Aldehydes others than formaldehyde: exposure patterns and their significance in a set of Italian indoor workplaces - 2011-2020

  • Roberto Calisti ASUR MARCHE – Area Vasta 3 – Unit SPreSALfor Occupational Safety and Health
  • Antonio Francesco Chiaverini ASUR MARCHE – Area Vasta 3 – Unit SPreSALfor Occupational Safety and Health
  • Rossano Mei ASUR MARCHE – Area Vasta 3 – Occupational Safety and Health
Keywords: formaldehyde; acetaldehyde; hexanal; occupational exposure; passive sampling; risk assessment; risk control; prevention


Aldehydes are fragrant compounds with widely diversified smells (ranging from very pleasant to very unpleasant), presenting a potential for local irritation of the mucous membranes and other adverse health effects.

Formaldehyde is the compound from this family receiving the largely prevalent attention in the fields of the industrial hygiene and of the occupational and environmental medicine; recognised as an irritating, allergenic and carcinogenic agent, it is ubiquitous, causing widespread exposures in both occupational and non- occupational scenarios, frequently rising up to relevant concentrations.

In the vast majority of the anthropized indoor environments, formaldehyde is the most abundant aldehyde too (referring both to spreading and concentration levels in air) but it is worth noting that it is virtually always accompanied by a various cortege of other aldehydes.

Some aldehydes, others than formaldehyde, can show a relevant presence in particular scenarios, notably acetaldehyde inside settings where flours are rising and being baked, acrylaldehyde (commonly known as acrolein) where cooking oils are heated overwhelming their smoke point, glutaraldehyde in healthcare contexts where the agent is used as a disinfectant, benzaldehyde and crotonaldehyde where these two chemicals are synthesized and used for industrial purposes.

 In a preventive perspective, these facts call for an attention towards the whole family of aliphatic aldehydes.

Different patterns of combined exposure to formaldehyde and other aldehydes in a set of Italian indoor workplaces are presented and discussed.

Over the 2011 – 2020 period, a sequence of passive diffusive samplings was performed, partly in workplaces previously known for having relevant sources of formaldehyde and / or other aldehydes, partly in workplaces without no previously known source of these chemicals. The set of the studied workplaces didn’t comprehend scenarios where cooking oils were heated, glutaraldehyde was used as a disinfectant, benzaldehyde or crotonaldehyde were synthesized or used for industrial purposes.

In several cases acetaldehyde showed significant concentrations in air, often presenting as the main companion of formaldehyde.

Acetaldehyde concentrations in air reached 568 μg m-3 in agriculture and zootechnics, 144.9 μg m-3 in the plastics moulding sector, and 48.4 μg m-3 in hairdressers’ and beauticians’ workshops.

In the bread and pastry baking sector, acetaldehyde concentrations in air resulted frequently relevant (up to 256.3 μg m-3), in the absence of a similar presence of formaldehyde (top level 29.2 μg m-3).

Unexpectedly, in some samples from the healthcare sector, acetaldehyde concentrations reached significant levels (up to 159.5 μg m-3 from personal 15’ samplings), close to the corresponding formaldehyde ones (up to 332.6 μg m-3 from personal 15’ samplings).


Hexanal emerged as a relevant compound (concentrations in air up to 174.1 μg m-3) in miscellaneous scenarios comprising healthcare, plastics moulding, wood, plywood and chipboard, paper and paperboard, bakeries and pastries.

Other aldehydes were detected in multiple situations, individually at levels never exceeding 10.0 μg m-3, but sometimes accounting for not fully negligible overall concentrations in air.   

These results suggest that, in a variety of indoor workplaces, a skilled preventive attention deserves to be addressed not only to formaldehyde, but to the whole body of the aldehydes, in front of a reasonable possibility of synergic actions.

Such an indication assumes a major relevance under the hypotheses that protracted oxidative stress and chronic inflammation are the driving modes of the formaldehyde’s carcinogenic effect, through the piling up of unrepaired damages to DNA.


Aprea, C., Bozzi, N., Nanni C., Cardelli, D., Pulcinelli, R., Sciarra, G., 2007. Formaldeide e acetaldeide nelle rivendite di mobili. Giornale degli Igienisti Industriali, 32 (2): 109-119.

Aprea, MC, Miligi L, 2019. Il rischio cancerogeno da formaldeide nelle evidenze epidemiologiche e nelle esperienze di igiene industriale: esiste un confine tra esposizioni in ambienti di vita e di lavoro ? in Atti del workshop “CANC TUM 2018”, Civitanova Marche, 28-30 giugno 2018, 311-338.

Calisti, R., Isolani, L., Mei, R., 2018. Formaldehyde exposure patterns in a set of Italian indoor workplaces with and without specific emission sources - 2011 – 2018. It. J. Occup. Environ. Hyg.; 9 (4): 165-175.

