Risk assessment for consumer exposure to toluene diisocyanate (TDI) derived from polyurethane flexible foam

Abstract

Polyurethanes (PU) are polymers made from diisocyanates and polyols for a variety of consumer products. It has been suggested that PU foam may contain trace amounts of residual toluene diisocyanate (TDI) monomers and present a health risk. To address this concern, the exposure scenario and health risks posed by sleeping on a PU foam mattress were evaluated. Toxicity benchmarks for key non-cancer endpoints (i.e., irritation, sensitization, respiratory tract effects) were determined by dividing points of departure by uncertainty factors. The cancer benchmark was derived using the USEPA Benchmark Dose Software. Results of previous migration and emission data of TDI from PU foam were combined with conservative exposure factors to calculate upper-bound dermal and inhalation exposures to TDI as well as a lifetime average daily dose to TDI from dermal exposure. For each non-cancer endpoint, the toxicity benchmark was divided by the calculated exposure to determine the margin of safety (MOS), which ranged from 200 (respiratory tract) to 3×10(6) (irritation). Although available data indicate TDI is not carcinogenic, a theoretical excess cancer risk (1×10(-7)) was calculated. We conclude from this assessment that sleeping on a PU foam mattress does not pose TDI-related health risks to consumers.

From the Synthesis of Biobased Cyclic Carbonate to Polyhydroxyurethanes: A Promising Route towards Renewable Non‐Isocyanate Polyurethanes

“…The emerging recentt rend is the elaboration of non-isocyanate polyurethanes (NIPUs) because isocyanates are harmful and suspected to be carcinogenic. [14] Repeated exposure can lead to skin irritation and incurable respiratory problems, such as long-term asthma. Moreover,t he synthesis of isocyanates requires the use of noxiouss ubstances,s uch as phosgene.…”

“…[1] The current challengei st os ubstitutef ossil resourcesb yr enewable ones to synthesize new promising molecules or building blocks for the elaboration of sustainable materials, especially new biobased polymers. [2] Biobased polymers are defined as either partly (> 20 %) or fully based on biomass (e.g.,from vegetable derivatives, animals, and microorganisms).B iobased contentsa re mainly determined throught he 14 Cc ontentb ecause fossil carbon resources no longer contain this isotope. [3] Among polymers, which can be biobased, and in recentd ecades, much attention has been paid to polyurethanes (PUs), which are one of the most common polymers used in industry.…”

Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor

“…It has been reported that unreacted TDI is present in PUF [5,6]. However, these results have been questioned since it was not concluded whether the detected TDI stemmed from residual TDI or from foam degradation during extraction or derivatization procedures [7]. Figure 2 shows the conversion of an isocyanate to a primary amine.…”

Characterization and comparative analysis of 2,4-toluene diisocyanate and 1,6-hexamethylene diisocyanate haptenated human serum albumin and hemoglobin

“…Diisocyanates (dNCOs) are highly reactive chemicals used as cross-linking agents in the manufacture of polyurethane products such as paints, elastomers, and adhesives 1–3 . They are potent sensitizers and are a commonly reported cause of occupational chemical hypersensitivity reactions including asthma 4,5 .…”