The New Fog and Haze Standard Is Here: 5 Things Technical Directors Must Do Now
Picture this: You’re two days into tech week when the fire marshal walks in during a haze-heavy scene. The alarm system trips. Production stops. The AHJ, most likely the fire marshal, asks to see your atmospheric effects documentation.
You have thirty seconds to produce it.
This scenario theoretically could play out in theaters across the country every week. Realistically, it only plays out with Fire Marshals (AHJ) who are really on top of it; but with awareness comes change. As of December 2023, there’s a new standard that defines what “proper documentation” actually means.
ANSI E1.23-2023, the updated standard for atmospheric effects, establishes requirements that technical directors, designers, and operators need to implement now. This isn’t theoretical safety guidance. It’s the framework that fire marshals, insurance companies, and attorneys will use to evaluate whether you did enough.
Why This Standard Matters to You
E1.23 is a voluntary consensus standard. Nobody forces you to follow it.
But here’s the reality: when something goes wrong with theatrical fog or haze, this is the document that defines whether you met the standard of care. Venues, employers, and authorities having jurisdiction increasingly treat E1.23 as the baseline for acceptable atmospheric effects practice.
The standard addresses three categories of hazards:
- Inhalation exposure to glycol-based fog, mineral oil haze, or cryogenic gases
- Slip hazards from fluid accumulation on stage floors
- Obscuration that hides egress paths or triggers fire alarm systems
Prior to E1.23’s development, ANSI E1.5 established exposure limits for glycol-based fog but provided limited guidance on control measures or operational procedures. Individual venues improvised solutions. The result was inconsistent practices and preventable incidents.
E1.23 fills that gap.
The Two Critical Roles You Must Designate
The standard creates two distinct responsibilities that someone must perform, regardless of your venue size.
The Effect Designer must be a Qualified Person with recognized credentials or demonstrated expertise to solve atmospheric effects problems. This person designs the effect, selects equipment and fluids, specifies usage procedures, and implements all standard requirements.
The Effect Operator must be a Competent Person trained in atmospheric effects setup and operation who can identify hazards and take corrective action. This person executes the designer’s plan, maintains equipment, monitors performance, and documents deviations.
One person can fill both roles if qualified. But you cannot skip these functions.
A technical director who hands a student worker a hazer without designating someone to perform Designer and Operator functions violates the standard’s framework. When problems occur, the standard establishes clear accountability for who made what decisions and who was responsible for operational controls.
The Five Things You Must Do Before Your Next Fog Cue
1. Conduct a Written Risk Assessment
The Effect Designer must determine who is exposed, for how long, and what risks they face.
Don’t limit your thinking to performers. Air handling systems recirculate fog from stages into scene shops, costume shops, dressing rooms, and offices. If you ignore those spaces during planning, you create predictable conflicts when office workers complain about air quality.
Consider exposure time differently for different workers. A lighting designer programming cues in haze for twelve hours experiences vastly different exposure than a performer rehearsing for two hours in the same space.
The standard expects exposure limits applied as time-weighted averages. Extended daily or weekly exposure requires more conservative limits.
2. Verify Your Equipment Meets Approval Requirements
Equipment must meet regulatory safety requirements in your jurisdiction. In the United States, OSHA generally expects electrical equipment used by employees to be “approved,” typically meaning listed by a nationally recognized testing laboratory.
Commercially manufactured equipment must be:
- Used according to manufacturer’s instructions
- Operated only with specified fluids and gases
- Unmodified unless the manufacturer approves the modification
Equipment modifications not approved by the manufacturer convert it to custom equipment. Whoever makes the modification becomes the manufacturer responsible for written safety assurance and operating instructions meeting ANSI E1.14 requirements.
That DIY fog machine built from heating elements and plumbing fittings? It doesn’t comply without proper documentation, regardless of how well it produces fog.
3. Establish Your Exposure Monitoring Method
The designer must determine permissible exposure by consulting ANSI E1.5 and 29 CFR 1910.1000 for United States jurisdiction. Then select one of four permitted monitoring methods:
- Calculation method: For evenly distributed haze where no person is in the visible plume
- Time/distance tables: Developed by a Certified Industrial Hygienist for specific fluid and machine combinations
- Aerosol meters: Providing real-time peak and time-weighted average readings
- Sampling pumps: With laboratory analysis for time-weighted average exposure
Each method has cost and complexity trade-offs. Aerosol meters cost thousands of dollars but provide real-time data. Time/distance tables require upfront industrial hygienist consultation but simplify ongoing monitoring. Calculation methods work for steady-state haze but not for concentrated fog effects.
Choose the method that fits your effect, your budget, and your technical capabilities. But you must choose one.
4. Write Your Fire Detection Coordination Plan
The designer must determine if smoke detection may be inappropriately triggered by the atmospheric effect. The standard permits three approaches:
Temporary interruption: With Authority Having Jurisdiction approval, venue owner approval, and approved fire watch present continuously while detection is deactivated.
Operate below trigger threshold: Design the effect to operate with fog amounts below smoke detection activation levels.
