DBNPA

DBNPA

CAS No. : 10222-01-2
EC No. : 233-539-7

Synonyms:
2,2-Dibromo-2-cyanoacetamide; Dibromocyano acetic acid amide; 2,2-Dibromo-3-nitrilopropionamide; 2,2-dibromo-3-nitrilopropionamide; Cyanoacetamide; 2.2-dibromo-3-nitrilopropionamide; 2,2-DIBROMO-2-CYANOACETAMIDE; 10222-01-2; Dibromocyanoacetamide; 2,2-Dibromo-3-nitrilopropionamide; Dbnpa; Acetamide, 2,2-dibromo-2-cyano-; 2-Cyano-2,2-dibromoacetamide; XD-7287l Antimicrobial; 2,2-Dibromo-2-carbamoylacetonitrile; Caswell No. 287AA; UNII-7N51QGL6MJ; NSC 98283; Dibromocyano acetic acid amide; XD-1603; HSDB 6982; XD 7287L; EINECS 233-539-7; EPA Pesticide Chemical Code 101801; BRN 1761192; 7N51QGL6MJ; Acetamide, 2-cyano-2,2-dibromo-; Dibromonitrilopropionamide; 2,2-dibromo-2-cyano-acetamide; Cyanodibromoacetamide; DBNP; 3-02-00-01641 (Beilstein Handbook Reference); KSC174K7F; Acetamide,2-dibromo-2-cyano-; ACMC-20980y; 2-Cyano-2,2-dibromo-Acetamide; CHEMBL1878278; DTXSID5032361; DBNPA; ZINC1638458; 2,2, Dibromo 3-Nitrilopropionamide; 2,2-dibromo-3-nitrilopropion amide; SBB008529; 2,2-Dibromo-2-cyanoacetamide, 9CI; 2, 2-Dibromo-2-carbamoylacetonitrile; 2,2-Dibromo-2-cyanoacetamide, 96%; AKOS015833850; 2,2-bis(bromanyl)-2-cyano-ethanamide; LS-3155; DBNPA; CAS-10222-01-2; DB-027512; D2902; FT-0612090; 2,2-Dibromo-3-Nitrilo propionamide (DBNPA); BE 3S; DBNPA;D-244; DBNPA1; BIOBRO; Busan 94; DBNPA20%; NSC 98283; DBNPA 7287; Mucosin NT; 2,2-Dibromo-2-cyanoacetamide; Dibromocyano acetic acid amide; 2,2-Dibromo-3-nitrilopropionamide; 2,2-dibromo-3-nitrilopropionamide; Cyanoacetamide; 2.2-dibromo-3-nitrilopropionamide; 2,2-DIBROMO-2-CYANOACETAMIDE; 10222-01-2; Dibromocyanoacetamide; 2,2-Dibromo-3-nitrilopropionamide; Dbnpa; Acetamide, 2,2-dibromo-2-cyano-; 2-Cyano-2,2-dibromoacetamide; XD-7287l Antimicrobial; 2,2-Dibromo-2-carbamoylacetonitrile; Caswell No. 287AA; Acetamide, 2-cyano-2,2-dibromo-; Dibromonitrilopropionamide; 2,2-dibromo-2-cyano-acetamide; Cyanodibromoacetamide; DBNP; 3-02-00-01641 (Beilstein Handbook Reference); NSC 98283; Dibromocyano acetic acid amide; 2,2-Dibromo-3-nitrilopropionamide

DBNPA

DBNPA or 2,2-dibromo-3-nitrilopropionamide is a quick-kill biocide that easily hydrolyzes under both acidic and alkaline conditions. It is preferred for its instability in water as it quickly kills and then quickly degrades to form a number of products, depending on the conditions, including ammonia, bromide ions, dibromoacetonitrile, and dibromoacetic acid. DBNPA acts similar to the typical halogen biocides.
DBNPA is used in a wide variety of applications. Some examples are in papermaking as a preservative in paper coating and slurries. It is also used as slime control on papermachines, and as a biocide in hydraulic fracturing wells and in cooling water.

Technical Grade 2.2-dibromo-3-nitrilopropionamide.
Only registered for non-fifra use in the US
Quick-kill biocide.
Controls bacteria, fungi and algae in industrial processes and water systems including: paper mills, industrial cooling water systems.
Controls slime-formation in air washer systems.
Use biocides safely. Always read the label and product information before use.

