Well, wet wipes are labelled as 'safe to flush', not because they're actually flushable, but because, since the mid-2000s, wet wipes have become more commonly used as alternative toilet people in affluent homes. They were labelled as flushable by manufacturers so as to encourage this use. But what exactly is it that makes wet wipes unflushable?

Well, wet wipes are produced as air-laid paper. This is where the fibres are carried and formed to the structure of paper by air or with nonwoven spun-lace fabric. The fibres are intermingled with hydro-entanglement through very high pressure of water. They are then moistened with water or other liquids based on their applications. They may be treated with softeners, lotions or perfumes. Preservatives are also used in order to prevent bacterial/fungal growth in the package. Air-laid paper forms clogs when flushed. And, because some of the ingredients in the wet wipes are highly lipophilic i.e. fat-loving, the wet wipes cling together with fats to form fatbergs. Clogs and fatbergs block internal plumbing, septic systems and public sewer systems. Additionally, alcohol-containing wipes kill the bacteria and enzymes responsible for breaking down solid wastes in septic tanks. Furthermore, wet wipes are non-biodegradable.

There have been very many incidences of fatbergs and clogs in many different cities around the world. So much so that there are several cities that are currently suing wet wipe manufacturing companies for labelling their products 'flushable' when they're clearly not. For instance, in April 2015, a 40-metre long fatberg was reported as having been removed from underneath Chelsea. The damage inflicted by the fatberg was estimated to cost about 400,000 British pounds to repair and took two months to remove. In January 2016, the Eleeban sewage pumping station was damaged as a result of a blockage from a fatberg that weighed about a tonne and took about 4 hours to remove by crane. There are numerous ongoing petitions by water firms, city councils and environmentalists calling for wet wipe manufacturers to remove the 'safe to flush' labels ad replace them with 'do not flush' labels. The proper way to dispose of wet wipes is to throw them in the trash, in the non-biodegradable section.

Other things that should never be flushed down the toilet include condoms, pills, cotton balls, cotton swabs, sanitary pads, tampons, paper towels, cigarette butts, band-aids, dental floss, cat litter and disposable diapers. Also, avoid pouring fats, oils and grease down the drain or garbage disposal.

1. Wikipedia.