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Thursday, September 11, 2008

Theatrical Smoke

Hmmmm. I wondered a bit about this:
A. Background

In 1997-99, at the request of Actors’ Equity Association (AEA) and the League of American Theaters and Producers (LATP) and with the support of the Equity-League Pension and Health Trust Funds, investigators from the Mount Sinai School of Medicine (Mt. Sinai) and ENVIRON International Corporation (ENVIRON) conducted a study to determine whether the use of smoke, haze, and pyrotechnics special effects in theatrical musical productions is associated with a negative health impact in Actors. This effort was initiated in response to ongoing concerns by Actors that the use of these theatrical effects may have an impact on their health. The results of this study were presented in the report Health Effects Evaluation of Theatrical Smoke, Haze, and Pyrotechnics (Mt. Sinai and ENVIRON 2000).

The results of the Mt. Sinai/ENVIRON study indicate that there are certain health effects associated with Actors exposed to elevated or peak levels of glycol smoke and mineral oil. However, as long as peak exposures are avoided, Actors’ health, vocal abilities, and careers should not be harmed. Pyrotechnics as used on Broadway at the time of the study did not have an observable effect on Actors’ health.

Mt. Sinai and ENVIRON recommended the following guidance levels with respect to
glycols and mineral oil:

• The use of glycols should be such that an Actor’s exposure does not exceed 40
milligrams per cubic meter (mg/m3).
• Mineral oil should be used in a manner such that an Actor’s exposure does not exceed a peak concentration of 25 mg/m3.
• For chronic exposures to mineral oil, the existing standards established for oil mists (5 mg/m3 as an eight-hour time-weighted average) should also be protective for
Actors in theatrical productions.

.....

II. SAMPLING METHODOLOGY

A. Selection of Chemicals to be Sampled

The chemicals used to produce theatrical effects included in this Protocol are (1) glycols for smoke generation, and (2) mineral oil used for a haze effect.

1. Glycols
Mixtures of various glycols are used to generate smoke effects. Glycol aerosols are generated by heating a glycol/water solution and feeding the vapor through a critical flow orifice. The glycol solutions currently used to generate smoke effects consist of mixtures of 1,3-butylene glycol (BG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), triethylene glycol (TEG), and water. Upon entering the atmosphere, the vapor condenses rapidly to form fine droplets, producing a visible aerosol. The particles subsequently revolatilize into the vapor phase and dissipate.

2. Mineral Oil
A haze-like effect can be produced by generating an aerosol of mineral oil. Oil mist effects are generated by “cracking” a USDA approved food or pharmaceutical grade mineral oil through a dispersion system using high-pressure air. Haze machines (“hazers”) typically produce a fairly uniform particle size distribution with aerodynamic diameters ranging from 0.1 to 1.0 micrometers (μm). The haze particles will dissipate via room ventilation.

While other chemicals may be available currently or in the future for generating smoke and haze effects (e.g., glycerol), these chemicals were not included in the Mt. Sinai/ENVIRON study. Thus, the conclusions and guidance levels developed from the Mt. Sinai/ENVIRON study will not necessarily be applicable to these alternative chemicals.

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