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Never Mix Drain Unblockers to Avoid Damaging Pipes or Even Injuries Unclear Product Information on Ingredients and Usage Consumers Should Choose with Care

  • 2023.05.15

Many households have been troubled by clogged drains and may attempt to clear them with drain unblockers purchased. However, as most of these products are corrosive, the wrong choice or improper use will not only undermine results, but might also damage pipes and even increase risks of accidental injury. The Consumer Council surveyed 17 common drain unblocker models on the market, analysed their key chemical ingredients and potential risks, and reviewed the scope of application and restrictions claimed by the various models. The Council reminds consumers that different drain unblockers contain varying active ingredients and might have disparate effects on different types of clogs, so it is necessary to read the list of ingredients carefully before use to achieve optimum results, yet 5 surveyed models did not list out the product ingredients. Besides, 4 models were found to not have safety warnings in both English and Chinese, whereas 8 models did not have instructions for use in both English and Chinese, all of which were referred to the Customs and Excise Department (C&ED) for follow-up. The Council reminds consumers to be extra cautious when using drain unblockers to avoid chemical burns, and to refrain from mixing different unblockers or cleaning agents to avoid producing toxic gases or even causing explosions. Consumers are recommended to first try tools such as plungers to clear blockage, and to develop diligent maintenance habits to prevent the build-up of clogs.

In March this year, the Council sourced 17 models of commonly available drain unblockers from various retailers, priced between about $10.0 and $79.9. The models included 6 in liquid form, 6 as powder, granules, or sticks, 3 gels and 2 foams. Estimating the amount to unclog a moderately clogged drain, according to the application methods indicated on the package, it would cost about $1.5 to $79.9 for each use, a difference of over 50 times.

Drain Unblocker Ingredients Varied

Select According to Different Nature of Clogs

Drain unblockers are generally used to break down or increase the solubility of clogs through chemical reactions, while the heat generated from chemical reaction could also help dissolve the blockage. The chemicals used in most drain unblockers are corrosive in nature, but their efficacy in breaking down different kinds of blockage varies.

Drains connecting to kitchen sinks are more likely to be clogged as a result of grease accumulated over time. Unblockers containing strong alkaline ingredients might have better performance in dissolving grease. Among all models, 11 were labelled as containing strong alkaline ingredients, usually sodium hydroxide, which is highly corrosive and could break down the molecular structure of the blockage and react with grease molecules to increase its solubility in water, effectively clearing clogs caused by grease.

Bathroom drains are usually clogged by hair. 11 models were labelled as containing oxidising agents such as sodium percarbonate or sodium hypochlorite, which are generally effective in breaking down the protein content of hair. In addition, 1 model was labelled as containing strong acid. These types of unblockers usually contain concentrated sulphuric acid, which could easily decompose organic fibres such as toilet paper and fabric. Since strong acids are extremely corrosive, improper handling could cause violent chemical reactions and are generally recommended for professional use only. Consumers should pay attention to the scope of application of these products, as 5 models in the survey were specified as not suitable for toilets.

Furthermore, 1 model was labelled with enzymes as the active ingredients. Although specific types of enzymes could be used to break down protein or grease, their reaction is often slower, requiring over 10 times longer than other chemical agents to clear clogs, and are sensitive to conditions such as the temperature and pH. Therefore, they might not be able to clear blockage problems immediately.

Improper Use Could Pose Safety Risks

Never Mix with Other Chemicals

The chemical nature of drain unblockers is powerful in dealing with clogs, but they might be hazardous to the user or pipes if handled improperly. Unblockers with strong alkalis or strong acids are highly corrosive and could cause severe chemical burns if splashed onto exposed areas such as the skin. Moreover, excessive amount of heat might be generated during the dilution or decomposition action of unblockers, which might boil the solution, causing the unblocker agent to splash out from drains or produce corrosive vapours that could burn the skin or respiratory tract. Besides, the heat generated during use might exceed the pipe’s threshold, resulting in softening and deformation of the pipe’s material. In such instances, the pipe junctions or soft plastic parts are particularly vulnerable, and might lead to leakage in serious cases. Consumers should not use unblockers with strong alkaline or strong acidic ingredients for metal piping to avoid eroding through the material.

