Public Analysts are scientists in the United Kingdom and Ireland whose principal task is to ensure the safety and correct description of food by testing for compliance with legislation. Most Public Analysts are also Agricultural Analysts who carry out similar work on animal feedingstuffs and fertilisers.  While much of the work is done by other scientists and technicians in the laboratory, the Public Analyst has legal responsibility for the accuracy of the work and the validity of any opinion expressed on the results reported. There is an Association of Public Analysts, which includes members with similar roles if different titles in other countries.
The office of Public Analyst was established in 1860, with the Act for Preventing the Adulteration of Articles of Food and Drink, the first three appointments being in London, Birmingham and Dublin. Since the separation of the UK and Ireland, they operate under different legislation, but the term and general duties are the same. The original work was chemical testing, and this is still a major part, but nowadays microbiological examination of food is an important activity, particularly in Scotland, where Public Analyst laboratories also carry out a statutory Food Examiner role.
The primary UK legislation is the Food Safety Act 1990. All local authorities are required to appoint a Public Analyst, although there have always been fewer Public Analysts and their laboratories than local authorities, most being shared by a number of local authorities. On the UK mainland there has always been a mixture of public sector and private sector laboratories. This remains the case today - but they all provide an equivalent service, and avoidance of conflicts of interest are ensured by the statutory terms of appointment. There is a statutory qualification requirement for Public Analysts, known as the Mastership in Chemical Analysis (MChemA), awarded by the Royal Society of Chemistry. This is a specialist postgraduate qualification by examination that verifies knowledge and understanding of food and its potential defects, interpretation of food law, and the application and interpretation of chemical analysis for food law enforcement.
In the mid 1980s there were some 40 Public Analyst Laboratories in the UK with over 100 appointed Public Analysts. By 1993 that had reduced to 34 Laboratories and around 80 Public Analysts, and by 2010 the number of Public Analyst Laboratories in the UK had reduced to 22 with only about 26 Public Analysts.
Enforcement of food law in the UK is by local authorities, principally their environmental health officers and trading standards officers. Whilst these officers are empowered to take samples of food, the actual assessment in terms of chemical analysis or microbiological examination and subsequent interpretation that are necessary to determine whether a food complies with legislation is carried out by Public Analysts and Food Examiners respectively, scientists whose qualifications and experience are specified by regulations.
The Public Analyst runs a laboratory which will:
- Analyse food:
- for composition: many foods have legally defined, customary or expected compositions
- for additives: which must be legally permitted and within prescribed concentrations
- for contamination: chemical, microbiological
- to assess the accuracy of labelling
- to investigate whether complaints by the public are justified
- Interpret relevant law passed by the EU and UK or Ireland:
- act as expert witness in prosecutions
In addition to their central rôle in relation to food law enforcement, Public Analysts provide expert scientific support to local authorities and the private sector in various other areas, for example they:
- analyse drinking, bathing water including swimming pools, industrial effluents, industrial process waters and other waters
- investigate environmental products and processes including assessing land contamination, building materials and examining fuels
- advise on waste management
- investigate and monitor air pollution
- advise on consumer safety - in particular consumer products such as toys
- monitor asbestos and other hazards
- carry out toxicological work to assist HM Coroners
Sampling is largely outside the control of the Public Analyst.
Local authorities have a duty to check the safety of food and to provide adequate protection of the consumer. To achieve that they devise sampling plans, seeking to balance their need to monitor food against limited resources and other demands on their budgets. A typical sampling plan for a local authority might include samples of the following:
- samples from a particular source - a supermarket, manufacturer or caterer or country
- meat products - to check %meat or %fat or non-meat or additives or species
- product marketing claims
- undeclared ingredients in prepared foods
- contaminated products
- nutritional content of prepared meals
- Public Analyst's Laboratory, Dublin
- The Public Analyst Service
- Association of Public Analysts
- Statutory Instrument 1990 No. 2463 The Food Safety (Sampling and Qualifications) Regulations 1990
- International Standard ISO/IEC 17025:2005 - General requirements for the competence of testing and calibration laboratories BSI