Biocides may be used to control biofouling in spiral-wound reverse osmosis (RO) and nanofiltration (NF) systems. The objective of this study was to investigate the effect of biocide 2,2-dibromo-3-nitrilopropionamide (DBNPA) dosage on biofouling control. Preventive biofouling control was studied applying a continuous dosage of substrate (0.5 mg/L) and DBNPA (1 mg/L). Curative biofouling control was studied on pre-grown biofilms, once again applying a continuous dosage of substrate (0.5 mg acetate C/L) and DBNPA (1 and 20 mg/L). Biofouling studies were performed in membrane fouling simulators (MFSs) supplied with biodegradable substrate and DBNPA. The pressure drop was monitored in time and at the end of the study, the accumulated biomass in MFS was quantified by adenosine triphosphate (ATP) and total organic carbon (TOC) analysis. Continuous dosage of DBNPA (1 mg/L) prevented pressure drop increase and biofilm accumulation in the MFSs during a run time of 7 d, showing that biofouling can be managed by preventive DBNPA dosage. For biofouled systems, continuous dosage of DBNPA (1 and 20 mg/L) inactivated the accumulated biomass but did not restore the original pressure drop and did not remove the accumulated inactive cells and extracellular polymeric substances (EPS), indicating DBNPA dosage is not suitable for curative biofouling control.

DBNPA is a non-oxidative agent, rapidly degrading in alkaline aqueous solutions [16]. The organic water content as well as light enhance the hydrolysis and debromination of DBNPA into cyanoacetamide followed by degradation into cyanoacetic acid and malonic acid, that are non-toxic compounds [17]. This degradation pathway makes the use of DBNPA relatively environmentally friendly. DBNPA is compatible with polyamide based membranes and shows high rejection rates for RO membranes [18]. The antimicrobial effect is due to the fast reaction between DBNPA and sulfur-containing organic molecules in microorganisms such as glutathione or cysteine [19–21]. The properties of microbial cell-surface components are irreversibly altered, interrupting transport of compounds across the membrane of the bacterial cell and inhibiting key biological processes of the bacteria [19,20,22]. To assess the anti-biofouling effect, on-line and off-line applications of the biocide have been studied on industrial scale RO installations with a 20 ppm DBNPA concentration in the feed water. Industrial case studies described by [18] indicate a preventive effect of the biocide, but many details were not given. Only very limited information on the suitability of DBNPA to control membrane biofouling under well-defined conditions is available. The objective of this study was to determine, under well-controlled conditions, the effect of biocide DBNPA dosage on biofouling control in membrane systems. Preventive and curative biofouling control strategies were investigated in a series of experiments with membrane fouling simulators operated in parallel, fed with feed water supplemented with DBNPA (1 or 20 mg/L) and a biodegradable substrate
sodium acetate. A higher substrate concentration in feed water has shown to result in a faster and larger pressure drop increase and a higher accumulated amount of biomass [23–26]. In the studies acetate was dosed as substrate to enhance the biofouling rate. The pressure drop was monitored and autopsies were performed to quantify the accumulated material.

It is understood in the membrane industry that thin film composite polyamide membranes have limited resistance to chlorine based oxidants. Therefore, operators have relatively few options regarding chemicals which can be safely used to disinfect RO/NF systems and prevent biogrowth/biofouling. One option is the chemical, 2,2-Dibromo-3-nitrilopropionamide (DBNPA), which is a fastacting, non-oxidizing biocide which is very effective at low concentrations in controlling the growth of aerobic bacteria, anaerobic bacteria, fungi and algae.
DBNPA is an advantageous disinfectant since it also quickly degrades to carbon dioxide, ammonia and bromide ion when in an aqueous environment. This allows the effluent to be safely discharged even in sensitive water bodies. It is degraded by reactions with water, nucleophiles, and UV light (rate is dependent on pH and temperature). The approximate half-life is 24 hr @ pH 7, 2 hr @ pH 8, 15 min @ pH 9. The vast majority of microorganisms that come into contact with it are killed within 5 to 10 minutes.

Broad Spectrum Non Oxidising Biocide:
Active Ingredients:  2,2-Dibromo-3-NitriloPropionamide (DBNPA) 98% min.assay.  Highly effective against a wide range of common water borne organisms with proven efficacy against Legionella. Accepta 6404 will control these organisms and help to control microbiological fouling.
Accepta 6404 is designed for use in open cooling water systems, chilled water systems, process systems and other industrial water systems. DBNPA has proven efficacy against pathogenic microorganisms including Legionella, at levels required by the system, L8 (HS(G) 274), system water type, along with risk assessment data.
Accepta 6404 degrades rapidly and naturally at increased pH & temperature levels and as such Accepta 6404 is the product of choice for systems operating under strict environmental and discharge regulations.
The ultimate degradation products are carbon dioxide, ammonia, & bromide ion. Increasing cooling water alkalinity presents a problem for most water treatment biocides. However, for Accepta 6404 even at higher pH values, rapid & effective microbial control is achieved before any significant degradation occurs. Ideal for quick, antimicrobial activity, but rapid degradation of the microbiocide for minimal environmental impact.
Recommended contact time for biological control is 4 hours minimum at the target residual.

