1,3-Bis(1-isocyanato-1-methylethyl)benzene

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 9,000(SRC), determined from a structure estimation method(2), indicates that 1,3-bis(1-isocyanato-1-methylethyl)benzene is expected to be immobile in soil(SRC). However, since isocyanates hydrolyze rapidly in water(3), soil mobility, biodegradation, and other fate processes of 1,3-bis(1-isocyanato-1-methylethyl)benzene are not expected to be important fate process(SRC). Volatilization of 1,3-bis(1-isocyanato-1-methylethyl)benzene from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(4) 1,3-bis(1-isocyanato-1-methylethyl)benzene is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.2X10-3 mm Hg, determined from a fragment constant method(5).

AQUATIC FATE: Since isocyanates hydrolyze rapidly in water(1), biodegradation, aquatic bioconcentration, volatilization and adsorption to sediment of 1,3-bis(1-isocyanato-1-methylethyl)benzene are not expected to be important fate processes(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,3-bis(1-isocyanato-1-methylethyl)benzene, which has a vapor pressure of 3.2X10-3 mm Hg at 25 °C(SRC), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,3-bis(1-isocyanato-1-methylethyl)benzene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 13 hours (SRC), calculated from its rate constant of 1.0X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2) 1,3-Bis(1-isocyanato-1-methylethyl)benzene does not contain chromophores that absorb at wavelengths >290 nm(3) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Skin Sensitizer - An agent that can induce an allergic reaction in the skin.；Asthma - Reversible bronchoconstriction (narrowing of bronchioles) initiated by the inhalation of irritating or allergenic agents.；Fibrogenic - Inducing tissue injury and fibrosis (scarring).

IDENTIFICATION AND USE: 1,3-Bis(1-isocyanato-1-methyl)benzene is a clear colorless liquid at room temperature. It is insoluble and reacts with water. It is used for the production of polyurethane formed plastics, elastomers, duromers and adhesives. It is also used in specialty coatings, aqueous dispersions, herbicide coatings, adhesives, thermoplastic urethanes and lacquers. Other common commercial products include fabric and leather finishes, adhesives, automotive paints, printing inks, sealants and wood coatings. It is used in injection moldings, surface coatings and cast elastomers in polyurethane industry. HUMAN EXPOSURE AND TOXICITY: In facilities than manufacture or use 1,3-Bis(1-isocyanato-1-methylethyl)benzene employees were evaluated using immunoglobulin (Ig) and IgG serum antibody enzyme linked immunosorbent assay (ELISA) studies. No work related asthma was noted. However, there were some irritant symptoms, mainly respiratory or ocular. This chemical is a skin and eye irritant. Occupational exposure to this chemical can result from dermal contact or inhalation where this chemical use used or produced in the workplace. ANIMAL STUDIES: In rats the LD50 oral dose is 4,600 mg/kg; LD50 Guinea Pigs inhalation is 240 mg/cu m/1 hr.

American Cyanamid Co.; Acute toxicity of m-TMXDI to Daphnia magna with cover letter dated 08/03/87. EPA Document No. 86-870000781, Fiche No. OTS0515220.

American Cyanamid Co.; Acute toxicity of m-TMXDI to fathead minnows (Pimephales promelas) with cover letter dated 08/03/87. EPA Document No. 86-870000782, Fiche No. OTS0515221.

American Cyanamid Co.; The acute toxicity of inhaled m-TMXDI in the guinea pig with cover letter dated 08/03/87. EPA Document No. 86-870000783, Fiche No. OTS0515222.

American Cyanamid Co.; Range-finding study with inhaled m-TMXDI in guinea pigs with cover letter dated 08/03/87. EPA Document No. 86-870000784, Fiche No. OTS0515223.

For more TSCA Test Submissions (Complete) data for 1,3-BIS(1-ISOCYANATO-1-METHYLETHYL)BENZENE (22 total), please visit the HSDB record page.

