Open Access Open Badges Research article

Using 'may contain' labelling to inform food choice: a qualitative study of nut allergic consumers

Julie Barnett1*, Kate Muncer2, Jo Leftwich2, Richard Shepherd2, Monique M Raats2, M Hazel Gowland3, Kate Grimshaw4 and Jane S Lucas4

Author Affiliations

1 Department of Information Systems and Computing, Brunel University, Uxbridge, Middlesex, UB8 3PH, UK

2 Department of Psychology, University of Surrey, Guildford, Surrey, GU2 7XH, UK

3 Allergy Action/Anaphylaxis Campaign, Farnborough, GU14 6SX, UK

4 School of Medicine, Division of Infection, Inflammation and Immunity, University of Southampton, Tremora Road, Southampton, S016 6YD, UK

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BMC Public Health 2011, 11:734  doi:10.1186/1471-2458-11-734

Published: 26 September 2011



Precautionary 'may contain' warnings are used to indicate possible allergen contamination. Neither food safety nor foods labelling legislation address this issue. The aim of this study is to understand how peanut and nut allergic adults interpret 'may contain' labelling and how they use this information when purchasing food.


Qualitative methods were used to explore both behaviour and attitudes. The behaviour and 'thinking aloud' of 32 participants were recorded during their normal food shop. A semi-structured interview also explored participants' views about 13 potentially problematic packaged foods. Transcribed data from these tasks were analysed to explore the interpretation of 'may contain' labelling and how this influenced food choice decisions.


Peanut and nut allergic individuals adopt a complex range of responses and strategies to interpret 'may contain' labelling. Many claimed such labelling was not credible or desirable; many ignored it whilst some found it helpful and avoided products with all such labelling. Interpretation and consequent decisions were not only based on the detail of the labelling but also on external factors such as the nature of the product, the perceived trustworthiness of the producer and on the previous experience of the nut allergic individual.


'May contain' labelling was interpreted in the light of judgements about the product, producer and previous personal experience. It is vital that these interpretation strategies are taken into account by those responsible for labelling itself and for the provision of advice to nut allergic individuals. Suggestions to improve labelling and advice to the allergic individual are considered.