe^a

Severe^a

Phenyl isocyanate (PHI)

Possible IARC rating: 2B^b

Yes (Bureau 2000)

No (Nehez et al. 1989)

No (Nehez et al. 1989)

N/A

N/A

Irreversible decline in pulmonary function (NIOSH 2004)

Yes (Karol & Kramarik 1996)

Yes (Pauluhn et al. 1995)

Severe (O’Neil 2006; Berufsgenossenschaft der chemischen Industrie 1997)

Yes (Berufsgenossenschaft der chemischen Industrie 1997)

Hexamethylene di-isocyanate (HDI)

Possible IARC rating: 2B^b

Yes^b (Marczynski et al. 2005; Bilban 2004; Bolognesi et al. 2001)

No (Sids OECD 2001)

N/A

Cholinesterase Inhibitor

Lungs (Montelius & Sant 2009)

Lesions in the nasal cavity (Sids OECD 2001)

Yes (Centers for Disease Cotrol and Prevention 2015b)

Yes (Centers for Disease Cotrol and Prevention 2015b)

Severe (Vernot et al. 1977)

Severe (Vernot et al. 1977)

Toluene-2,4-di-isocyanate (2,4-TDI)

Possible IARC rating: 2B

Contradictory (Mäki-Paakkanen & Norppa 1987; Lindberg et al. 2011)

N/A

N/A

Cholinesterase Inhibitor

Lungs (Lindberg et al. 2011)

Irreversible decline in pulmonary function (The National Institute for Occupational Safety and Health (NIOSH) 2004)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Toluene-2,6-di-isocyanate (2,6-TDI)

Possible IARC rating: 2B

Yes (Mäki-Paakkanen & Norppa 1987)

No^c, (Le Quesne et al. 1976)

N/A

Yes

Lungs (Fabbri et al. 1987)

Irreversible decline in pulmonary function (NIOSH 2004)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Yes (Centers for Disease Cotrol and Prevention 2015c)

Methylenebis (phenylisocyanate) (MDI)

Possible IARC rating: 2B^b

Contradictory (Bolognesi et al. 2001)

No (Zocca et al. 1990)

Yes (Buschmann 1990)

Insufficient evidence (Hughes et al. 2014)

Lungs (Hughes et al. 2014)

Irreversible decline in pulmonary function (Centers for Disease Cotrol and Prevention 2015e)

Yes (Zocca et al. 1990)

Yes (Zocca et al. 1990)

Yes (Zocca et al. 1990)

Yes (Zocca et al. 1990)

Isophorone di-isocyanate (IPDI)

N/A

No (European Aliphatic Isocyanate Producer Association 2013)

N/A

N/A

N/A

Lungs (NIOSH 2004)

Irreversible decline in pulmonary function (Centers for Disease Cotrol and Prevention 2015d)

Yes (Centers for Disease Cotrol and Prevention 2015d)

Yes (Centers for Disease Cotrol and Prevention 2015d)

Yes (Centers for Disease Cotrol and Prevention 2015d)

Yes (Centers for Disease Cotrol and Prevention 2015d)