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Proper labeling of waste

All bottles of chemical waste held in the laboratory must have a Hazardous waste Container Label with the names of chemicals added to the bottle or attach a separate sheet with the chemicals added.   The date of acculumulation must also be written on the container.

The label must also indicate if the contents are non -halogenated solvents, halogenated solvents, acids, bases, flammable, reactive, oxidizer, corrosive, or toxic.

Waste labels can be obtained from EHS.

Proper segregation of waste

Do not mix incompatible chemicals in the same waste container.  For example, nitric acid and ethanol can form an explosive mixture.

Examples of incompatible mixtures.

Mixing of incompatible materials (chemicals or wastes) can result in excessive heat, over pressurization, fire or other dangerous situations. If you plan to mix chemicals or wastes in a waste container or group them in a bag, tray or bucket, you must first determine whether any dangerous situations may result.

Below are some notable situations which have occurred when incompatible materials are mixed:

• Acids and bases (ex: hydrochloric acid and ammonium hydroxide) generally results in generation of excessive heat, including boiling over. If the mixture boils over, it may result in serious injury.

• Acids and bleach, azides, cyanides, sulfides, metals, or carbides can result in the generation of toxic fumes. (Acid + Cyanide = HCN (gas)).

• Nitric or perchloric acid (even when dilute) and any organic material such as ethanol, acetic acid, or oil can result in excessive heat or a fire.

• Perchloric acid can react with wood or paper to form cellulose perchlorate which can spontaneously combust.

• Acetic acid, Acetic Anhydride, and Formic Acid are a special class of chemicals as they are both an acid and organic. In concentrated form, these materials are flammable. They should not be stored or mixed with any mineral acids.

• Peroxides and organics or metals, such as; hydrogen peroxide and ethanol, aluminum, or copper can result in a fire.

• Inorganic nitrate salts or bases and organics can form highly unstable compounds which may detonate.

• Mixing silver nitrate and ammonia with sodium or potassium hydroxide can form explosive “fulminating silver”.

• Mixing silver nitrate and ethanol has resulted in serious fires.

• Ammonium nitrate or hydroxylamine nitrate and organic material can result in an explosive compound.

• Potassium permanganate and sulfur has resulted in flash fires.

• Sodium or potassium chlorate and organics has resulted in explosions.

• Nitrobenzene and aluminum or tin chloride and organics may result in an explosion.

• Nitromethane waste must be handled separately.

• Never mix nitromethane with bases or amines,

• Or with metals or metal compounds.

• Piranha solution and any organic material or metals can react violently and result in a fire or overpressurization. Piranha solutions in contact with paper products have resulted in trash can fires. Always accumulate Piranha waste in a plastic coated glass bottle with vented cap, and wait until cool before closing. Piranha waste should be handled separate from all other waste streams.

• Azides and metals can combine to generate shock sensitive salts which can detonate.

• Activated Platinum group metals on carbon and metal hydrides have caused several lab fires.

• Chloroform and acetone with a base may react violently.

• Monomers can self-react and violently generate pressure or fire. Examples are methyl methacrylate, acrylic acid and acrolein.

• They are sold with an inhibitor to prevent this reaction. Inhibitors must be monitored to maintain their activity.

• Monomers and iron, acids or even water can result in violent reactions.

• Acetic Anhydride and water, glycols or alcohols will result in a violent reaction and possibly a fire.

Proper Storage and Segregation

All hazardous wastes must be stored in suitable containers in good condition, that are compatible with the chemical contents of the waste. The waste container must be sealed at all times unless waste is being added or removed. A secondary container should be used to contain the material in case the primary container is overfilled or fails. Leave ample head space in all liquid waste containers to allow for expansion.

All waste streams should be segregated and properly stored to ensure that chemical reactions will not occur if containers were to fail. Information to assist you in segregation can be found on material safety data sheets and/or chemical references. There may be limitations imposed by the chemical profile for the waste stream, or the treatment technology used to process the waste.

• Always keep waste bottles capped and never leave a funnel in a waste bottle.

• Maintain your waste in a secure area.

• If a container is full, take it to the appropriate waste storage area.

When taking your waste to the waste storage room, make sure that:

• All waste containers have a proper hazardous waste label with start date

• All contents are listed.

• The bottle or jar has  a cap that fits tightly or a vented cap if applicable.

• If liquid, there is at least 1 inch of head room at the top of the container.

• The outside of the bottle is clean and ry.

• Incompatible wastes are not mixed.

• Halogenated wastes are separate from non-halogenated wastes whenever possible.

• The pH is known and listed on the disposal tag.

• Follow departmental procedures for notification and delivery of waste containers.

• Departments that do not have provisions for waste storage are to contact Dennis Baden, 1950 to arrange for pick up of waste containers.