How the SBS gained accreditation status for histamine analysis |06 April 2018

Histamine is a naturally occurring substance that can be found in our bodies and ubiquitously throughout the animal kingdom, as well as in some plants and bacteria. Histamine is involved in our local immune response to pathogens and allergens. It plays a central role in causing many of the symptoms of allergies such as inflammation and itching.

In certain fish, particularly in the families Scombridae and Scomberesocidae, such as tuna, mahi-mahi (Dorado) and marlin, high levels of histamine can form due to time and temperature abuse. It is imperative to keep fish at a temperature below 4.4°C or less as soon as possible after harvest since certain bacteria in the flesh of the fish can stimulate the formation of high levels of histamine which may lead to histamine poisoning.

Symptoms of histamine poisoning include tingling or burning in and around the mouth or throat; rash or hives on the upper body; drop in blood pressure; headache; dizziness; itching of the skin; nausea; vomiting; diarrhoea; asthmatic-like constriction of the air passage; heart palpitation; and respiratory distress. Symptoms usually occur within a few minutes to a few hours of consumption and last from 12 hours to a few days.

The Seychelles Bureau of Standards (SBS) last week announced that the regulatory agency had obtained accreditation for the testing of histamine in fish. The manager of the Biochemical Testing Services (BTS) and deputy chief executive at the SBS, Sreekala Nair, shares details on how the organisation was conferred accreditation status for histamine analysis.

Q: Why did the Food Chemistry Laboratory (histamine testing lab) need to be accredited?

A: The Food Chemistry Laboratory (FCL) at the SBS is the official testing laboratory for the Competent Authority (Fish Inspection and Quality Control Unit) for the testing of fish and fish products which are exported to the European Union (EU). It is a requirement of the EU Directive that the fish and fish products exported to the EU are tested in an accredited laboratory. It is to meet this requirement that the FCL had to achieve accreditation.

Q: What pre-requisites were required to be in place for the accreditation?

A: The laboratory should meet the requirements of the ISO/IEC 17025 - General Requirements for the Competence of Testing and Calibration Laboratories which is an International Standard developed by the International Organisation for Standardisation and International Electro-technical Commission.This includes having a management system according to the standard and meeting technical requirements of the standard.

In brief, procedures used need to be documented, internal audits need to be carried out regularly, management review meetings need to be conducted, test methods used for analysis need to be validated and measurement uncertainty estimated, competence of staff declared and participation of staff in Proficiency Test programmes etc.

Q: What technical trainings are given to the staff of the FCL to develop their competency for testing/accreditation?

A: Training given includes training on operation of High Performance Liquid Chromatography (HPLC), training on method validation and uncertainty estimation, training on requirements of the ISO/IEC 17025 standard and attachment to overseas accredited laboratories. Individual and team effort, dedication and hard work also is a reason for competence.

Q: How does the HPLC machine/equipment detect histamine in fish?

A: Histamine is extracted from fish and fisheries products as a solute after acid precipitation by perchloric acid of the insoluble protein. After the addition of buffers, they are derivatised by dansylation with dansyl chloride which reacts with proteins to form dansylated amino acid rendering them visible under Ultra Violet (UV) light. To stop reaction, ammonium hydroxide is added. Histamine is then separated from other biogenic amines and detected by ultraviolet-visible detector at wavelength of 245 nanometre (nm) and quantified.

Q: What data was gathered to demonstrate testing competency?

A: Testing competency was established mainly using Proficiency Test (PT) results by participating in Proficiency Test programmes and using Quality Control data by running Certified Reference Material (CRM’s)/Quality Control Material. Satisfactory Proficiency Test results and Quality Control values within acceptable range demonstrate competence to carry out test.

Q: Who is the accreditation body? How long was the assessment period and what challenges were faced during this time?

A: Southern African Development Community Accreditation Service (SADCAS) is the Accreditation Body. As we do not have a national Accreditation Body and as we are a member state of the Southern African Development Community (SADC), we are making use of the services of the regional Accreditation Body SADCAS.

Assessment is only for one or two days. After assessment, we have to submit Corrective Action for any non-conformance raised during assessment in the space of one month. Once the non-conformances are cleared, the Approvals Committee of the Accreditation Body takes the accreditation decision and the Accreditation Body notifies this decision to the organisation. Effective implementation of corrective actions was a little challenging.

Q: Is SBS planning any technical changes in the way histamine is currently being analysed in fish?

A: Histamine analysis using HPLC is a reliable and EU recommended method. We do not have plans to change the test method or the equipment whereas we are planning to buy one more HPLC to meet the demands for tests.

Q: Is SBS planning to get any new tests accredited?

A: The Chemical Analysis Laboratory is in the process of accrediting tests for coconut oil to support the local businesses in accessing the export market. The laboratory is validating test methods and estimating uncertainty associated with measurement for coconut oil tests. The Microbiology Laboratory will also start work from next year to accredit some microbiological tests performed in water.

The Environment Laboratory is the first testing laboratory in the country which was accredited. Accreditation was achieved for seven tests (pH, Conductivity, Nitrate, Nitrite, Sulphate, Chloride and Fluoride) in water in the year 2011 and extended the scope of accreditation in the year 2016 by achieving accreditation for three more tests (Mercury, Lead and Cadmium) in fish.

Reference: FDA - Fish and Fishery Products Hazards and Controls Guidance