'Triclosan', considered harmful when exposed to high levels for a long time, is most likely present in which of the following?

Mentions using simple household sprays (turmeric solution, soap solution) for practical tasks, implying some agricultural/household treatments use natural or mild common substances rather than specialised antimicrobials.

A student could compare common ripening practices (household sprays vs commercial ripeners) or inspect ingredient lists of ripening sprays to see if antimicrobials like triclosan appear.

Explains that esters are used as flavouring agents in foods, linking fruit treatment to agents that affect smell/taste rather than antimicrobials.

One could check whether commercial ripening agents target flavour/aroma (esters/ethylene) rather than antimicrobial action, suggesting triclosan would be an unlikely choice.

Describes natural ripening due to climatic conditions (long sunny summer) in orchard farming, indicating ripening is often achieved environmentally rather than by applying chemical antimicrobials.

Use this to separate naturally-driven ripening from chemical ripening: survey common agricultural ripening methods (environmental control vs chemical treatments) to see where triclosan might fit.

Defines oxidising agents and gives examples (potassium permanganate, dichromate) used to change organic compounds, showing that specific classes of chemicals are used deliberately to alter fruit chemistry.

A student can infer that ripening agents are typically specific reactive chemicals (e.g., oxidisers or plant hormones) and therefore check whether triclosan (an antimicrobial) belongs to the chemical classes used for ripening.

Describes mixtures and their components, implying commercial formulations (ripening sprays) are mixtures whose ingredient lists can be analysed for presence/absence of compounds like triclosan.

One could inspect ingredient/mixture lists of ripening products or regulatory lists of permitted additives to see if triclosan is included.

Explicitly lists 'additives and plasticizers, fillers, flame retardants and pigments' as components of plastics, showing plastics commonly contain added chemicals.

A student could check whether triclosan is used as an additive/antimicrobial in consumer plastics or plastic coatings and therefore plausibly present in some containers.

States that 'plastic bags can also contaminate foodstuffs due to leaching of toxic dyes', establishing that chemicals in plastics can migrate into food.

Combine with knowledge that reused food-contact plastics experience repeated use/heat and test whether triclosan (if present) migrates into food under such conditions.

Notes that plastics contain harmful substances and that processes like burning release toxicants, indicating plastics can hold and release diverse chemicals.

Use this general rule — plastics can carry and release additives — to justify targeted analysis for triclosan in reused containers or their wash water.

Explains that plastics persist and degrade slowly (UV-induced photo-oxidative degradation is slower in some environments), implying additives can remain available to leach over time.

Combine with the fact that long-lived plastics retain additives to infer that triclosan, if incorporated, might still be present and capable of leaching after repeated use.

Describes engineered liners to prevent leaching from landfills, implying that leaching from plastics is a recognized pathway requiring containment.

A student can infer that because leaching is a known concern for plastics, testing reused containers for specific antimicrobials like triclosan is warranted.