HOW MUCH TO USE
Accepta 6404 application rates for industrial recirculating cooling water systems will depend upon the conditions of the system prior to treatment initiation.
1.02g of Accepta 6404 will add 1ppm of DBNPA to 1000lt of system water.
Target Residual (ppm) x 1.02 x System Volume (m3) = dose required (g)
DBNPA shot dosed at 2-5ppm active is proven to control legionella in the planktonic phase with a contact time of 2-3 hours.
DBNPA shot dosed at 10-15ppm active is proven to control both planktonic and sessile legionella colonies with a contact time of 4-6 hours
DBNPA dosed to maintain a constant level of 1-2ppm active is proven to be effective at controlling legionella in the planktonic and sessile phase.
Accepta 6404 can be tested and controlled by ATP, DBNPA biocide test kit or by measuring direct control through colony counts.

PROPERTIES
Appearance: Solid – white/yellow powder
Odour: characteristic/pungent
HANDLING AND STORAGE
Accepta 6404 should be in a cool dry area.  Properly stored, the product will remain effective for 24 – 36 months.  Consult Safety Data Sheet for further information.

PACKAGING
Accepta 6404 is available in 2.5 kg jars (4 jars per case)
FEEDING
Feed Accepta 6404 using an Accepta board system.
Available in three types:
Gravity Fed – No pump needed, requires controller relay or timer
Electronic Level Control – Pump needed
Mechanical – Pump needed
2,2-dibromo-3-nitrilopropionamide

DBNPA Biocide
DBNPA is a highly effective, environmentally friendly biocide. It provides a quick kill while also quickly degrading in water. The final end product is carbon dioxide and ammonium bromide. AMSA recommends and sells DBNPA for use with DTEA II™ under appropriate conditions.

Product formulations
DBNPA Liquid (5% and 20% solutions)
For applications in water treatment, pulp and paper, reverse osmosis, oil and gas, and metalworking fluid applications
Solid, slow release tablet (40% DBNPA)
DBNPA slow release tablets are very cost effective, and require no metering equipment or special feeders. Under normal conditions one tablet can last up to 3 weeks! Designed for small cooling towers. More …
DBNPA Chemistry
Chemical name: 2,2-dibromo-3-nitrilopropionamide

Compatibility with other water treatment chemicals and water conditions: DBNPA is compatible with other treatment chemicals with the exception of mercaptobenzothiazole. It also is not compatible with ammonia or hydrogen sulfide-containing water. DBNPA maintains reliable control in systems running at acidic, neutral, or alkaline pH.
Degradation in water: DBNPA degrades quickly in aqueous environments. At neutral pH, its half-life is about nine hours (Exner, Burk, and Kyriacou: Rates and Products of Decomposition of 2,2-dibromo-3-nitrilopropionamide, J. Agr. Food Chem., Vol. 21, 1973, pp. 838–842). Continuous biocide release by the tablet maintains concentrations effective for control in the tower, while the biocide in the blowdown discharge degrades quickly. So it’s easy to meet strict environmental regulations on tower discharge.
Is DBNPA an oxidizer?
DBNPA is not an oxidizing biocide and it is not a bromine release biocide. DBNPA does act similar to the typical halogen biocides.

This Reregistration Eligibility Decision (RED) addresses pesticide uses of 2,2-dibromo-3- nitrilopropionamide (DBNPA). Products containing this active ingredient are used to control microorganisms including algae, bacteria, and fungi in various industrial processes. The Agency has completed its review of the target database for DBNPA and has concluded that most uses of DBNPA as labeled and used as specified in this Reregistration Eligibility Decision will not pose unreasonable risks or adverse effects to humans or the environment. However, because the risk to non-target aquatic organisms from the discharge of industrial effluent containing DBNPA outweighs the potential benefits of the pesticidal use of DBNPA in single flow-through cooling towers, the Agency has concluded that this use is ineligible for reregistration. The Agency intends to take appropriate regulatory steps to adequately address the potential risk of this use.

