5.2 Hazardous Waste, Medical Waste, and Amalgam Disposal
Key Takeaways
California law requires full sharps containers to be closed and not stored ready for disposal for more than 30 days without approval (Health and Safety Code § 118285).
A California generator of less than 20 pounds of biohazardous waste a month may store it above freezing for no more than 30 days (Health and Safety Code § 118280(e)).
EPA's dental amalgam rule required existing dental dischargers to install amalgam separators meeting a 95% removal standard by July 14, 2020 (40 CFR § 441.30).
Under 40 CFR § 441.30, a broken amalgam separator must be repaired or replaced within 10 business days.
EPA's dental amalgam rule bans chairside trap amalgam from drains and line cleaners with a pH below 6 or above 8 (40 CFR § 441.30(b)).
Why waste is a practice-owner task
Task T109 asks the owner to comply with OSHA standards for hazardous and biohazardous materials. Its knowledge statements cover hazardous-waste disposal (K1091), biohazardous-waste disposal (K1092), disinfection (K1093, covered in Section 5.1), and amalgam disposal (K1094). Section 1005(b)(22) points to the rest of the law: contaminated solid waste must be disposed of under "applicable local, state, and federal environmental standards."
Three waste streams
| Stream | Examples | Governing law | Where it goes |
|---|---|---|---|
| Medical (biohazardous) waste | Waste containing recognizable fluid blood, such as saturated gauze; surgical tissue suspected of infection | California Medical Waste Management Act, Health and Safety Code § 117600 and following | Red biohazard bag in a labeled rigid container, then a registered medical waste hauler or mail-back |
| Sharps waste | Needles, scalpel blades, root canal files, used glass anesthetic cartridges, broken contaminated glass, other items that can cut or pierce | Same act | FDA-cleared sharps container, then a hauler or mail-back |
| Hazardous waste | Scrap amalgam, amalgam-containing traps and filters, extracted teeth with amalgam, fixer, lead foil | Hazardous waste law (DTSC, 22 CCR) and the EPA amalgam rule | Hazardous waste recycler or hauler; never red bags, sharps containers, trash, or drains |
Ordinary items such as barriers, gloves, and masks that are not saturated with blood usually go in regular trash unless a local rule says otherwise.
Medical waste rules (K1092)
- Separate at the point of generation. Medical waste must be kept apart from other waste (§ 118275(a)(1)).
- Biohazard bags must be labeled and tied closed. For storage or transport they go in a rigid, leak-resistant container with a tight lid, labeled "Biohazardous Waste" or with the biohazard symbol and the word "BIOHAZARD" on the lid and sides (§ 118280(a), (c)).
- Sharps containers must be FDA-cleared, rigid, puncture-resistant, and never lined with a plastic bag (§ 117750). When full, tape or lid them closed, label them "sharps waste" or with the biohazard symbol, and store them ready for disposal no more than 30 days without approval (§ 118285).
- Storage limits for biohazardous waste (§ 118280(e)):
| Generation rate | Maximum storage above 0°C (32°F) |
|---|---|
| 20 pounds or more per month | 7 days |
| Less than 20 pounds per month (most dental offices) | 30 days |
| Any rate, stored at or below 0°C | 90 days |
- Records: a small-quantity generator that is not required to register must keep a document explaining how it contains, stores, treats, and disposes of medical waste, plus hauler or mail-back records, for at least three years (§ 117945).
Hazardous waste and chemicals (K1091)
Dental amalgam is roughly half mercury, so scrap amalgam is managed as hazardous waste and should be recycled. The CDA's amalgam best-management practices, several of which it marks as mandatory under Title 22, say:
- Do not put amalgam, broken capsules, extracted teeth with amalgam, or amalgam-laden traps and filters in red bags, sharps containers, or the trash.
- Do not rinse traps or filters in the sink.
- Store dry scrap amalgam in a sealed container labeled "Scrap Dental Amalgam" with the office name, address, phone number, and start date, and send it to a recycler.
- Use precapsulated amalgam, never bulk mercury, and keep a generation and disposal log.
Other hazardous materials include used X-ray fixer (silver), lead foil from film packets, and some sterilant and disinfectant chemicals. Under Cal/OSHA's hazard communication standard, keep Safety Data Sheets available and train staff on each chemical.
The EPA amalgam separator rule (K1094)
40 CFR Part 441 applies to dental dischargers, meaning offices that send wastewater to a public sewage treatment plant.
Exempt: practices limited to oral pathology, oral and maxillofacial radiology, oral and maxillofacial surgery, orthodontics, periodontics, or prosthodontics; mobile units; and offices that do not place amalgam and remove it only in limited emergencies. The last group must still file a one-time certification.
Requirements for everyone else (§ 441.30):
- Install an amalgam separator certified to ISO 11143 or ANSI/ADA 108 at 95% removal, sized for the maximum flow. Existing sources had to comply by July 14, 2020.
- Inspect it following the manufacturer's manual and replace the collection unit when full or on schedule.
- Repair or replace a malfunctioning separator within 10 business days.
- Follow two best management practices: never flush waste amalgam from traps, screens, filters, or cuspidors to the sewer, and never clean lines with oxidizing or acidic cleaners (such as bleach, chlorine, iodine, or peroxide) that have a pH below 6 or above 8.
Paperwork (§ 441.50): submit a One-Time Compliance Report to the local control authority. Existing offices had to do this by October 12, 2020. New offices must do it within 90 days of first discharge, and a new owner must file within 90 days of a transfer. Keep the report for as long as the office operates, and keep inspection, maintenance, and disposal records for three years.
Important
An extracted tooth with an amalgam restoration goes to the amalgam recycler, not to the medical waste container. Teeth are expressly excluded from California's definition of "pathology waste" (Health and Safety Code § 117690(b)(2)); a tooth without amalgam may be returned to the patient or handled with the office's medical waste.
Where should an extracted molar containing a large amalgam restoration be placed?
In the red biohazard bag with other surgical waste
In the sharps container because it is hard and may cut the bag
In the regular trash after disinfection
In a sealed amalgam-waste container sent to a hazardous waste or amalgam recycler
A general dentistry office that places and removes amalgam discovers that its amalgam separator stopped working. What does the EPA dental amalgam rule require?
Repair it according to the manufacturer's instructions or replace it with a compliant unit within 10 business days
Report the malfunction to the Dental Board within 7 days
Stop using the separator and rely on chairside traps until the next annual inspection
Replace it within 90 days after filing a new one-time compliance report
A small dental office generates about 8 pounds of biohazardous waste a month and stores it at room temperature. What is the longest it may keep that waste on site without approval?
7 days
30 days
90 days
One year
Sections you finish are checked off in the contents.