/SURVEILLANCE/ ...96 workers employed at facilities that manufacture or use TMXDI (meta) aliphatic isocyanate and TMI (meta) unsaturated aliphatic isocyanate /were evaluated using/ immunoglobulin (Ig) and IgG serum antibody enzyme-linked immunosorbent assay (ELISA) studies and a questionnaire designed to identify symptoms compatible with work-related syndromes such as asthma and hypersensitivity pneumonitis. There were no workers with immunologically induced disease due to TMI isocyanate or TMXDI isocyanate nor were there any workers whose questionnaires suggested new onset of asthma. Approximately 40% of workers experienced some irritant symptoms, mostly upper respiratory or ocular. One worker had low level IgE antibody against TMXDI-HSA but had no work-related respiratory symptoms. Very low-level IgG against TMI-HSA or TMXDI-HSA was present in 7% of workers, all of whom were in the high-exposure category.

1,3-Bis(1-isocyanato-1-methylethyl)benzene's production and use in coatings, dispersions, inks, sealants, adhesives, lacquers, and paints(1) may result in its release to the environment through various waste streams. Its use in wood coatings(1) in particular may result in its direct release to the environment(SRC).

AEROBIC: 1,3-Bis(1-isocyanato-1-methylethyl)benzene was not found to be readily biodegradable by the OECD Closed Bottle Test. A solution of 1,3-bis(1-isocyanato-1-methylethyl)benzene was inoculated with a low concentration of activated sludge from a mixed population and kept in closed bottles in the dark at a constant temperature of 20 °C. The degradation was followed by oxygen analyses over a 28-day period. A parallel control with inoculum, but without test material, was run as a blank correction factor. The procedure was validated by means of a reference substance (aniline) of known biodegradability. Degradation after 28-days was determined to be 13.7% as compared to 95% for the aniline reference material. Because a level of 70% was not reached, this substance is not "Readily Biodegradable" by this test procedure(2). Due to the rapid hydrolysis of isocyanates, the test probably is for the diamine hydrolysis product(SRC).

The rate constant for the vapor-phase reaction of 1,3-bis(1-isocyanato-1-methylethyl)benzene with photochemically-produced hydroxyl radicals has been estimated as 1.01X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 13 hours(SRC) at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 1,3-Bis(1-isocyanato-1-methylethyl)benzene, similar to most isocyanates(2-5), is expected to hydrolyze in aqueous solution(SRC). In water, the isocyanate group is expected to react to form an unstable acid intermediate followed by further hydrolysis to form an amine or insoluble ureas(5). The measured hydrolysis half life of 1,3-bis(1-isocyanato-1-methylethyl)benzene at pH 7 is 0.4 hours at 25 degrees C(6). Anionic homopolymerization can also occur yielding high molecular weight cross-linked isocyanates(2). 1,3-Bis(1-isocyanato-1-methylethyl)benzene does not contain chromophores that typically absorb at wavelengths >290 nm(7) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Occupational exposure to 1,3-bis(1-isocyanato-1-methylethyl)benzene may occur through dermal contact or inhalation of this compound at workplaces where 1,3-bis(1-isocyanato-1-methylethyl)benzene is produced or used. Exposure to 1,3-bis(1-isocyanato-1-methylethyl)benzene among the general population is not expected due to the rapid hydrolysis when exposed to water in the environment but limited exposure may be present during the use of commercial products containing this compound. (SRC)

Chemical: Benzene, 1,3-bis(1-isocyanato-1-methylethyl)-

Hazard Traits - Bioaccumulation; Environmental Persistence; Respiratory Toxicity；Authoritative List - Canada PBiTs; EC Annex VI Resp. Sens. - Cat. 1；Report - if used as a fragrance or flavor ingredient

Benzene, 1,3-bis(1-isocyanato-1-methylethyl)- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Benzene, 1,3-bis(1-isocyanato-1-methylethyl)- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

PMN - indicates a commenced PMN (Pre-Manufacture Notices) substance.

Status: Active Update: 15-06-2020 https://echa.europa.eu/registration-dossier/-/registered-dossier/22792

Restricted substance: 1,3-bis(1-isocyanato-1-methylethyl)benzene；EC: 220-474-4；Restriction condition document: PDF link

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Benzene, 1,3-bis(1-isocyanato-1-methylethyl)- is included on this list. Effective date 6/1/87; Sunset date: 11/9/93.