Cho Y, Song MK, Kim TS, Rye JC, 2018. DNA methylome analysis of saturated aliphatic aldehydes in pulmonary toxicity. Sci. Rep.; 8 (1): 10497.

Cocheo, V., Boaretto, C., Sacco, P., 1996. High uptake rate radial diffusive sampler suitable for both solvent and thermal desorption. Am. Ind. Hyg. Assoc. J., 57, 897-904.

EN 482, Workplace exposure - General requirements for the performance of procedures for the measurement of chemical agents, European Committee for Standardization, Bruxelles, 2015.

EN 689, Workplace atmospheres. Guidance for the assessment of exposure by inhalation to chemical agents for comparison with limit values and measurement strategy, European Committee for Standardization, Bruxelles, 2018.

EU (European Union), 2019. Directive (EU) 2019/983 of the European Parliament and of the Council 5 June 2019 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work. Official Journal of the European Union: L 164/23 – 164/29.

Ferdenzi P, Bedogni L, 2019. Monitoraggio delle esposizioni occupazionali a formaldeide nel comparto stampaggio materie plastiche: confronto tra i dati del sistema pubblico e quelli delle aziende. in Atti del workshop “CANC TUM 2018”, Civitanova Marche, 28-30 giugno 2018, 357-370.

González Jara MA, Mora Hidalgo A, Avalos Gulin JC, López Albiach M, Muñoz Ortiz L, Torán Monserrat P, Esteva Ollé X, 2013. Exposure of health workers in primary health care to glutaraldehyde. J Occup Med Toxicol; 81(1): 31.

Ho SS, Ip HS, Ho KF, Ng LP, Chan CS, Dai WT, Cao JJ, 2013. Hazardous airborne carbonyls emissions in industrial workplaces in China. J Air Waste Manag Assoc; 63(7): 864-77.

Hodgson AT, Beal D, McIlvaine JER, 2002. Sources of formaldehyde, other aldehydes and terpenes in a new manufactured house. Indoor Air; 12(4): 235-42.

Kromhout, H., 2016. Hygiene without numbers. Ann. Occup. Hyg., 60 (4): 403-4.

Lane RH, Smathers JL, 1991. Monitoring aldehydes production during frying by reversed-phase liquid chromatography. J Assoc Off Anal Chem; 74(6): 957-60.

Luecken D.J., Hutzell W.T., Strum M.L., Pouliot G.A., 2012. Regional sources of atmospheric formaldehyde and acetaldehyde, and implications for atmospheric modelling. Science Direct, 47: 477-490.

McGregor, D., Bolt, H., Cogliano, V., Richter-Reichelm, H.B., 2006. Formaldehyde and glutaraldehyde and nasal citotoxicity; case study within the context of the 2006 IPCS Human Framework for the Analysis of a cancer mode of action for humans. Crit. Rev. Toxicol., 36 (10): 821-35.

Smith DR, Wang RS, 2006. Glutaraldehyde exposure and its occupational impact in the health care environment. Environ Health Prev Med; 11(1): 3-10.

Suuronen K, Henriks-Eckerman ML, Riala R, Tuomi T, 2008. Respiratory exposure to components of water-miscible metalworking fluids. Ann Occup Hyg, 52(7): 607-14.

TOXNET, last access 2020 sep 16 (a). Benzaldehyde. National Library of Medicine HSDB Database.

TOXNET, last access 2020 sep 16 (b). Crotonaldehyde. National Library of Medicine HSDB Database.

Wang L, Csallany AS, Kerr BJ, Shurson GC, Chen C, 2016. Kinetics of forming aldehydes in frying oils and their distribution in French fries revealed by LC-MS-based chemometrics. J Agric Food Chem. 64(19): 3881-9.

Xie, M.Z., Shoulkamy, M.I., Salem, A.M., Oba, S., Goda, M., Nakano, T., Ide, H., 2016. Aldehydes with high and low toxicities inactivate cells by damaging distinct cellular targets. Mutat. Res.; 786: 41-51.

Zhang, S., Chen, H., Wang, A., Liu, Y., Hou, H., Hu, Q., 2017. Assessment of genotoxicity of four volatile pollutants from cigarette smoking based on the in vitro yH2AX assay using high content screening. Environ. Toxicol. Pharmacol.; 55: 30-36.

Zhang., S., Chen, H., Wang., A., Liu, Y., Hou, H., Hu, Q., 2018. Combined effect of co-exposure to formaldehyde and acrolein mixtures on cytotoxicity and genotoxicity in vitro. Environ. Sci. Pollut. Res. Int.; 25(25): 25306-25314.