Every country has its own regulation which rules the waste disposal to the drain. Why should chemicals not be released in drain? Negligence of these rules will bring much harm and less benefit. Keep in mind to ask your environmental safety officer for comprehensive list of chemicals which can go down to the drain.
The harmful effects of chemical waste are corrosive and toxic. Otherwise, these materials can be sent down to the drain because it has been considered safe based on the research. Why? Because these materials readily ingestible by the microorganism in a water treatment plant.
Here are several lists of organic chemicals which can go down the drain if they meet all the following criteria.
Nonhazardous category means there is no radioactive waste, no hazardous chemical waste, and no untreated biohazardous waste. Nonhazardous waste has a low toxicity and even high water solubility.
Biohazardous waste can be disposed after treated by decontaminating the waste. There are two following methods of decontamination which are suitable for these waste’s drain disposal.
- Deactivating it with the bleach (1 part bleach to 9 parts liquid waste) for 30 minutes before going it down to the drain
- Occasionally, liquid waste is autoclaved. These substances shouldn’t be added the bleach before being autoclaved.
Radioactive chemical list is a list of substances which has an ability to emits radioactive rays more than 0,002 µCi per gram. Radioactive waste which is water soluble and dispersible in water could be disposed down to the drain unless the concentration is less than 200 µCi per laboratory per day. Please keep in mind to maintain Radioactive Material Usage Log for this waste’s disposal record.
This category means there is no solid, muddy, or viscous substances.
- Hot liquid which non hazard with temperature more than 150°F. You can dispose hot liquid if the volume less than 10 gallons.
- The grease and oily substances can also be poured down to the drain unless the concentration is less than 500 mg per liter.
- Rinse water should not be poured down to the drain unless it hasn’t been contaminated by hazardous materials such as acidic and toxic cleaning solutions.
- Hydrogen peroxide could be poured down to the drain if the concentration is less than 8%.
- Formalin and formaldehyde unless the concentration is nonhazardous and equal with less than 2.9% formaldehyde. Furthermore, formalin and formaldehyde which don’t contain any methanol or other hazardous chemicals.
- Chemicals which can be safely disposed down to the drain including biological compounds and cellular constituents such as proteins, nucleic acids, carbohydrates, sugars, amino acids, amines, nutrients, surfactants, and many metabolic intermediates.
- No interfering with sewage treatment operations. Sanitary sewer means the system of sinks, toilets, drains, and associated pipes which send the waste water to a treatment plant.
Here are several examples of chemicals which are considered safe for drain disposal.
- Dilute solutions of inorganic salts including both cations and anions which are listed in the following table.
Why? These materials are relatively low in toxicity. Any compounds with these ions which are strongly acidic or basic should be neutralized before removing it down to the drain. The examples of inorganic salts are including drying agents, such as calcium chloride, magnesium sulfate, sodium sulfate.
Corrosive waste with a pH between 2 to 5 could be disposed down to the drain after the pH has been adjusted. It can be done by 2 following options: (a) The pH is adjusted to greater than 5 and less than 12.5 or neutralized to pH 5.5 – 9 range, in order to be disposed down the drain; (b) Non-adjusted waste should be stored and disposed as hazardous chemical waste. Any other chemical compound which is low toxicity and low molecular weight biodegradable organic chemicals such as aldehydes, ketones, amines, ethers, nitriles, esters, and nitroalkanes.
- The material organics which quantities are below or up to about 10 g or 100 ml at a time are proper to be disposed down to the drain while flushing with excess water. These materials are readily water soluble at least 3 percent, which present low toxicity hazard and biodegradable.
- Alkanol with 4 or fewer carbon atoms, such as methanol, ethanol, propanol and isomers, butanol and its isomers. Moreover, alcohol containing salts (from destructing sodium) is also water soluble waste which can be considered safe. Alcohol can also be gone down to the drain unless the concentration is nonhazardous, which is less than 24%.
- Hypochlorite solutions, from destroying cyanides and phosphines
- All disinfectant solutions used to inactivate Hazard Groups 1 and 2 biological agents.
- Specific organic chemicals which concentration of one percent or less, which are.
- Alkanediols with 7 or fewer carbon atoms, such as butanediol and isomers, ethylene glycol, heptanediol and itsisomers, hexylene glycol, pentylene glycol, butylene glycol, heptamethylene glycol, hexanediol and its isomers, pentanediol and its isomers, and propylene glycol.
- Sugars and sugar alcohols (polyols), such as dithioerythritol, glycerol, mannitol, xylitol, dithiothreitol, lactitol, molasses, erythritol, maltitol, and sorbitol.
- Alkoxyalkanols with 6 or fewer carbon atoms, such as butoxyethanol, ethyoxyethanol, and methoxyethanol.
- Aliphatic aldehydes with 4 or fewer carbon atoms, such as acetaldehyde, butyraldehyde (butanal), formaldehyde, glutaraldehyde, isobutyraldehyde, propionaldehyde (propanal).
- Aliphatic amines with 6 or fewer carbon atoms, such as amylamine, dimethylpropylamine, hexylamine, methylamine, N-ethylmethylamine, iso-amylamine, isobutylamine, ethylamine, isobutylamine, methylbutylamine, N-methylpropylamine, diethylamine, butylamine, 1-etjhylpropylamine, isopropylamine, N-ethylbutylamine, and trimethylamine.
- Nitriles, such as acetonitrile, butyronitrile, isobutylnitrile, and propionitrile.
- Sulfonic acids and sodium and potassium salts of the acids.
- Specific examples of inorganic chemistry in everyday life, which concentration of one percent or less
How Much May be Disposed?
Quantities of chemical waste for drain disposal should be limited to a few hundred grams or milliliters or less per day. Larger amounts should have approval first from environmental safety department. The quantities which are considered safe are up to 100 grams or 100 milliliters per discharge. This disposal should be followed by flushing with at least 100-fold excess of water per disposal.
The properties of all these materials can be understood by reading the material safety data sheet (MSDS). Furthermore, if you have any doubt whether a solution can go down to the drain, please contact environmental department officer for further questions.