Popping balloons can be more harmful than it seems

It is hoped that research carried out at London South Bank University on popping latex air-filled balloons for whatever purpose, will influence expert panels, professional bodies and safety regulators to incorporate the new knowledge in relevant future standards, codes of practice and safety advisory labelling.

By Dr Luis Gomez-Agustina of London South Bank University

Bursting latex balloons filled with air is a convenient method widely employed by acousticians and researchers to generate high intensity impulse sound signals in room acoustics investigations (Figure1).
This approach appears briefly in ISO 354:2003¹ as a potentially suitable impulse sound source for the determination of the room impulse response. The method is extensively employed in acoustic professional practice, education and acoustics research ² - ⁷ due to its portability, convenience, low cost and other practical merits⁸.

It is also a common activity performed at entertainment occasions and parties etc but owing to its harmless appearance, fun and leisure connotations, acoustic practitioners and lay users often inflate and burst air-filled party balloons unprotected and unsuspectingly, without being aware of the potential auditory risk that those bursts may have on their hearing health.

Above: Figure 1: An air-filled balloon being popped during an acoustic survey

Rationale, aim and significance of the study
In addition to the intentional puncturing and subsequent bursting, balloons often pop accidentally or unexpectedly. The apparent high loudness and close proximity to the exploding balloon, suggests a potential risk of noise induced hearing loss (NIHL) or hearing damage could occur to the persons inflating, handling or holding and puncturing the balloon, as well as to anyone else present in the room.

The total absence of noise exposure, auditory risk information and lack of safety guidance or standardisation in the execution of the balloon burst method in the literature motivated the investigation into the subject. The potential irreversible hearing damage risk and the large population that can be affected added further motivation and significance to the study.

The study aimed to provide for the first time a comprehensive investigation to determine and assess the noise exposure and the risk of hearing damage from bursting air-filled latex balloons as utilised in room acoustics surveys, education and leisure activities. Another aim was to raise awareness and educate acoustic practitioners, professional bodies, and lay users on the associated auditory risks. Derived from its findings, the study provides novel and detailed guidance on safe procedures to be adopted during acoustic measurements or other purposes such as leisure activities.

Above: Figure 2: Puncturing a large balloon at a distance during acoustic measurements in a lecture theatre

Method and materials
The experimental method consisted of taking peak sound pressure level measurements at several distances from the bursts of manually punctured balloons previously inflated with air to the same inflation level. Three suitable hand-held acoustics analysers performed the measurements simulating unprotected human receivers being exposed to the balloon burst impulse sound (figure 2).

The test procedure replicated typical test procedures and practices employed by professional practitioners in room acoustics surveys while satisfying the relevant European Directive 2003/10/EC⁹ and UK occupational Control of Noise Regulations 2005¹⁰ test requirements. To examine the effect of the balloon size, three common sizes of commercially available latex party balloons were used and named here in reference to their nominal inflated size measured at the equatorial line: small (23cm), large (38cm) and giant (91cm).

To evaluate the influence of the acoustic environment, three types of rooms of different dimensions, volume, shape, reverberation, absorption and diffusion properties were chosen (a home cinema, a hall of residence lounge and lecture theatre). The combination of the three variables (balloon types, exposure distances and rooms) generated 27 exposure scenarios. (In this article only results for the lecture theatre are shown.)

To investigate the effect of the distance between the burst and the receptor’s ear, three measurement distances were used to represent the exposure distances of the person holding and puncturing the balloon at 0.5 metres (reference exposure distance, see figure 1) and of people present in the same room positioned at three metres and six metres from the burst. Three microphones were positioned at the three exposure distances and were connected to calibrated acoustic analysers to measure simultaneously at the three distances levels of L Cpeak and L peak.

Measured values were assessed against the limits specified by relevant international occupational noise regulations ⁹ - ¹¹ , ¹² - ¹⁴ to determine the level of exposure and the risk of hearing damage. Based on the values measured and by means of calculation, other relevant information was obtained (presented elsewhere¹⁵) such as the unprotected critical distance, the predicted effect of hearing protection on exposure levels and of estimated exposure to multiple burst events. 

References
1. ISO 354:2003 Acoustics - Measurements of Sound absorption in a reverberation room.
2. Iannace, G. and Trematerra, A. (2014) The acoustics of the caves, Applied Acoustics, 86, pp. 42-46.
3. Fausti, P. and Farina, A. (2000) Acoustic measurements in opera houses: Comparison between different techniques and equipment, Journal of Sound and Vibration, 232 (1), pp. 213-229.
4. Abel, J.S., Bryan, N.J., Huang,P.P., Kolar,M., and Pentcheva,B.V. (2010) Estimating room impulse responses from recorded balloon pops, Audio Engineering Society Convention 129, Audio Engineering Society.
5. Iannace, G., Trematerra, A. and Masullo, M. (2013) The large theatre of Pompeii: Acoustic evolution, Building Acoustics, 20 (3), pp. 215-227.
6. Sukaj, S., Bevilacqua, A., Iannace, G., Lombardi, I., Parente, R. and Trematerra, A. (2022) Byzantine churches in Albania: How geometry and architectural composition influence the acoustics, Buildings, 12 (3), pp. 280.
7. Horvat, M., Jambrosic, K., and Domitrovic, H. (2008). A comparison of impulse-like sources to be used in reverberation time measurements, Proceedings of Acoustics2008, Paris, France.
8. Gomez-Agustina, L. and Barnard, J. (2019) Practical and technical suitability perceptions of sound sources and test signals used in room acoustic testing. In INTER-NOISE and NOISE-CON Congress and Conference Proceedings (Vol. 259, No. 2, pp. 7076-7087). Institute of Noise Control Engineering.
9. European Directive 2003/10/EC (noise). European Parliament and Council 6 February 2003, Minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents.
10. The Control of Noise at Work Regulations (2005), London: HMSO. SI 2005/1643.
11. National Institute for Occupational Safety and Health. (1998) Occupational Noise Exposure, Revised Criteria 1998. DHHS, Cincinnati, OH, pp. 1e105.
12. OSHA (2008) Occupational Safety and Health Standards -1910 Subpart G. Occupational Noise exposure, 29 CFR 1910.95(b)
13. Canadian Centre for Occupational Health and Safety (2015), Noise-Occupational Exposure Limits in Canada. [online]. [Accessed 17 December 2024]. Available from https://www.ccohs.ca/oshanswers/phys_agents/noise/exposure_can.html
14. Berglund, B., Lindvall, T., Schwela, D. H. (1999) Guidelines for community noise World Health Organization.
15. Gomez-Agustina, L., Bevilacqua, A. and Vazquez-Barrera, P., 2025. Noise exposure and auditory risk from air-filled balloon bursts. Applied Acoustics, 232, p.110568. https://doi.org/10.1016/j.apacoust.2025.110568

