Summary:

Tear gas is a riot control agent (RCA), such as CS, CN, OC or pepper spray used by police and tactical teams. Tear gas imploded in buildings are chemical irritants to control or disperse people, or to force compliance. Not all tear gas is the same, where concentrations of chemicals in domestic law enforcement vs. riot control tear gas, vs. military tear gas can vary substantially. The delivery of tear gas projectiles includes hand-thrown canisters/grenades, launchers sending in 37mm and 40mm munitions, 12-gauge shotgun rounds and launching cups, to aerosol and thermal fogger gas dispersal units. Some tear gas munitions produce pyrotechnic smoke and oxidizing residue where heat energy may burn materials around where they land.

When tear gas implodes indoors, it usually involves a higher-risk law enforcement operation, such as:

• During the execution of a search and arrest warrants against violent offenders or drug operations.
• Individuals that barricade themselves inside a building for one reason or another.
• Narcotics raids (meth, fentanyl or trafficking operations), where officers expect armed resistance.
• Individuals are in crisis (e.g., armed with weapons, threatening suicide or are violent) where they refuse to leave the building.
• Violent offenders holding others as hostage, where tear gas is used to disorient and temporarily incapacitate hostage-takers, allowing officers to extract individuals and take control of the situation. 

Not knowing the cause of the tear gas implosion and the amount of damage caused by tear gas: 

• Remediators and environmental professionals are often left blind in not knowing the hazards they can be exposed to, which requires the inspection and assessment process to be completed wearing appropriate personal protective equipment.  

Responsibility:

• Once tear gas is imploded indoors, it often results in significant contamination affecting HVAC systems, drywall, flooring, furniture, cabinetry and personal property. 
• The remediator is responsible for ensuring they have a valid written contract covering worker protection and outlining the methods and procedures for assessing and decontaminating tear gas. 
• Once remediation work is completed, the remediator is expected to document and provide post-remediation verification (PRV) tests confirming their work was completed successfully.  

Contracts:

Completing a tear gas cleanup project creates unusual liability exposures to the remediator, such as chemical and biological, cross-contamination of unaffected areas or buildings, incomplete decontamination risks impacting the building and other buildings, contaminating the remediators’ equipment and health risks affecting workers and occupants. To protect both the remediator and the property owner, the “tear gas remediation contract” should be unique, such as:

• Get a release from the customer stating the building, contents and the environment have been released by crime-scene investigators. (When possible, identify the law enforcement agency, name and phone number of the investigator, case number and release date.) 
• When customer contents are present, the responsibility in handling, decontaminating, boxing, disposing and storing tenant contents is the cost of completing work under the contract. 
• When tenant contents are present, the responsibility in handling, decontaminating, boxing, disposing and storing tenant contents is the cost of completing work under the contract. (Because many tear gas projects cannot be decontaminated successfully when tenant contents remain.) 
• The contract allows the remediator to:
• Take photos and 3-D documentation. 
• Secure the property from public view.
• Create safety procedures that are established by safety professionals and industrial hygienists.
• Complete environmental tests (toxic chemicals, tear gas, smoke from a fire, asbestos, lead).
• Establish independent protocols for working in unsafe and hazardous environments.
• Identify total loss items from salvageable and restorable items, where total loss items are disposed. 
• Identify limitations in completing certain types of work without change orders.
• Provide independent post-remediation verification (PRV) clearance tests.  

Qualifications:

The remediator (employer) completing tear gas cleanup shall comply with all state and federal OSHA regulations and provide employees with appropriate jobsite training and safety and health monitoring, such as:

• 29 CFR 1910.141 Sanitation.
• 29 CFR 1910.1000 Air Contaminants.
• 29 CFR 1910.134 Respiratory Protection.
• 29 CFR 1910.1030 Bloodborne Pathogens.
• 29 CFR 1910.133 Eye and Face Protection. 
• 29 CFR 1910.132 General Requirements for PPE.
• 29 CFR 1910.145 Accidental Prevention Signs and Tags.
• 29 CFR 1910.1200 Hazard Communication Standard (HazCom Standard).
• 29 CFR 1910.120 Hazard Waste Operations and Emergency Response (HAZWOPER).
• OSHA General Duty Clause which is a regulation under 29 U.S.C. 654, (Section 5(a)(1). 

