Essential Methods for Sampling Hazardous Waste

Sampling hazardous waste is key to keeping work environments safe. Hazardous waste is heavily regulated by the EPA and state representatives of EPA  such as Cal OSHA. OSHA and Cal OSHA are also relevant since they regulate protection for workers who have to handle hazardous waste that puts their occupational safety at risk. 

As a result, businesses should pay strict attention to making sure that the levels of hazardous waste on their work sites, storage facilities, and disposal grounds are at safe levels.

All hazardous substances have maximum levels that they should not exceed. Hazardous waste sampling methods ensure that you have accurate readings of hazardous waste levels in working environments. This makes it easier to protect your workers from exposure to chemical hazards and to protect the environment from hazardous waste leakage.

Understanding Hazardous Waste

Hazardous waste is defined as waste that has the potential to harm humans or pollute the environment. Hazardous wastes are defined as “solid” wastes. However, the name “solid” is technical, and hazardous wastes include liquids, solids, contained gases, and so on. 

Federal regulations regarding hazardous waste fall under the Resource Conservation and Recovery Act (RCRA) of 1976. RCRA provides a complicated definition of what a solid waste is. It also provides a detailed categorization of these wastes.

A hazardous waste is waste with one of the following characteristics:

1. Ignitability. They can catch fire or combust under specific conditions or they have flash points lower than 60°C (140°F). Used solvents are an example. 
2. Corrosivity. These are strong acids and bases. 
3. Reactivity. These are wastes that are unstable under normal conditions. They can explode or release toxic fumes when heated. For example, lithium-sulfur batteries. 
4. Toxicity. These are wastes that are fatal when ingested or absorbed by humans. Examples are mercury and lead. 

Hazardous wastes are classified by RCRA into four categories or lists: 1. F List 2. K List 3. P List and 4. U list. The table below gives the definition and examples of each.

Table 1. Lists of hazardous substances

In addition to these “listed wastes,” there are “characteristic wastes.” These are hazardous wastes that are not on the RCRA waste lists but still pose risks to people or the environment. Hazardous wastes and their levels can only be reliably detected through highly technical and scientific methods. There are various sampling methods designed just for that purpose. In the following, we take a quick look at each.

Essential Methods for Sampling Hazardous Waste

Before selecting methods to sample hazardous waste, OSHA recommends that you carry out a survey protocol. How elaborate the survey protocol is depends on several factors such as the purpose of the survey and the establishment that it has to be submitted to. 

Here is an OSHA guideline on what a survey protocol should include: 

Table 2. Criteria for survey protocol

There are several sampling methods you could employ when sampling. It depends on the chemical that you are sampling for.  Here is a brief description of each: 

1. Direct Reading. This allows you to collect large amounts of data and to clearly outline the workers’ exposure profile. You can also access qualitative data through direct observation and speaking directly to workers. However, they may lack specificity in terms of detection limit and precision.

2. Grab Sampling. This involves collecting a single, discrete sample of air, water, soil, or another environmental medium at a specific point in time and location. This method captures a snapshot of the chemical concentrations at the moment of sampling, making it ideal for short-term or incident-specific measurements. It is often used for regulatory compliance and environmental monitoring.

   However, grab sampling may not accurately reflect fluctuations over time, limiting its ability to capture longer-term exposures or variations in concentration levels.

3. Passive Sampling Methods. Passive sampling methods rely on the natural diffusion of chemicals into a collection medium, without active pumping or sampling. These devices are typically left in place for extended periods, allowing for the time-integrated measurement of contaminants in air, water, or soil.

   They are often used for monitoring low-level pollutants in the environment or workplace, as they can provide more representative exposure data over longer periods. Examples include passive badges for air monitoring and diffusion-based samplers for water quality assessments.

4. Surface Contamination Sampling Methods. Surface contamination sampling involves collecting samples from surfaces (such as floors, walls, or equipment) to assess the presence of hazardous chemicals, biological agents, or other contaminants. Methods include:

• Wipe sampling
• Vacuum collection, or 
• Tape lifts,

This type of sampling is crucial in industrial hygiene, forensic analysis, and contamination control to evaluate potential human exposure, ensure cleanliness, or assess decontamination efficacy. Surface sampling helps identify both immediate and residual contamination risks.

Factors that determine the sampling method and volume include: 

• The physical state of the waste (liquid, solid, sludge)
•  The waste container (drum, tank, pile)
• Accessibility
• Waste variability
•  Safety concerns. 

In terms of the sample volume, for solids, 500 grams in a glass container is recommended. For liquid samples, volumes fall within the range of 1–8 liters approximately. It depends on analysis parameters and solid content.

Use the appropriate device for sampling. For liquids contained in pits, drums, or tanks, weighted bottles or composite liquid waste samplers are recommended.  Augers, triers, and shovels are more appropriate for sampling solid wastes that are found in containers or piles.

What are the Safety Concerns Related to Sampling?

Hazardous waste sampling should always be performed following a detailed, facility-specific health and safety plan. Personnel must have the required OSHA HAZWOPER training and may need to participate in a medical monitoring program.

Here is a list of safety concerns to take into account when sampling: 

• PPE. The minimum personal protective equipment (PPE) for waste sampling includes:
  – Coated Tyvek coveralls
  – Gloves
  – Hard hat
  – Rubber boots
  – Splash protection
  – Face shield
  – Air-purifying respirator. Air monitoring for oxygen levels, organic vapors, and explosive atmospheres is mandatory during sampling.
  – Acid-resistant clothing for corrosive products.
  
• Considering storage conditions. Care should be taken when handling hazardous waste in challenging conditions such as bad weather or confined spaces. Metal containers must be electrically grounded to prevent sparking, and nonferrous tools should be used. Only trained personnel should open bulging or corroding drums.
• Professional conduct. Sampling personnel should work in teams, possess first aid training, and have emergency contact information readily available. Directions to the nearest hospital should be posted in case of injury.
  

Conclusion 

Hazardous waste sampling includes highly technical and scientific methods. It is a significant step or component in ensuring that you are EHS-compliant according to EPA standards. Strict protocols and testing methods should be followed when collecting samples and testing them.

We recommend relying on expert advice and help concerning sampling hazardous waste. At CDMS, we have years of expertise and experience in handling and sampling hazardous waste. We first survey the site within which you handle or store any hazardous chemical to determine the type of sampling method that is necessary. 

Then we proceed to use the most appropriate and up-to-date method according to EPA guidelines. Get in touch with one of our experts today to see how we can help with our EHS Waste Determination Services.