FOOD SAFETY IN HORTICULTURAL CHAIN: The current issue of food safety has created great impacts on the consumers’ purchase behavior of food. Many consumers simply stopped buying certain types of fruits and vegetables. Many of them purchase fruits and vegetables very cautiously. The consequent less intake of fruits and vegetables may further worsen the malnutrition situation in the country. Safety related issue should be handled with utmost care by the all corners. Food may not be safe due to various reasons like adverse weather conditions, inappropriate handling, inappropriate use of agrochemicals and so on. The present food safety issues in Bangladesh are mainly concerned with food-borne illness; use of non-recommended agrochemicals (pesticides, PGRs, ripening agents, etc.); and paucity of technical experts in the detection and assessment of food adulteration. There is also lack of sufficient national standards to measure food safety and lack effective institutional mechanism to enforce food safety at different stages in the food chain. Continued research to develop easy to use practical testing kits to identify chemicals, pesticides, additives, preservatives, toxic elements, etc. at the production, processing, distribution and consumption levels is essential. To go along with the increasingly important food safety requirements for high-value products, investments are needed in laboratory and testing infrastructures to make them compatible with international standards. HEAVY METALS: Presence of heavy metals, namely arsenic (As), lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr), etc. in food, is one of the important threats related to food safety. The extent to which the population of Bangladesh is exposed to food contamination by toxic heavy metals is not widely available. It is apprehended that rice and vegetables used in the daily diets might have elevated levels of heavy metals (Islam et al. 2009; Jahiruddin et al. 2009). The possible sources for heavy metals in food include: contaminated waters and soils; inadequately composted manures (e.g. poultry manure); pollution of water bodies with industry wastes, and so on. Research reports related to the presence of heavy metals in edible fruits and vegetables are meager in Bangladesh. Nonetheless, Naser et al. (2011) examined the levels of heavy metals in some leafy vegetables, namely spinach, red amaranth and amaranth. When the samples of spinach, red amaranth and amaranth were analyzed the levels of cadmium (0.58, 0.34 and 0.48 µg g-1, respectively) and chromium (6.20, 5.70 and 4.81 µg g-1, respectively) were found higher than the maximum allowable limits set by the World Health Organization (WHO). As per the WHO the allowable levels of Pb, Cd, Ni and Cr are 2.0, 0.02, 10.0 and 1.30 µg g-1, respectively (Lone et al. 2003). However, the levels obtained in the present study were lower than the maximum allowable limits as set by the Prevention of Food Adulteration Act (PFA) 1954, India (2.5, 1.5, 5.0 and 20.0 µg g-1 for Pb, Cd, Ni and Cr, respectively) (Lokeswari and Chandrappa 2006). Islam et al. (2013) reported that 94% males from the poor households and 78% males from the non-poor households had Cd intake above maximum permissible limit (50 µg day-1 60 kg body weight-1). The report also indicated that both the poor and non-poor households of the selected areas of Bangladesh had high intakes of As and Pb from different foods and are at potential risk from As and Pb contamination. MICROBIAL CONTAMINATION Another type of contamination is the microbial contamination of food like fruits, vegetables, street vending food, semi-processed and processed food, salad, etc. due to various microorganisms. Microbial contaminations due to negligence would include typhoid (Salmonella), dysentery (Shiegella), food poisoning (Staphylococci), botulism (Clostridium botulinum) and aflatoxin (Aspergillus flavus). The important reasons for microbial contamination include: contaminated inputs (soil, water, fertilizers, etc.), poor and unhygienic postharvest handling of food commodities, preparation of food in unhygienic conditions, use of poor quality ingredients for the food preparation, and lack of personal hygiene during food handling and food preparation. For example, it is worth to mention the recent food borne illness caused by the consumption of fresh watermelon in the Kushtia and Manikganj districts of Bangladesh, where several people died and dozen fell sick after eating watermelon. Initially, it was suspected that contamination would have occurred due to the use of colouring agent into the fruit to brighten the pulp (Anon. 2014a). PESTICIDE RESIDUES: There exists various human-induced food adulteration during farm and industrial production and marketing. One of the important human-induced safety concerns is the presence of pesticide residues in food, which is possibly resulted from the use of non-recommended pesticides; use of overdoses of pesticides; application of pesticides at shorter intervals; non-compliance to the withholding period (minimum duration between last application and harvest); application of cocktail of pesticides; ignorance of the users; lack of motivation; lack of proper and adequate media campaign; and exploitation by the agents of the pesticide suppliers. For instance, growers of brinjal in Bangladesh apply pesticides to control different pests and diseases. The growers often use insecticides and fungicides along with PGRs as cocktail. The major insecticides for controlling brinjal pests are of Cypermethrin (Superthion) and Dimethoate (Tafgor 40EC) groups, whereas the major fungicides are Dithane M-45, Thiovit, Minicaper and Redomil (Hassan et al. 2010). Consumers are reluctant to buy chemical-sprayed fruit and vegetables to avoid health risks. RIPENING CHEMICALS Bangladesh is facing another typical problem of using synthetic chemicals (calcium carbide and ethephon) in accelerating ripening of climacteric fruits like mango, banana, papaya, tomato and jackfruit. Some non-climacteric fruits like pineapples are also being exposed to ripening chemicals. Calcium carbide is banned and ethephon-based formulations are not recommended for fruit ripening in Bangladesh. Actually, for commercial agriculture accelerated fruit ripening is recommended all over the world for uniform ripening, taste and quality and to facilitate marketing. In the developed country ethylene gas is used to accelerate ripening of climacteric fruits (Wills et al. 2004). This is healthy, and it does not pose any threat to human health. By contrast, in Bangladesh, different types of liquid plant growth regulators, namely Harvest, Profit, Tomtom, Ripen, etc. containing ethephon as active ingredient are sprayed on the fruits or the fruits are dipped into the solution of ripening chemicals (Hassan 2010; Hassan et al. 2010, Whahid et al. 2011). These chemical formulations are not recommended for fruit ripening in Bangladesh but being used by the growers and traders since there are no alternatives. Growers often use these chemicals at higher doses as compared to the dose mentioned on the label. An experiment was undertaken by Whahid et al. (2011) to examine the effects of concentrations of these ripening agents (although not recommended) on the rate of ripening. Results suggested that the concentration mentioned on the label (1 ml L-1) had the same rate of ripening as that of the half of the concentration (0.5 mL L-1).