CASE STUDY | Aerosol Analysis: Was There a Formulation Change?

Concern: Tile Sealant No Longer Safe?

A popular aerosol tile sealant had been a best seller for years. Consumers loved it – it worked well and had a good safety record. The manufacturer was puzzled when their product started being linked to illnesses – and even deaths. Facing litigation, they turned to MAS scientists to learn why a long-time safe product had become a potential health hazard.

MAS Solution: Make It Real

The most obvious answer was that a formulation change had been made to one of the components in the sealant, without the manufacturer’s knowledge. For MAS scientists to confirm this hypothesis and define exactly what had been changed, they needed to determine exposure during typical product use by analyzing both the air and surfaces. To simulate real world conditions, they constructed a shower stall inside MAS’s environmental characterization lab (ECL). The ECL allows containment of hazardous pollutants through a combination of negative pressurization and HEPA air filtration. Wearing proper protective gear, an MAS employee entered the chamber and sprayed the sealant – simulating actual consumer use of the product.

Test Process: Analyze the Collected Data

The employee wore an air sampling collection device, and there were several others in the ECL. MAS scientists gathered area and personal air samples, along with surface deposit samples, to determine the presence of volatile organic compounds (VOCs) and fluoropolymers during typical use. These products were analyzed by GC/MS to establish a component list. Air sample analysis by NIOSH method 1450/1500 consisted of desorption of the charcoal by carbon disulfide, followed by identification and quantification of aromatic hydrocarbons by GC/FID. For this test the cans were inverted and the product sprayed directly into a collection vial, then analyzed by GC/MS. Additionally, an analysis was performed to measure the residual dried components. A profile of each formulation was prepared, along with semi-quantitative results of each identified compound in the profile.

Results: Identifying the Unauthorized Formulation Change

MAS’s analysis confirmed that an unauthorized formulation change had been made by one of the manufacturer’s suppliers. But which component?

Earlier formulations of the sealant contained n-butyl acetate – a solvent with a pungent/acrid odor. Because of the overwhelming smell of the older formula, consumers would instinctively leave the area and limit their exposure.

In the new formula, the supplier substituted a sweet smelling, multi-component solvent. This seemingly inconsequential change turned out to be the root of the problem, as consumers would linger too long in the sprayed area and be overexposed to the fluoropolymer solvent. Based on MAS’s tests, the manufacturer was able to return to the safer, albeit less pleasant smelling, formulation.

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