General Information

Research and instruction in laboratories continually produce small amounts of aqueous wastes. In such cases, laboratory workers must decide whether to pour particular solutions down the drain or keep them for pick-up by REHS personnel. This guide will help them make such decisions.

Typically, unwanted chemicals are collected by REHS for disposal. This is done in accordance with Section A. "Policy for the Disposal of Chemicals." Certain materials are suitable for drain disposal. These should be carefully considered to ensure they do not cause damage to the plumbing system or cause other problems such as odors in a building.

The materials, which are suitable for drain disposal, are listed in the tables that follow. Other materials are prohibited from drain disposal without prior approval from REHS.

If you have questions about the suitability of other materials for drain disposal, or about the proper disposal of any laboratory material, please contact REHS at (732) 445-2550.

Drain disposal of dilute Acids and Alkalis

Acids and alkalis, which have been rendered neutral by the experimental process, may be discarded by drain disposal. Neutralization should be done in small quantities (i.e. no larger than 1 liter). This should be done as part of the experiment generating the waste.

It is inappropriate to collect a quantity of waste, from multiple experiments, and conduct batch neutralization process.
Proper care must be taken to adjust solutions to a pH of between 6 and 9. Generally, 1N hydrochloric acid can be used to neutralize alkaline materials and 1N sodium hydroxide can be used to neutralize acid materials.

When creating these 1N solutions, remember to SLOWLY add the acid to the water or the alkali to the water, not vice versa.

Safe Use Guidelines
  • Protective gear (gloves, laboratory apron, and safety goggles) must be worn.
  • Before pouring the solution, turn on the tap to get a good flow of water to wash it down. Make sure that the sink and drain lines are washed free of any substances that will generate noxious gases when mixed with the solutions. These substances include cyanides, sulfides, bisulfides, sulfites, bisulfites, nitrates, and nitrites.
  • Pour the solution down the drain slowly, making sure that before, during and after pouring, the tap is turned on to provide a strong flow of water that aids in washing it down the drain.
The following are drain disposable materials:

The following are drain disposable materials:

Solutions Adjusted to a pH of 6 to 9                                                                              Polyhydrox - Alchohols

Hydrobromic acid Sodium hydroxide 1,2-Propylene glycol
Hydrochloric acid Potassium hydroxide Glycerol (glycerine)
Hydriodic acid Ammonium hydroxide Mannitol
Nitric acid Potassium carbonate (potash) Sorbitol
Phosphoric acid Sodium carbonate (soda ash)  
Phosphorous acid Sodium pyrophosphate  
Sulfuric acid Trisodium phosphate  
Acetic acid    
Formic acid    


All Vitamins All Naturally Occuring Amino Acids All Sugars
L(+)-Ascorbic acid (Vitamin C) Alanine Arabinose
Choline Cysteine Fructose
Inositol Glycine Galactose
Nicotinic acid (niacin) Histidine Glucose
Pantothenic acid Leucine Lactose
Pyridoxine (Vitamin B6) Lysine Maltose
Riboflavin (Vitamin B2) Serine Sucrose
Thiamine (Vitamin B1) Tryptophan  


Chemicals* Commonly Used on the Farm and in the Household
(No pesticides of any kind)
Acetylsalicylic acid (aspirin) Casein Sodium bicarbonate
Alum (Sodium aluminum sulfate) Citric acid (sour salt) Sodium bisulfate
Ammonium alum (Ammonium aluminum
Corn syrup Sodium bitartrate
Borax (sodium tetra-Borate decahydrate) Dextrin Sodium carboxy-methylcellulose
Boric acid Gelatin Sodium chloride
Calcium chloride Magnesium sulfate (Epsom salt) Sodium citrate
Calcium phosphate, monobasic Potassium aluminum sulfate (potassium alum) Sodium dihydrogen phosphate
Calcium superphosphate Potassium bitartrate (Cream of tartar) Sodium hypochlorite
Calcium triple superphosphate   Sodium mono- hydrogen
    Sodium nitrate
    Sodium potassium tartrate
(Rochelle salt)
    Sodium silicate
    Sodium sulfate (glauber's salt)

* For any chemical containing sodium, the corresponding potassium or ammonium (salt) compound may be substituted.


Hazardous Waste Disposal Policy and Procedures


Please direct all questions regarding hazardous waste to