Moreover, consumers should never mix drain unblockers or cleaning agents as this might produce toxic gases, which in severe cases might lead to explosions. In addition, some unblockers contain ingredients that might release toxic fumes (e.g. chlorine gas) when they come into contact with other chemicals (e.g. bleach). Years ago, there were incidents overseas where mixed use of different brands of drain unblockers caused death and injury, so consumers must be vigilant.

On the other hand, when pouring unblockers into drainage pipes, it might corrode the surface materials of wash basins, sinks and toilets. Among the surveyed models, 13 had labels warning against the use on certain metals (e.g. aluminium, brass), rubber or enamel, or else they might leave marks that are difficult to remove. With this in mind, consumers should pay heed to the usage guidelines.

Some Models Might Not Meet Labelling Requirements of the Consumer Goods Safety Regulation

Improper use of drain unblockers could be dangerous and consumers should understand the product information in detail before making a choice. 4 models in the survey did not list safety warnings in both English and Chinese, while 8 models did not have usage instructions in both English and Chinese, which might not be in compliance with the requirements of the Consumer Goods Safety Regulation. The products in question were referred to the C&ED for follow-up. In addition, 5 models did not list the product ingredients. Although Hong Kong legislation does not require such information to be labelled, traders have the responsibility to provide sufficient product information to consumers on the foreseeable hazards and proper use of their products. The Council urges relevant manufacturers to improve product information transparency.

On the other hand, some unblockers are packaged into individual packets resembling packaged sugar, salt, or instant noodles seasoning in appearance, which could cause grievous consequences if consumed inadvertently. According to the Hong Kong Poison Information Centre, in 2018, an elderly person who tried to treat low blood glucose level by consuming sugar, mistakenly mixed an individually packaged drain unblocker powder with water and drank it, resulting in chemical burns to the mouth, throat, oesophagus and stomach. 2 models in the survey were individually packaged. The Council reminds consumers to properly store unblocking products and caution their family members to avoid misuse.

Apart from using drain unblockers, consumers can also consider first using physical means such as a plunger to unclog drains. There are also “plumbing snake” or drain clog remover tools on the market that could reach into drains to extract clumps of hair. However, as the clogs extracted might contain bacteria and unpleasant odours, and spillage of sewage might also occur, consumers should take protective measures when unclogging drains. Furthermore, pipes previously treated with chemical unblockers should be flushed with plenty of water to ensure no residual chemicals remain before proceeding with other treatments.

Consumers should pay heed to the following when using drain unblockers:

  • It is advisable to purchase products with ingredients clearly labelled. Fully understand the properties and potential safety risks of the unblocker, strictly follow instructions for use, and do not guess or estimate the amount to be used or mix with other cleaning agents;
  • Take protective measures while using such products, such as wearing plastic gloves, goggles or glasses (do not wear contact lenses), a mask or face shield, etc. Do not use cotton workman gloves because not only is the surface material unable to prevent the unblocker from contacting the skin, but it could even absorb the chemicals and increase the duration and area of skin corrosion;
  • Ensure good ventilation to avoid accumulation of harmful gases or insufficient oxygen in the room where unblockers are used. Unless otherwise stated on the product packaging, siphon off any accumulated water before adding the unblocker;
  • If the skin is inadvertently splashed with drain unblocker, rinse immediately with plenty of water while avoiding the rinse water from flowing onto unaffected skin surfaces. Small areas of burns can be covered with a clean light dressing after adequate washing. For larger or more serious burns, seek medical attention as soon as possible after rinsing and if possible, bring along the unblocker packaging for reference by medical professionals;
  • Store unused or leftover drain unblocker in the original packaging of the product. Never use other containers to store unblockers to prevent erosion;
  • Avoid storing multiple drain unblockers and cleaners in the same place to avoid chemical reactions in case of leakage, and avoid storing excessive quantities of chemicals (including drain unblockers, cleaners, solvents, etc.) at home. Unblockers should not be stored for too long to avoid deterioration of chemical composition, which may affect the effectiveness and even be converted into harmful substances;
  • To reduce hair and food residue falling into drains, a filter should be installed at drain inlets, and avoid pouring excessive oil or thick soup into drains. After use, flush with ample hot water to reduce the chance of clogging problems caused by grease.

 

Download the article (Chinese only):  https://ccchoice.org/559drainunblockers

 

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