State requirements, such as:  

• Heat Illness Prevention Program.
• Injury and Illness Prevention Program (IIPP).
• Chemical exposures, such as California OEHHA guidelines.
• Containment and disposal of regulated substances, such as asbestos and lead-based paint.
• EPA/DEA – Hazardous waste handing, removal and substance disposal.  

• Education note:
  • Inside each of the above regulations are elements that may apply when workers are known or anticipated to be exposed to tear gas compounds, toxic and hazardous substances, explosive and reactive environments, along with establishing procedures for decontamination and providing medical surveillance (e.g., exposure to environments having toxic substances or drug compounds).

Job Hazard Analysis:

A job hazard analysis (JHA) (also known as a job safety analysis, JSA) is required when inspecting a tear gas impacted building. The JHA is a systematic-structured process where safety professionals, industrial hygienists and other qualified persons identify, evaluate and control hazards that remediators may experience during entry, inspection and decontamination. 

Not knowing what hazards are present, OSHA requires a JHA is required on all tear gas projects to identify chemical, physical, biological and ergonomic safety hazards such as:

• Slip, trip and fall.
• Bloodborne pathogens.
• Shrapnel or shards of glass.
• Illegal drugs and precursors.
• Unsafe or unstable buildings.
• Skin and respiratory reactions.
• Acute and chronic health effects. 
• Toxic, explosive and reactive substances and gases.

The JHA Covers:

• Exterior Perimeter Protection:
• Protect the building as a security measure, safety precaution and a means of reducing cross-contamination involving:
• Exterior stabilization.
• Fencing.
• 24-hour security. 
• Warning signs.
• “Do Not Enter: tape.
• Secure the perimeter or hot zone from other zones. 
• Indoor Stabilization:
• Interior stabilization caused by:
• Fire.
• Explosion.
• Police entry.
• Secure one environment (building, area, room) from another, such as with:
• Board-up.
• Establishing negative air pressure.
• Bring in fresh air to dilute contaminated air.   
• Based on priority and risk, each hazard is to be contained and removed:
• Identify and secure (without touching) crime scene substances that may have been missed by investigators:
• Drugs.
• Guns.
• Money.
• Body parts.
• Identify, stabilize and remove flammable and reactive materials:
• Pyrotechnic munitions. 
• Solvents and extraction agents – acetone, toluene, ether, benzene, ethanol, acetonitrile, methanol, chloroform, dichloromethane.
• Corrosives – hydrochloric acids, sulfuric acid, sodium hydroxide, anhydrous ammonia, acetic acid and citric acid.
• Reactive and Oxidizers – red phosphorous, iodine, lithium (from batteries), sodium metal.
• Precursors – such as pseudoephedrine, ephedrine.
• Identify, contain and remove secondary hazards, such as:
• Bloodborne pathogens.
• Sharp objects, shrapnel and shards of glass.

Personal Protective Equipment (PPE) and Decontamination:

PPE is required during inspection when handling and removing contents and decontaminating buildings. The type and level of PPE depend on the JHA that established what agent, formulation, delivery device and concentrations are present. 

At a minimum, assume that respiratory protection, eye protection, chemical-resistant gloves and disposable body coveralls are required. When investigators and workers find the level of PPE is not protecting them, PPE is to be increased to PAPR or SCBA and chemically protective suits.

• Education Note:
  • “Administrative” and “Engineering Controls” are to be in place to lessen the level of PPE. 
  • The remediator is to have a written respiratory protection program which is site-specific. However, when the level of PPE is not sufficient to protect workers from exposure, PPE must be increased.
  • After completing investigations and work, tear gas and other chemical agents including bloodborne pathogens must be removed from PPE, the under clothing of workers and work boots and exposed skin and hair. To complete this, an OSHA-compliant decontamination plan must be in place. 
  • After an exposure incident occurred, a medical-surveillance program must be in place. 

