Registration Dossier

Administrative data

Description of key information

Eye irritation

Skin irritation

Respiratory irritation

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Additional information

Carbon monoxide (CO) is not an irritant gas.

The wealth of data in the public domain (EPA, 2010; EHC, 1999) have reported no significant signs of irritation to the skin or eye. In addition, regarding respiratory irritation, EHC concluded that it is unlikely that CO has any direct effects on lung tissue (except for extremely high concentrations associated with CO poisoning). Human studies on the effects of CO on pulmonary function are complicated by the lack of adequate exposure information, the small number of subjects studied and the short exposures explored. Occupational or accidental exposure to the products of combustion and pyrolysis, particularly indoors, may lead to acute decrements in lung function if the carboxyhaemoglobin levels are high. It is difficult, however, to separate the potential effects of CO from those due to respiratory irritants in the smoke and exhaust. Community population studies on CO in ambient air have not found any significant relationship with pulmonary function, symptomatology and disease (endpoints which would be affected by irritants of the respiratory system). Therefore, no specific testing for respiratory irritation is considered necessary.

References:

EHC, 1999. Environmental Health Criteria, 213, International Programme for Chemical Safety, WHO.

EPA, 2010. Integrated Science Assessment for Carbon Monoxide. EPA/600/R-09/019F. January 2010.

Justification for classification or non-classification

As carbon monoxide is a gas, skin and eye irritation is unlikely to be a relevant endpoint. No respiratory irritation effects were observed during the acute inhalation tests. Therefore carbon monoxide has not be classified as a skin, eye or respiratory irritant.