**Acknowledgements**

*Aflatoxin B1 Occurrence, Detection and Toxicological Effects*

The World Health Organization, in collaboration with the Food and Agriculture Organization, is responsible for assessing the risks to humans caused by mycotoxins through contamination in food and for recommending adequate maximum levels in food and feed. Risk assessments of mycotoxins in food done by the Joint FAO/WHO Expert Committee on Food Additives are used by governments and by the Codex Alimentarius Commission (the intergovernmental standard-setting body for food) to establish maximum levels in food and provide other risk management advice to control or prevent contamination [11]. The outcome of such health risk assessments can either be a maximum tolerable intake (exposure) level or other guidance to indicate the level of health concern (such as the margin of exposure), including advice on risk management measures to prevent and control contamination and on analytical methods and monitoring and control activities [25]. These tolerable daily intakes are used by governments and international risk managers, such as the Codex Alimentarius Commission, to establish maximum levels for mycotoxins in food [11]. The maximum levels for mycotoxins in food are very low due to their severe toxicity. For example, the maximum levels for total aflatoxins set by the Codex in various nuts, grains, dried figs and milk are in the range of 0.5–10 μg/kg [24]. The WHO encourages national authorities to monitor and ensure that levels of mycotoxins in foodstuff on their market are as low as possible and comply with the both national

and international maximum levels, conditions and legislation [25].

menace, has caused problem of food insecurity in the past.

Aflatoxicosis cases are very common in Kenya, and the major cause is contaminated maize and maize flour. The total aflatoxin and AFB1 levels that have been obtained in maize grains and maize flour are indicating that commercial milling

Different countries and authorities worldwide have rules and regulations governing aflatoxin B1 in foods which include the maximum permissible levels and recommended levels for certain foods. The Kenya Bureau of Standards (KEBS) has adopted the broad Codex standard limits of 5 ppb (for single metabolite) and 10 ppb for total aflatoxins in food but does not have lower limits for sensitive foods such as milk. The US Food and Drug Administration (FDA) had given an action level (maximum permissible) of total aflatoxin (B1) in combination with B2, G1 and G2 in foods as 20 μg/kg above in which the commodity is withdrawn from the markets [59], except milk which has a maximum level of 0.5 ppb. The Food Standards Agency has set a legal limit of total aflatoxins in foods as 10 μg/kg. Higher levels of 100–300 μg/kg are tolerable for some animal feeds. The EU has set maximum permitted levels for aflatoxin B1 in nuts, dried fruits, cereals and spices ranging from 2 to 12 μg/kg, while the maximum permitted level for aflatoxin B1 in infant foods is set at 0.1 μg/kg [119]. The maximum permitted levels for aflatoxin B1 in animal feeds set by the EU range from 5 to 50 μg/kg, and these levels are much lower than those set in the USA [120]. The Joint FAO/WHO Expert Committee on Food Additives has set the maximum permitted total aflatoxin level of AFB1 in combination with the other aflatoxins (B2, G1 and G2) at 15 μg/kg in raw peanuts and 10 μg/kg in processed peanut, while the tolerance level of aflatoxin B1 alone is 5 μg/kg for dairy cattle feed [121, 124, 125]. Results from previous studies have however shown that it is difficult if not impossible to eradicate AFB1 in cereals once produced [26]. For that matter, consumers are left vulnerable to exposure, yet burning of contaminated cereals, one of the most feasible ways of containing the

**7. Aflatoxin B1 regulation in Kenya**

**26**

**8. Conclusions**

The authors wish to thank the National Research Fund (NRF), Nairobi, Kenya, through a multidisciplinary TUK/MMUST/Maseno/PCPB research grant.
