Table 2.
Recommended guidelines for formaldehyde and acetaldehyde concentrations in indoor and outdoor air.
| Formaldehyde | |||||
| Country | Guideline values (μg m−3) | Exposure time | Outdoor or indoor | Additional information | Reference |
| Japan | 10 | – | Outdoor | Histopathological changes | (Naya and Nakanishi, 2005) |
| China | 30 | 8-h | Indoor | – | (Salthammer et al., 2010) |
| Finland | 30 | – | Indoor | Individual indoor climate | (Säteri, 2002) |
| 50 | – | Indoor | Good indoor climate | (Säteri, 2002) | |
| 100 | – | Indoor | Satisfactory indoor climate | (Säteri, 2002) | |
| France | 50 | 2 h | Indoor | – | (Salthammer et al., 2010) |
| France | 10 | LTEL | Indoor | – | (Salthammer et al., 2010) |
| Iran-OEL | 370 “C” | – | Indoor | URT; eye irritation; suspected human carcinogen | (ITCOH, 2012) |
| U.S-ATSDR | 49 | – | Indoor | Acute minimal risk revel and changes in human nasal lavage fuid | (Pazdrak et al., 1993) |
| 37 | – | Indoor | Intermediate minimal risk revel and chronic inhalation toxicity in animals | (Rusch et al., 1983) | |
| 10 | – | Indoor | Chronic minimal risk revel and Histological changes in human nasal mucosa | (Holmström et al., 1989) | |
| Canada | 123 | 1 h | Indoor | Eye irritation; Residential indoor air | (Canada, 2005) |
| 50 | 8-h | Indoor | Respiratory symptoms in children. Residential indoor air | (Canada, 2005) | |
| USA | 923 | 8-h | Indoor | Permissible exposure limits;Occupational standards | (OSHA, 2011) |
| 2460 | 15 min | Indoor | Permissible exposure limits;Occupational standards | (OSHA, 2011) | |
| Singapore | 100 | 8-h | Indoor | – | (Salthammer et al., 2010) |
| USA | 33 | 8-h | Indoor | Iinterim REL | (Guideline, 1991) |
| 3 | Annual average | Indoor | Chronic REL | (OEHHA, 2005) | |
| 20 | 8-h | Indoor | Recommendable exposure limit | (NIOSH, 2004) | |
| 150 | 15 min | Indoor | Recommendable exposure limit | (NIOSH, 2004) | |
| Europe | 100 | 30 min | Indoor | Air Quality Guidelines; Sensoryirritation | (RAIS, 2014) |
| Spain | 370 | STEL | Indoor | Occupational exposure | (Campo Ojeda, 2003) |
| OSHA | 923 | – | Indoor | – | (Eller and Cassinelli, 2003) |
| 2460 | STEL | Indoor | – | (Eller and Cassinelli, 2003) | |
| NIOSH | 20 | – | Indoor | – | (NIOSH, 2003) |
| 123 “C” | – | Indoor | – | (NIOSH, 2003) | |
| ACGIH | 370 “C” | – | Indoor | URT; eye irritation; suspected human carcinogen | (ACGIH, 2014) |
| WHO-ROE | 100 | 30 min | Indoor | Nose and throat irritation in humans after short-term exposure | (WHO, 2000) |
| WHO | 100 | 30 min | Indoor | – | (WHO, 1987) |
| Acetaldehyde | |||||
| HSE | 66637 | 8-h | Indoor | – | (HSE, 2011) |
| 92000 | 15 min (STEL) | Indoor | – | (HSE, 2011) | |
| ACGIH | 45025 “C” | 15 min (STEL) | Indoor | URT; eye irritation | (ACGIH, 2014) |
| Iran-OEL | 45025 “C” | – | Indoor | URT; eye irritation | (ITCOH, 2012) |
| OSHA | 360200 | – | Indoor | – | (NIOSH, 1993) |
| ACGIH | 18010 | STEL | Indoor | – | (NIOSH, 1993) |
| 27015 | – | Indoor | Suspect carcinogen | (NIOSH, 1993) | |
“C” = Ceiling limit; URT = Upper respiratory tract; STEL= Short-term exposure limit; REL = Reference exposure limit; U.S-ATSDR= U.S- Agency for Toxic Substances and Disease Registry; Iran-OEL= Iranian occupational exposure limit; HSE=Health and Safety Executive; WHO-ROE = World Health Organization, Regional Office for Europe; LTE = Long-term exposure Limit.