The use of atmospheric effects — fog, haze, smoke, and so on — in the theatre has long been a contentious issue between designers who want the effects, actors, singers, crew, and musicians who don't want to breathe it, and producers who want to keep both sides happy. For over a decade the fog issue has been a thorn in the sides of all involved.

There have been tests by manufacturers as well as opposing tests done by the Actors' Equity Association/League of American Theatres and Producers. There have been lawsuits and attempts to keep the effects out of productions. More recently, a truce has been called between the warring sides with a test and standards set for the amount of atmospheric effects that can be used in a production. The Entertainment Services and Technology Association (ESTA) has created a fog-testing program that is easy to perform, does not cost a lot to do, and provides information on the proper use of atmospheric effects in productions.

ESTA's new theatrical fog testing program asks theatres to take a proactive role in the ongoing fog conversation and demonstrate that they are using theatrical fog responsibly. Because there are clear standards and guidelines that detail the responsible use of fog — including guidelines endorsed by Actors' Equity — theatres that demonstrate that they are using fog according to these accepted standards should alleviate performers' and crew members' concerns.

The program, titled “A Test Is Worth a Thousand Words,” gives theatres the information and support they need to monitor and test all types of fog, including glycol/glycerin, mineral oil, dry ice/liquid CO2, and liquid nitrogen fogs; compare results to accepted standards and guidelines; tell performers and crew members that the theatre monitors and tests its fog; and give them the test results for their productions.

“Theatres are in a difficult position because audiences want special effects, but performers and crew sometimes express concerns about theatrical fog,” explains Lori Rubinstein, ESTA executive director. “There are a number of industry standards and guidelines — including OSHA standards and guidelines from the Actors' Equity Association/League of American Theatres and Producers study — that set limits on the amount of smoke and fog that can be used on stages. We expect that if theatres demonstrate that they are using fog according to these standards and guidelines for each individual production, it will address any remaining concerns about these effects.”

Exposure limits and usage guidelines set forth in the Actors' Equity/League study now are written into all Equity contracts for Broadway and First Class Touring productions. In releasing the study's results, Equity said, “It is expected that the new exposure limits and usage guidelines will become the universal standard for the use of theatrical smoke on all stages presenting live theatre in the United States and internationally.”

“Now that there are acceptable limits, and we can test to them and say that we meet them, this can be very reassuring,” says Eddie Kramer, electrician, Radio City Music Hall.

“It makes sense to test for any chemical products our employees are exposed to,” adds Tom Briggs, director of safety, Madison Square Garden. “From what I've seen, Local 1 stagehands are very familiar with the Actors' Equity guidelines. In fact, they gave them to me.”

Theatres participating in the “A Test Is Worth a Thousand Words” program will receive a brochure that includes all the information theatres need to monitor and test their fog use, access to the necessary equipment, a 17"x24" poster directed to performers that can hang backstage, and a flyer that can be distributed to performers with scripts, rehearsal schedules, or in response to specific questions.

The program recommends testing at the beginning of each production using the exact conditions — equipment, amount of fog used, length of the fog cue, performers' and crew members' positions relative to the fog equipment, air circulation, room temperature — that will be used during performances. Theatres then should monitor fog use to ensure that performance conditions replicate testing conditions. If conditions are consistent, there should not be a need to repeat the test during the production run. Thus, testing can be a one-time cost when a new production loads in, not an additional cost for each performance.

Of course, if testing shows that the fog use does not fall within accepted standards, the theatre should decrease the amount of fog, move performers or crew farther from the fog, or make other appropriate changes. Then the theatre should test again until the fog use falls within accepted limits.

Participating in the program has minimal cost to theatres. There is no charge to join the program and receive printed materials. Monitoring and testing can be done in-house, by the theatres' employees, with no additional training. The cost of renting equipment for testing is only $50-$200, depending on the type of fog used.

Theatres or theatrical organizations interested in participating in the program or learning more about it should contact Lori Rubinstein or Karl G. Ruling at ESTA by phone at 212-244-1505, or via e-mail at

“A Test Is Worth a Thousand Words” is sponsored by the Entertainment Services and Technology Association (ESTA). The following industry publications and associations are contributing to the cost of printing materials for this program: Entertainment Design, Lighting Dimensions, and Stage Directions magazines, and the United States Institute for Theatre Technology (USITT).