Non-methane volatile organic compound emissions from malt whisky maturation: final report

7 Conclusions and recommendations

This report has demonstrated that based on the available evidence the health and environmental impacts of NMVOC emissions from Scotch whisky maturation are likely to be minor. However, further investigation and research is necessary to fully understand, assess and mitigate against those impacts.

As part of this assessment, the spatial distribution of NMVOC emissions was determined. Our analysis has found that the geographical spread of NMVOC emissions from the Scotch whisky industry is uncertain, due to the data informing the spatial distribution of emissions in the National Atmospheric Emissions Inventory (NAEI) stemming from surveys conducted in the 1990s. New bonded warehouses in particular have not been reported to the NAEI compilers. It is therefore recommended that updated information on the geographical distribution of Scotch whisky activity is provided to the NAEI compilers to enable an accurate picture of the distribution of NMVOC emissions from the sector to be established.

Existing regulatory emission databases were also considered to determine the spatial distribution of Scotch whisky NMVOC emissions. Scotch whisky facilities are not normally reported to regulatory databases such as the UK-PRTR or SPRI as maturation is not an activity covered by these reporting streams. Additionally, Scotch whisky facilities rarely meet reporting thresholds for industrial reporting streams, such as the activity threshold for daily production of spirits. Emissions from these facilities are therefore not included in such industrial emissions databases and were therefore not available to review for this project.

In addition to the spatial and monitoring limitations identified as part of this review, determining the likely human health and environmental impacts of emissions from Scotch whisky production has proven challenging due to a lack of high-quality data and a lack of prior research. There is limited published evidence on the health and environmental impacts of whisky maturation including little data on the impact of NMVOC emissions on ozone formation or their impact on climate. Although the human health impact of ozone production from Scotch whisky NMVOC emissions is likely to be minor based upon the currently available evidence, it is recommended that increased monitoring of ozone is performed, particularly in rural locations where ozone concentrations are typically elevated. Increased monitoring could then feed into ozone modelling and source apportionment to develop a greater understanding of the contribution of the Scotch whisky industry to elevated ozone concentrations in Scotland.

On a review of available research it is clear that further investigation into the magnitude of long-term exposure to NMVOC emissions from whisky maturation via inhalation is necessary to fully determine the significance of their impact on human health. Based on the currently available evidence the health risks from inhalation (compared to ingestion) of ethanol are limited. Monitoring of ethanol concentrations at the fence-line of facilities would be useful to gauge a likely upper bound on the ethanol concentrations experienced at nearby sensitive receptors.

In order for the Scottish Government to fully determine the geographical, environmental and health impacts of NMVOC emissions from whisky maturation, the following recommendations and next steps have been identified:

1. Cross check all whisky production, maturation and storage facilities in the NAEI, COMAH and other applicable datasets;

2. Investigate introducing monitoring of ethanol concentrations at the fence-line of the largest whisky production, maturation and storage facilities, which could be on a voluntary basis by operators or as a research exercise by SEPA;

3. Conduct further investigation into determining the ethanol concentrations which can support the growth of Baudoinia compniacensis and review any future research on whether there are any human health impacts of Baudoinia compniacensis;

4. Further research the impact of ozone formation on human health and the contribution from whisky maturation through increased monitoring of ozone concentrations (particularly in rural areas) and source apportionment studies;

5. Research the potential human health and environmental impacts from secondary aerosol formation resulting from ethanol emitted into the atmosphere from Scotch whisky facilities;

6. Review any future research on the relative GWP of ethanol in comparison to CO₂ to evaluate the potential climate impacts of NMVOC emissions from whisky maturation;

7. Increase monitoring of conditions within Scotch whisky production, maturation and storage facilities to better understand the parameters that impact the rate of ethanol evaporation during maturation; and

8. Before any potential mitigation measures are introduced, conduct large-scale and long-term trialling and testing to ensure product quality is not affected.

Consideration of the above recommendations will provide the Scottish Government with further understanding of the possible environmental and health impacts of NMVOC emissions from whisky maturation. It will also facilitate consideration of whether any mitigation measures are required and, if so, what would be a proportionate and effective level of implementation.