Chemistry and Worker Exposure Discussion:

CS Tear Gas:

• CS tear gas has the chemical name of 2-chlorobenzalmalononitrile / o-chlorobenzylidene malonitrile. The smoke mixture of CS tear gas contains the active ingredient of CS, where among other compounds it contains potassium chlorate. Potassium chlorate converts into potassium chloride is it reacts with heat, adding to the amount of smoke produced by the grenade. In addition, magnesium carbonate keeps acidity levels in check, where nitrocellulose binds everything together. The smoke dispersion of CS grenade produces a cloud of particles into surrounding rooms. Afterwards, an accumulation of powdery residue can be seen on some surfaces, where the majority of the powdery residue from each grenade remains unseen at the microscopic level.
• Over time, CS gas oxidizes in air, where it may not be detectible to most persons’ human olfactory receptors, including irritation to eyes and skin. However, increasing temperature and relative humidity can cause adhered and bound powders to reactivate and release CS gas, resulting in workers and occupants to experience the continued effects of CS tear gas.

CN Tear Gas:

• CN tear gas has the chemical name of phenacyl chloride (α-chloroacetophenone). Depending on the munition and carrier, CN is typically formulated as a solid particle or solution where it can be dispersed as an aerosol, smoke or spray. 
• CN varies in concentration and carrier (dry powder, solvent, pyrotechnic composition) where its persistence affects cleanup of building semi porous and porous surfaces, insulation, HVAC systems, electronics and electrical. CN also affects contents whether they are hard surface, semi porous or porous. The salvageability of contents depends on the degree of exposure and porosity. 

OC Tear Gas:

• OC tear gas not a true “gas,” it is oleoresin capsicum (an oil-based extract) made from hot chili peppers whose active ingredients are capsaicinoids (chiefly capsaicin and related molecules). Synthetic OC is pelargonic acid vanillylamide (PAVA), also called nonivamide, which is often used by police and tactical teams because it is similar in effect as natural OC but easier and less expensive to manufacture. The delivery of OC is often by an aerosol spray or hydrocarbon propellant, but it can be in projectiles that produces extreme eye pain, coughing, airway irritation and skin burning.
• OC is oily, viscous, and lipid-soluble. It can persist longer on surfaces than dry powders, where HEPA vacuuming, for example, will not remove it. Because it is lipid-soluble (non-polar), it is not dissolved easily with water, where hot water detergent scrubbing is required to remove surface oils and after rinsing, a second detergent cleaning is required to release oils from pores. During cleanup, workers can experience penetration of OC oils through latex gloves, causing skin reactions and burning. OC can also penetrate non-chemically protective outer clothing, transferring oils into under clothing and on workers’ skin.

Testing for Trace Levels of CS, CN and OC Tear Gas:

