Laboratory Waste is called "Unwanted Material" at the University of Houston. This seemingly minor change in language carries great regulatory significance. Unwanted material is any waste generated in a laboratory that is not radioactive waste or biomedical waste. 

Laboratories

Laboratories aren't just science labs for this purpose, they also consist of: 

• Laboratories
• Laboratory preparatory areas
• Laboratory stockrooms
• Machine shops used for teaching or used in preparation of materials and equipment for laboratory experiments
• Photography studios used for teaching
• Art studios used for teaching
• Cooking, food preparation, and food science laboratories and facilities used exclusively for teaching
• Medical schools and supporting laboratories when used for teaching

Areas that do not qualify for management under laboratory rules include: 

• Building maintenance and repair
• Automotive maintenance and repair
• Clinics and medical facilities not used for teaching
• Commercial and tenant laboratories
• Photography and art studios not used for teaching
• Food service locations not used exclusively for teaching
• Machine shops not used exclusively for teaching

Radioactive waste is excluded

Radioactive waste cannot currently be classified as unwanted materials, even if it could have characteristics of hazardous waste. It must be managed and accumulated separately from non-radioactive waste. If something meets the criteria for management as radioactive waste, it must be managed as such. 

Biomedical waste is excluded

Biological wastes pose a hazard through the transmission of disease by the disease-causing agent itself (bacteria, virus, prion, amoeba, etc.), through the risk of augmentation of the pathogenic potential of disease-causing agents (such as by the transmission of recombinant or synthetic nucleic acid molecules), or by creating conditions amenable to such consequences. These wastes are addressed through several regulations and institutional rules and may be generally addressed as “biological waste”, “biohazardous waste”, or “red bag waste”. As these types of waste are addressed under different regulations that do not require professional evaluation of a waste for classification, they cannot appropriately be managed as "unwanted materials" because their regulatory status and hazards are known. Biological waste can be identified by the following descriptors:

In vivo or ex vivo recombinant or synthetic nucleic acid molecules

Recombinant or synthetic nucleic acid molecules require special disposal practices. This requirement extends to organisms or disease-causing agents bearing these molecules. This serves to prevent release of these nucleic acids. Work with these materials requires review by the Institutional Biosafety Committee, and such work will be identified. Materials originating from such work that meet the definition of waste are biological wastes.

Microbiological waste

Microbiological waste consists of material that is discarded, abandoned, unwanted, or no longer usable for its purpose, specifically:
• Cultures and stocks of infectious agents (or agents with recombinant or synthetic nucleic acid molecules)
• Cultures of specimens from medical, pathological, pharmaceutical, research, clinical, and other laboratories
• Live and attenuated vaccines (excluding empty containers)
• Used culture dishes (excluding those that will be reused)
• Used transfer, inoculation, or mixing devices (excluding those that will be reused)

Pathological waste, blood, and other potentially infectious material

Pathological waste refers to the following materials when originating from humans, including but is not limited to:
• Body parts
• Tissues or fetuses
• Organs
• Bulk blood and body fluids (over 100 mL aggregated over all containers)
• Laboratory specimens of blood and tissue after completion of laboratory examination
• Remains of human bodies donated for the purposes of teaching or research after the completion of such activities

Blood with regard to this classification refers to the following materials in any volume from humans or where the source cannot be identified:
• Blood
• Blood components
• Products made from blood

Other potentially infectious material refers to material from humans, experimental animals, or where the source cannot be identified, and includes:
• Semen
• Vaginal secretions
• Cerebrospinal fluid
• Synovial fluid
• Pleural fluid
• Pericardial fluid
• Peritoneal fluid
• Amniotic fluid
• Saliva (in dental procedures)
• Any bodily fluid visibly contaminated with blood
• All bodily fluids in situations where it is difficult or impossible to differentiate between body fluids
• Any unfixed tissue or organ other than intact skin
• HIV-containing cell or tissue culture, organ cultures
• HIV- or HBV-containing culture media or other solutions

Animal waste

Animal waste refers to the following materials from animals that have intentionally been exposed to pathogens or disease-causing agents:
• Carcasses (not including chemically fixed carcasses that are managed as unwanted materials)
• Body parts
• Blood
• Blood components
• Products made from blood
• Bedding (including feces and urine not directly deposited into bedding)

Other healthcare-related biological waste

Materials that come into contact with bodily fluids not specifically covered in other classifications as well as the bodily fluids themselves that are removed from the point of collection and leave the possession of the person giving the sample also require regulated disposal. Some existing examples include:

• Urine sample cups that are removed from the bathroom in which they are collected for analysis in a laboratory down the hall
• Saliva swabs that are removed from the location in which the sample is taken and analyzed at the University

This would not include:

• Urine sample cups that are collected and hand-carried by the person giving the sample to a location for colorimetric results to be read prior to returning to the same bathroom to flush the sample and place the empty container in the trash
• Saliva swabs that are sent to an off-site laboratory for analysis (because they would not be waste until they are analyzed by the off-site lab)

Sharps

Sharps, when contaminated are considered biological waste and must be disposed of in sharps containers. Some unused sharps may also qualify as regulated medical waste. When possible, treat all sharps as biomedical waste. For more information see the Regulated Waste Manual.