Charcoal Odour Absorber

Details

Steam-activated coconut-shell carbon in a breathable undyed cotton bag, for a fridge, a shoe rack, a wardrobe or a car. It works by physical adsorption, meaning odour molecules stick inside the pores of the carbon, and everything true about this product follows from that one fact. The first thing it means is that surface area is the whole product, and it is never printed. Ours is 1050 square metres per gram by nitrogen adsorption, with an iodine number of 1000 mg per gram measured by the method in IS 877. That matters because a great many charcoal odour bags on sale are carbonised, not steam-activated, which is a different and much cheaper process that leaves a fraction of the pore structure, and since nobody publishes an iodine number there is no way to tell a real adsorbent from ground barbecue charcoal in a cloth bag. The second thing it means, and this is the one we are going to contradict the whole category on, is that the capacity is finite and it does not come back. Activated carbon holds roughly ten to thirty percent of its own weight in adsorbed organics and then it is full. Putting the bag in direct sun for a few hours is a claim made on almost every pack in this category, and it is only a quarter true: a few hours outdoors brings the bag to perhaps 55 or 60 C, which drives off adsorbed water and genuinely restores its damp-control ability, and does very little to the organic molecules that cause smell. Real thermal regeneration of activated carbon needs 150 C and upwards, usually with steam, and it is an industrial process. So sun it monthly for damp if you like. Do not expect two years of odour control out of it, and we do not claim any.

• Steam-activated coconut-shell carbon. Surface area 1050 m2/g, iodine number 1000 mg/g to IS 877, both measured per lot
• Capacity is finite: about 20 to 60 g of adsorbed organics for a 200 g bag, and then it is done
• Replacement interval, stated honestly: the 75 g bag at four months in a fridge of about 250 litres or a shoe rack, the 200 g bag at six months in a wardrobe or a car cabin
• It does not work in an open room. A 200 g bag in a normal bedroom does nothing measurable, because an open room exchanges its air far faster than a passive bag can adsorb, and passive carbon only works in an enclosed low-airflow volume. That is the limit the category never states
• Nothing else in the bag. No fragrance, no gel, no plastic pod, no battery, no dye. Carbon in undyed cotton with a cotton loop
• Fully passive, so it costs nothing to run, sprays nothing into the air and cannot be over-used
• Safe inside a fridge with food. It adds no smell, it removes one, and there is nothing in it to migrate
• At the end, cut the bag open and dig the carbon into a plant pot or a compost pit, where it holds water and improves soil structure. The cotton bag composts as well, so none of this becomes waste