CS and CN Tear Gas

• Screening:
  • UV blacklight (usually long wave 365nm) can sometimes identify certain CS and CN powdery residues including OC oily substances. When there appears to be a positive UV screening result, capture the results with a camera. While the UV light screening method may prove beneficial (showing surfaces are not contaminated or they are contaminated), it is not a substitute for using wipe samples and proper laboratory confirmation.   
  • Immediately or shortly after tear gas contamination, colorimetric gas detection tubes and wipes may provide real-time positive results in air, such as available through Draeger, Gastec and Sensidyne. Surface wipe test strips may provide for a rapid mapping of “hot spots,” especially OC smears, but they are not as sensitive as chemical wipes and laboratory confirmation. 
  • Portable handheld MS and TD-MS and portable GC-MS analyzers can provide for a rapid screening, but the results become less reliable the longer the scene becomes older. These portable units are expensive and require a considerable amount of training in use.   
  • PIDs measure total VOCs and not specifically CS, CN and OC chemicals. PIDs give a single reading (usually reported as isobutylene equivalents) that indicates “something” volatile is present, but they cannot say “what” that something is. In other words, they are poor at detecting low-vapor-pressure solids/particulates that dominate CS/CN exposures. Where PIDs may be a benefit is identifying solvents, propellants or combustion products released by pyrotechnic canisters. Do not interpret a low PID reading as “safe” for CS/CN/OC exposure, because a low PID reading can occur even with hazardous particulate residue present. If PID spikes occur, treat as an indicator to don (put on) appropriate PPE and collect confirmatory samples (wipes/ filters/sorbents) for laboratory analysis.
• Surfaces:
  • Solvent-compatible lint-free wipes (e.g., isopropanol/methanol-wetted cotton or commercial wipes), where the laboratory will solvent desorb and analyze by GC-MS/LC-MS confirmation.
  • Vacuum samples can be collected of surface dust using 37mm closed-face cassette with pre-loaded PTFE (Teflon) membrane (chemical-resistant; 0.3 to 1.0 um).   
• Air Samples:
  • Low flow battery powered area pumps with recent calibration, where the collection of air is 2.0 L/min for a 4 hour minimum sampling time. The laboratory will analyze by solvent desorption TD-GC/MS or HPLC. (check with laboratory)
  • 37 mm or appropriate cassette loaded with PTFE or glass-fiber filters for particulate CS capture.
  • Collecting SVOCs requires using sorbent tubes that are specified by the laboratory, such as Tenax TA, where the laboratory will analyze by solvent desorption TD-GC/MS or HPLC. (check with laboratory) 
• Controls:
  • Field blanks are required, including collecting control samples from unaffected areas. 

Worker Protection Phase Management:

1. Phase 1:
1. Protect workers with a proper work environment that will not cause injury or illness.
2. Install OSHA compliant administrative and engineering controls, such as installing canopies and decontamination station outside (outdoor) of work areas.
3. Recognizing PPE and the environment may cause heat stress or heat illness, a written heat-related illness monitoring program for workers may be required. https://www.dir.ca.gov/dosh/etools/08-006/EWP_training.htm 
4. Ensure workers take the proper number of breaks and fluid intake.
5. Ensure there is a portable sanitary toilet, handwashing station and cleaning supplies nearby. https://www.dir.ca.gov/title8/3457.html  
6. Ensure there is a construction first aid kit that is complete and meets ANSI/ISSA Z308.1-2021 compliance. What’s new? Go to: https://aerohealthcare.com/us/ansi-z308-1-2021/  and  https://www.cintas.com/firstaidsafety/firstaidsupplies/fas-ansi-protocol/  
7. Depending on the situation, PPE includes protective disposable suits, such as Level C or Level B.  https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.120AppB  
8. nitrile coated work glove such as https://mazerwholesale.com/shop/personal-protection-products/nitrile-work-gloves/  
9. Full face respirator with HEPA/OV or HEPA/acid gas cartridges https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134 
10. Completing decontamination https://www.osha.gov/hazardous-waste/decontamination and https://www.osha.gov/shms/chapter-26 and https://www.dir.ca.gov/title8/5192.html  
2. Phase 2:
1. Complete a job hazard analysis (JHA) https://www.osha.gov/sites/default/files/publications/osha3071.pdf and https://www.osha.gov/sites/default/files/Job_Hazard_Analysis_Worksheet.pdf and https://www.osha.gov/sites/default/files/resource_jha_guide.pdf  
2. Remove recognized hazards https://www.osha.gov/safety-management/hazard-prevention and https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.120 and https://www.osha.gov/hazcom/ghd053107  
3. Remove bloodborne pathogens https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1030 and https://www.dir.ca.gov/title8/5193.html 
3. Phase 3:
1.  Establish and use appropriate engineering controls, such as negative air pressure https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.1101AppF and https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.57