Above graphs: Figure 3: Unprotected exposure levels measured in the lecture room at three exposure distances for three different balloon size types. a) shows values of L Cpeak and b) shows values of L peak

Results and analysis
Figure 3 presents balloon burst unprotected noise exposure levels measured in the lecture theatre at three exposure distances. Values shown are the average of 15 bursts of the same balloon size type and error bars denote the corresponding standard deviation (std). Horizontal purple and green dotted arrows in figure 3a indicate the upper and lower L Cpeak action levels respectively (L Cpeak = 137 dB and L Cpeak = 135 dB) for impulsive sound for the unprotected ear of the European Directive 2003/10/ EC (noise)⁹ and the UK Control of Noise at Work Regulations 2005 (Noise Regulations)¹⁰ .

Horizontal red dotted arrows in figure 3b indicate the USA and Canadian occupational health and safety agencies’ maximum permissible limit (L peak = 140 dB) for impulsive sound for the unprotected ear 11-13 . Black dotted arrows in figure 3b denotes the World Health Organization (WHO) 14 maximum permissible unprotected impulse noise exposure level for children (L peak = 120 dB). In figure 3a it can be seen that the large balloon and the giant balloons in the lecture theatre exceeded the Noise Regulations¹⁰ upper action level at the reference exposure distance (0.5m) by 4.8 dB and 0.1 dB respectively. Reaching or surpassing any of the two action levels implies that a risk of hearing damage increases considerably¹⁰.

Figure 3b shows that the large balloon in the lecture theatre surpassed at the reference exposure distance the maximum permissible impulse noise exposure level of the USA and Canadian occupational regulations ¹¹ - ¹³ by 3 dB. Considering the maximum permissible unprotected impulse noise exposure level for children, in figure 3b it shows that level was exceeded at the reference distance by the three balloon sizes between 13 dB and 23dB.

Conclusions
Latex party balloons filled with air are widely used in a variety of activities. In acoustic research and professional practice, the burst of the balloon is employed as an impulse sound source to obtain room acoustic parameters. Due to its presumed harmless appearance and leisure connotations, acoustic practitioners and lay users often inflate and pop balloons unprotected and unsuspectingly without being aware of the serious auditory risk that those bursts may entail to their hearing health.

This research investigates for the first time the noise exposure from popping air-filled latex balloons for a range of likely settings and assesses the risks of hearing damage against a range of relevant international occupational health regulations. The bursts from two commonly used balloon sizes (large and giant) produced peak sound pressure levels at the ear of an unprotected person holding and puncturing the balloon that exceeded various international occupational health regulatory exposure limits. According to various international occupational health and safety regulations that exceeded exposure from a single ballon burst found in this study constitutes a risk of permanent hearing damage.

Children’s maximum unprotected permissible exposure limit was virtually exceeded by the large and giant balloon sizes at all exposure distances in all rooms. Motivated from the concerning findings presented in this study, the authors propose the creation of an international normative to require a prominent safety warning label and/or basic safety instructions to accompany every balloon package as an effective and inexpensive measure to minimise risk of hearing damage from balloon bursts. It is expected that the findings, insights and safety guidance generated in this study will raise awareness, change attitudes and practices of acoustic practitioners and general lay users. This consequently will reduce the risk of hearing damage and aid professionals to comply with applicable occupational health and safety regulations.

This article summarises research undertaken at London South Bank University and is based on a journal article published in Applied Acoustics entitled Noise exposure and auditory risk from air-f i lled balloon bursts authored by Dr Luis Gomez-Agustina, Antonella Bevilacqua and Pedro Vazquez-Barrera. The journal article is freely available here https://doi.org/10.1016/j.apacoust.2025.110568

References
9. European Directive 2003/10/EC (noise). European Parliament and Council 6 February 2003, Minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents.
10. The Control of Noise at Work Regulations (2005), London: HMSO. SI 2005/1643.
11. National Institute for Occupational Safety and Health. (1998) Occupational Noise Exposure, Revised Criteria 1998. DHHS, Cincinnati, OH, pp. 1e105
12. OSHA (2008) Occupational Safety and Health Standards -1910 Subpart G. Occupational Noise exposure, 29 CFR 1910.95(b).
13. Canadian Centre for Occupational Health and Safety (2015), Noise-Occupational Exposure Limits in Canada. [online].[Accessed 17 December 2024]. Available from https://www.ccohs.ca/oshanswers/phys_agents/noise/exposure_can.html