Permanent installation design: For permanently installed effects, design fire detection systems to work without false alarms.
Testing requires coordination with whoever controls the alarm system. Air handling equipment may move fog from safe locations to areas where it triggers detectors. Test with HVAC in performance conditions. Wait at least 20 minutes after testing for delayed detector response.
5. Create Your Documentation Package
The written plan must include:
- Event or production identification
- Effect Designer name
- Effect Operator names
- Safety data sheets for materials used
- Narrative description of effects with identified risks and control measures
- Contact information for problem reporting
Keep this current. Make it available on request to the Authority Having Jurisdiction.
This documentation serves two purposes. First, it proves you performed the required analysis and planning. Second, it gives operators the information they need to execute the effect safely.
What About Ventilation?
Mechanical ventilation and local exhaust reduce fog and smoke exposure and should be considered every time fog is planned.
ASHRAE 62.1-2022 provides minimal ventilation rates for stages and studios, but these maintain general indoor air quality and aren’t designed to evacuate purposefully introduced fog. Effective fog removal may require localized ventilation or high-volume extraction fans.
Calculate clearance time by determining volumetric flowrate capacities and room volume to establish necessary air changes.
Recirculating HEPA units reduce glycerin, glycol, and mineral oil-based aerosols but cannot be used for cryogenic gases, which require exhaust to outside. HEPA units don’t supply fresh air, so occupied spaces accumulate carbon dioxide from exhalation that filtration doesn’t remove.
When Effects Change, You Must Reevaluate
The Effect Designer must plan for periodic reevaluation to ensure the effect remains visually effective and doesn’t create health hazards.
Events triggering immediate reevaluation include:
- Fog or haze visible in new locations where it hadn’t been before
- Smoke detectors triggering that had not triggered before
- Aerosol meters giving changed readings from baseline
- Addition of new fog or haze effects to existing scenes
- Major renovations or ventilation system changes
Establish a reporting mechanism for exposed population members to report concerns. Don’t wait for complaints to escalate.
The Implementation Challenge
Here’s the practical problem: E1.23 requires written documentation where verbal agreements previously sufficed. It requires qualified designers where general theatrical knowledge previously seemed adequate. It requires exposure monitoring where visual assessment previously determined safety.
Small operations may lack personnel who clearly meet the Qualified Person definition. A recent graduate from a theater technology program may or may not possess “extensive knowledge, training, and experience” sufficient for Qualified Person status depending on program rigor and individual aptitude.
If you’re uncertain whether someone is qualified, seek assistance from industrial hygienists, safety consultants with entertainment industry experience, or designers with documented atmospheric effects expertise.
Exposure monitoring creates cost barriers. Aerosol meters cost thousands of dollars. Calibration factors vary by fog fluid and meter combination. Time/distance table development requires industrial hygienist consultation.
The Equipment-Based Guidelines for the Use of Theatrical Smoke and Haze, prepared for Equity-League Pension and Health Trust Funds, provides pre-developed tables as an alternative to new monitoring for each show. But those tables are based on original meter testing and may not fit every situation. The guidelines explicitly state they may not be appropriate for all productions.
Your Next Steps
If you’re a technical director: Require designers to demonstrate how their plans address E1.23 requirements before approving atmospheric effects for any production.
If you’re a designer: Implement the standard’s risk assessment, equipment selection, monitoring, and documentation requirements now. Don’t wait for someone to require it.
If you’re an operator: Understand the monitoring and control procedures the standard requires. Document deviations. Report repeated modifications to the Effect Designer.
If you’re a safety officer: Verify that plans address all applicable standard provisions before effects go into operation.
The standard’s effectiveness depends on competent execution by qualified professionals who understand both the technical requirements and the underlying safety principles.
Atmospheric effects enhance productions when properly designed, installed, operated, and maintained. E1.23 provides the framework for achieving that outcome while protecting everyone in the venue.
One More Thing
ESTA provides protocols for meter-based exposure control and calibration factors at tsp.esta.org. The Equipment-Based Guidelines are available on the Actors’ Equity website at actorsequity.org/resources/Producers/safe-and-sanitary/smoke-and-haze/.
Start there. Get the documentation. Understand the requirements. Then build your atmospheric effects program on that foundation.
Your future self, standing in front of that fire marshal (AHJ) during tech week, will thank you.
What’s your biggest challenge implementing atmospheric effects safety requirements?
Leave a comment below.
References
Entertainment Services and Technology Association. (2023). ANSI E1.23-2023: Entertainment Technology—Design, Execution, and Maintenance of Atmospheric Effects. ESTA.
Entertainment Services and Technology Association. (Current edition). ANSI E1.5: Entertainment Technology—Theatrical Fog Made With Aqueous Solutions Of Di- And Trihydric Alcohols. ESTA.
Occupational Safety and Health Administration. (n.d.). 29 CFR 1910.146: Permit-required confined spaces. U.S. Department of Labor.
Occupational Safety and Health Administration. (n.d.). 29 CFR 1910.1000: Air contaminants. U.S. Department of Labor.