Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances—2. Dermal sensitization potential in the mouse local lymph node assay

West, Robert J.; Burleson, Stefanie C.M.; Gulledge, Travis V.; Miller, Jason W; Chappelle, Anne H; Krieger, Shannon M.; Graham, Cynthia; Simon, Glenn S.; Plehiers, Patrick M.

doi:10.1177/07482337221089587

Cited by 4 publications

(2 citation statements)

References 39 publications

(70 reference statements)

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“…This paper reports on the design of the experimental program and the investigation of hazards to the aquatic environment. In a companion paper, the dermal sensitization potency of a broadened set of polymeric prepolymers produced from both aromatic and aliphatic diisocyanates was investigated and reported (West et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-1. Design of experiments, aquatic exposure, and acute aquatic toxicity

West¹,

Euskirchen

Neuhahn

et al. 2022

Toxicol Ind Health

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Polymeric polyisocyanate prepolymer substances are reactive intermediates used in the manufacture of various polyurethane products. Knowledge of their occupational and environmental hazard properties is essential for product stewardship and industrial hygiene purposes. This work reports on the systematic design of a program to explore how structural features (i.e., types of polymeric polyol and diisocyanate reactants, functionality) and physical–chemical properties (i.e., octanol–water partition coefficient [log Kow], viscosity, molecular weight) of a group of 10 toluene diisocyanate (TDI)- and methylene diphenyl diisocyanate (MDI)-based monomer-depleted prepolymer substances can be related to their exposure and hazard potentials. The revelation of trends or thresholds in such relationships could form a basis for regulatory screening of existing or new prepolymer substances, while also informing the design of substances having reduced exposure and/or hazard profiles. As a first step, the aquatic exposure and hazard potentials of these 10 substances were investigated. The results of this investigation showed that yields of dissolved reaction products (derived from non-purgeable organic carbon measurements and carbon contents of the parent prepolymers) were inversely correlated with the calculated log Kow of the substances. For prepolymer loading rates of both 100 and 1000 mg/L in water, the average dissolved reaction product yields ranged from ≤1% to 32% and from ≤0.1% to 25%, respectively, over calculated log Kow values ranging from −4.8 to 45. For both loading rates, dissolved reaction products were not quantifiable where the calculated log Kow value was >10. Yet, none of the 10 prepolymers and tested loading rates exhibited acute adverse effects on the aquatic invertebrate, Daphnia magna, in the 48-h acute immobilization test. From a product stewardship perspective, polymeric prepolymers of TDI and MDI within the investigated domain and concentration range are not expected to be hazardous in the aquatic environment.

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Section: Introductionmentioning

confidence: 99%

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-1. Design of experiments, aquatic exposure, and acute aquatic toxicity

West¹,

Euskirchen

Neuhahn

et al. 2022

Toxicol Ind Health

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“…Positive immunological tests correlated with exposure. , The correlation between inhalation exposure to biuret aerosol and 1,6-hexanediamine (HDA) in urine was weak, suggesting that HDA may reflect exposure to HDI monomer rather than oligomers. In addition, knowledge of oligomer metabolism ,, and their association with external exposures is lacking, thereby making HDA the only valid biomarker for HDI exposure. The maximum tolerated air concentrations at workplaces (MAK value) for the HDI monomer is 0.2 μmol/m 3 .…”

Section: Introductionmentioning

confidence: 99%

New Method to Biomonitor Workers Exposed to 1,6-Hexamethylene Diisocyanate

Sabbioni

Pugh²

2022

Chem. Res. Toxicol.

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Isocyanates such as 1,6-hexamethylene diisocyanate (HDI), 4,4′-methylenediphenyl diisocyanate, and toluene diisocyanate are highly reactive compounds that have a variety of commercial applications, including manufacturing polyurethane foam, elastomers, paints, adhesives, coatings, insecticides, and many other products. Their primary route of occupational exposure is through inhalation. Due to their high chemical reactivity, they are toxic and have adverse effects at the cellular and subcellular levels, leading to irritative and immunological reactions associated with lung disease. High concentrations of isocyanates are strong respiratory irritants. Bronchial sensitization and asthma are among the major adverse clinical reactions associated with low-level chronic exposure to isocyanates. Albumin adducts have been linked to the mechanism of occupational asthma caused by isocyanates. Isocyanates react in vivo with albumin, which is recognized by the immune system. Albumin adducts of isocyanates trigger immune responses and are probably the antigenic basis for isocyanate asthma. Sensitization to isocyanates is the main pathway for adverse health effects. Therefore, markers for the biologically effective dose such as albumin adducts of HDI are needed. A new isocyanate adduct of HDI with lysine�N ε -[(6-amino-hexyl-amino)carbonyl]-lysine (HDI-Lys)�was synthesized and characterized by 1 H-NMR, 13 C-NMR, and mass spectrometry (MS). Appropriate internal standards�HDI-Lys-4,4′-5,5′-d 4 (HDI-d 4 -Lys) and N ε -[(7amino-heptyl-amino)carbonyl]-lysine (Hep-Lys)�were synthesized to establish a LC−MS/MS method for the analysis of HDI adducts in in vitro modified albumin and in workers. The presence of HDI-Lys was found after pronase digestion of albumin and confirmed by two independent chromatographic approaches: with a C8 reversed-phase column and with a hydrophilic interaction liquid chromatography column. Quantification was performed with positive electrospray ionization (ESI)−MS. The adduct peak found in vivo was confirmed with the less sensitive negative ESI−MS. In summary, these are new compounds and methods to determine isocyanate-specific adducts with albumin in workers exposed to HDI.

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Performance study and tunnel waterproofing application of polyurethane prepolymer prepared by prepolymer and acetone combination

Yang,

He,

Zhang

2023

mat express

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Waterproof measures are an important guarantee to protect the tunnel structure and maintain its safe and reliable operation. With the continuous progress of science and technology, waterborne polyurethane (WPU) is widely used in various applications such as coatings and adhesives due to its excellent mechanical properties. With the presence of hydrophilic groups, it is necessary to chemically modify PU due to its reduced performance. The PU prepolymer was prepared using the prepolymer acetone combination method and was emulsified by the high gravity strengthening technology for a better synthetic process. The modified PU composite lotion (CL) was then prepared. When the acrylate content increased, the two parameters, i.e., the size and particle size distribution of PU CL, showed opposite trends. For instance, the size changed from 61.45 nm to 106.5 nm, and the particle size distribution index changed from 0.255 to 0.11. Furthermore, the compressive strength of the material is 13.7 Mpa. When the acrylate content gradually increases, the material tensile strength changes from 11.9 MPa to about 6.5 MPa, and the overall elongation at break remains within 200%–250%. In the actual test of tunnel waterproofing (TW), the water absorption rate of the modified polyurethane changes slightly and is generally kept in the range of 4%–4.5%. It has a good waterproof effect, providing a new method reference for PU CL modification and TW.

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Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances—2. Dermal sensitization potential in the mouse local lymph node assay

Cited by 4 publications

References 39 publications

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-1. Design of experiments, aquatic exposure, and acute aquatic toxicity

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-1. Design of experiments, aquatic exposure, and acute aquatic toxicity

New Method to Biomonitor Workers Exposed to 1,6-Hexamethylene Diisocyanate

Performance study and tunnel waterproofing application of polyurethane prepolymer prepared by prepolymer and acetone combination

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