SAFEGUARDS | Food NO. 153/15

SafeGuardS shellfish

The Government of India’s (GOI) Food Safety and Standard Authority of India (FSSAI) has amended the Food Safety and Standard Regulation 2011, by publishing limits for biotoxins in bivalve molluscs. Objections and requests for hearing must be received before September 4, 2015.  

Biotoxins are secondary metabolites produced by several microalgal species ranging from dinoflagella to diatoms, and even cyanobacteria, when these organisms rapidly multiply and produce blooms. Shellfish accumulate these toxins when grazing. Shellfish, especially mussels, scallops, oysters and clams are major vectors for transferring biotoxins that result in human intoxication. Human consumption of contaminated shellfish can lead to different types of toxic syndrome which have attracted scientific attention in recent years. Based on these syndromes, biotoxins have been classified into six groups. The toxins in each group and the affected seafoods are shown in Table 1.

Table 1: Classification of biotoxins based on toxic syndromes, type of toxin, and the affected seafood

Toxic syndrome

Type of toxin

Affected seafood

Paralytic shellfish poisoning (PSP)

Saxitoxin (STX), Neosaxitoxin Gonyautoxins (GTXs), and their analogues


Amnesic shellfish poisoning (ASP)

Domoic acid and its analogues

Shellfish, finfish

Diarrheic shellfish poisoning (DSP)

Okadaic acid (OA), Dinophysistoxins (DTXs), Pectenotoxins (PTXs), Yessotoxins (YTXs)


Azaspiracid shellfish poison (AZP)

Azaspiracids (AZAs)


Neurotoxic shellfish poison (NSP)

Brevetoxins (PbTx)

Shellfish, finfish

Ciguatera poisoning

Ciguatoxins (CTXs)


The mouse bioassay has been used as the official method to determine biotoxins in seafood in many countries, even though it has proven accuracy issues, low sample rates, and is time and labor intensive. With animal welfare in mind, new analytical methods have been developed, including Enzyme-linked immunosorbent assay and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Currently, food safety issues associated with biotoxins are placing greater responsibility on food producers, but regulations are limited to the European Union, United States of America and Japan. To comply with international regulations, the Indian government has proposed to set the limit of biotoxins in shellfish [1] by amending regulation F. No.2-15015/30/20, the details of which appear in Table 2. 

Table 2: Indian regulatory limits of biotoxins in shellfish

Sl. No

Name of the contaminant




Paralytic shellfish poison (PSP)

Bivalve molluscs

80 µg/100 g

(Saxitoxin equivalent)


Amnesic shellfish poison (ASP)

Bivalve molluscs

20 µg/g

(Domoic acid equivalent)


Diarrheic shellfish poison (DSP)

Bivalve molluscs

160 µg/kg

(Okadaic acid equivalent)


Azaspiracid shellfish poison (AZP)

Bivalve molluscs

160 µg/kg

(Azaspiracid equivalent)


Brevetoxin (BTX)

Bivalve molluscs

20 mouse unit/100g

or equivalent

The food supply chain needs to take no immediate action, however, objections and requests for hearing must be received before September 4, 2015. Once the draft amendment, and its biotoxins limits, become law, seafood producers and processors will need to implement an effective seafood testing programme.

SGS is committed to keeping you informed of regulation news and developments. Leveraging our global network of laboratories and food experts, SGS provides a comprehensive range of food safety and quality solutions, including analytical tests, audits, certifications, inspections, and technical support. We continually invest in our testing, capability, and state-of-the art technology to help you reduce risk, improve food safety and quality. For further more information, please visit SGS Food Safety website.

For enquiries, please contact:

Amornpun Dajsiripun
GCSC Food Specialist- Global Competence Support Center
t: +66 2683 0541 ext 2423

© SGS Group Management SA – 2015– All rights reserved - SGS is a registered trademark of SGS Group Management SA. This is a publication of SGS, except for 3rd parties’ contents submitted or licensed for use by SGS. SGS neither endorses nor disapproves said 3rd parties contents. This publication is intended to provide technical information and shall not be considered an exhaustive treatment of any subject treated. It is strictly educational and does not replace any legal requirements or applicable regulations. It is not intended to constitute consulting or professional advice. The information contained herein is provided “as is” and SGS does not warrant that it will be error-free or will meet any particular criteria of performance or quality. Do not quote or refer any information herein without SGS’s prior written consent.