Introduction to SEPA’s Odour guidance 

Following a public consultation we have published guidance on dealing with activities that could cause offensive odour. The guidance is aimed at SEPA officers involved in the regulation of activities that could give rise to offensive odours, but it can be referred to by others such as members of the public and industrial operators.

The guidance brings together guidance and practices used previously but which were documented in different places. It explains and considers international guidance on dealing with offensive odour, and is provided for all legislative areas we administer, such as the pollution prevention and control and waste management licensing regimes.

The guidance provides information on 5 main areas:

  • what is odour;
  • dealing with new or changed facilities;
  • regulating operational facilities; 
  • incident and complaint response; 
  • working with communities.

The guidance also includes comprehensive appendices on odour thresholds, odour descriptions, complaint investigation procedures and technical information on suitable prevention, abatement and mitigation measures that can be used to avoid offensive odours.

What is odour?

The regulation of odour causing offense is one of the most difficult areas of our work due to the subjective nature of offense: what is offensive to one person may not be offensive to another and some people may be more sensitive to a particular odour than others. This section of the guidance describes odour from a scientific perspective and looks at different types of odour as well as the potential for the impact that offensive odour can have.

Dealing with new or changed facilities

This section provides guidance on assessing applications for new or changed facilities including the types of responses that would be appropriate at the planning consent stage, as well as determining applications for an environmental licence to operate. Advice is also given on undertaking assessments and on setting suitable conditions within environmental licences.

Regulating operational facilities

This section highlights the need for odour to be a regular topic for routine inspections and points to the technical appendices regarding appropriate control measures that should be employed by operators eg management, containment, abatement and discharge into the environment.

Responding to incidents and complaints

This section, with Appendix 3, uses the concept of Frequency, Intensity, Duration, Offensiveness and Location (FIDOL) to structure investigations into odour incidents and complaints. As mentioned above the assessment of offensive odour can be subjective so the use of FIDOL provides a helpful framework for officers to consider the offensiveness of any particular odour against.

This section also builds on our incident classification scheme to provide more detailed advice on dealing with incidents involving odour.

Please note that the guidance is designed to complement our Enforcement Policy by providing specific advice on offensive odour issues and does not in any way supersede or replace that policy.

Working with communities

This section highlights the importance of working together with affected communities to resolve issues. It is important to keep communities aware of actions taken to resolve issues, how long these actions may take and what should be achieved. This includes informal as well as formal action such as enforcement notices.

For many potentially offensive odours there are no simple measurements that can be applied to determine how much impact they have. This guidance provides the necessary information to our officers to undertake suitable and appropriate assessments as well as tools that can be used in the regulation of activities that could cause offensive odour.

To that end the guidance is a development to increase our effectiveness and to ensure our decision making with respect to odour can be undertaken in an appropriate and structured manner. The guidance cannot give a simple answer to every odour issue because each odour event is different and has to be considered in the circumstances applying at the time. Therefore this guidance must be read in conjunction with other SEPA guidance: on regulating emissions to air, such as Pollution Prevention Control and Waste regulationsour policies on enforcement and above all to our vision for regulation.