After evaluation of all available ecotoxicological and environmental data and subsequent consultation with the Agency's Offices (Office of Water and the Office of Toxic Substances), it was determined that aquatic risk concerns for all currently registered uses except single flowthrough cooling systems may be adequately mitigated by secondary biological treatment of industrial effluent. Ecotoxicological and environmental fate data indicate that DBNPA degrades rapidly by anaerobic and aerobic aquatic metabolism into less toxic degradates. Secondary biological treatment is required for all aquatic industrial uses except, 1) waste water treatment systems, 2) secondary oil recovery systems, and 3) single flow-through cooling tower systems (ineligible for reregistration). Biological treatment is not required for waste water treatment systems because biological degradation readily occurs in these systems. Although secondary biological treatment is not feasible for secondary oil recovery systems, an evaluation of the
secondary oil recovery use pattern as it relates to DBNPA sufficiently reduces the Agency's concern with this use pattern. However, aquatic risk concerns for the single flow-through cooling system use of DBNPA cannot be mitigated. Single flow-through cooling systems represent a direct surface water discharge situation and a potential adverse risk to aquatic species remains. Additionally, the Agency has a concern for the potential effect of DBNPA on human developmental toxicity. In an oral developmental toxicity study in rabbits, DBNPA was observed to produce fetal structural alterations at a dose (30 mg/kg/day) which was not maternally toxic. The NOEL for developmental effects was 10 mg/kg/day and the maternal NOEL was 30 mg/kg/day. There is a potential for mixer/loader/applicator exposure from use. Margin of Exposures (MOE) are acceptable (greater than 100) for all uses regulated by the EPA except one, that of the handler using an open pouring method to add DBNPA to cooling towers (MOE = 28). The Agency is therefore requiring use of personal protective equipment for open pouring for recirculating cooling water tower uses. The potential for post-application acute exposure is minimal. A food tolerance has been established for DBNPA for food contact with food grade paper and paperboard (21 CFR 176.300). The use of DBNPA for this purpose is regulated under the jurisdiction of the U.S. Food and Drug Administration.

This paper discusses the use of the non-oxidative biocide 2,2-dibromo-3-nitrilopropionamide (DBNPA) to minimize and/or eliminate problems due to biofouling accumulation and to ensure long-term performance of a RO system. DBNPA is a suitable biocide due to its compatibility with reverse osmosis (RO) membranes. Our aim is to present a better understanding of DBNPA, its rejection by common RO membrane types and the environmental chemistry concepts for residual DBNPA and its by-products in the outlet concentrate stream. The application areas covered are industrial water and off-line drinking water systems. Examples of field studies conducted on fullscale RO systems that use DBNPA will be shown. Also discussed are the data obtained from the analysis that was carried out to determine the degradation of DBNPA in the RO feed and outlet stream. The benefits of using DBNPA for biofouling prevention include reducing the required feed pressure and the cleaning frequency of the RO system. Other benefits are reduced cleaning chemical costs, reduced downtime of the plant and reduced time of the operators. This results in increased output of the plant and reduced operating expenses of the RO operation.

This degradation pathway makes the use of DBNPA relatively environmentally friendly. DBNPA is compatible with polyamide based membranes and shows high rejection rates for RO membranes [18]. The antimicrobial effect is due to the fast reaction between DBNPA and sulfur-containing organic molecules in microorganisms such as glutathione or cysteine. 
To assess the anti-biofouling effect, on-line and off-line applications of the biocide have been studied on industrial scale RO installations with a 20 ppm DBNPA concentration in the feed water. Industrial case studies described by [18] indicate a preventive effect of the biocide, but many details were not given. Only very limited information on the suitability of DBNPA to control membrane biofouling under well-defined conditions is available.
80 DBNPA, a biocide, often used in hydraulic fracturing operations, is also efficiently removed by RO membranes (rejection of 98.5−99.5%). 81 DBNPA is even recommended for usage as an antifouling agent in drinking water treatment. 81 At the same time, low molecular weight semivolatile 2butoxyethanol was not rejected with ASF-99 RO membrane characterized by high NaCl rejection.

IDENTIFICATION: 2,2-Dibromo-3-nitrilopropionamide (DBNPA) is an off-white crystalline solid with a mild medicinal antiseptic odor. It is slightly volatile, very soluble in water, and corrosive. USE: DBNPA is used to control bacteria, fungi and slime-forming algae in cooling water systems, evaporative condensers and heat exchangers, air washing systems, pulp mill and paper manufacturing, and oil extraction drilling fluids. It also is used as a preservative in paints, industrial coatings and adhesives, metalworking cutting fluids, and paper and paper products. EXPOSURE: Industrial workers handling fluids with DBNPA may be exposed through dermal contact and inhalation exposure to mists. U.S. workers handling disinfectant solutions containing the compound are required to wear protective clothing and chemical-resistant gloves and aprons. 2,2-Dibromo-3-nitrilopropionamide released to the environment will be degraded in air and by exposure to direct sunlight. DBNPA is expected to move through soil. It will chemically break down quickly in water. DBNPA also will be degraded by microorganisms. It is not likely to build up in aquatic organisms. RISK: People accidently exposed through spills or compound misuse of 2,2-dibromo-3-nitrilopropionamide reported eye, throat and respiratory irritation, runny nose, and headache. Allergic skin reactions may develop in some people following direct contact to DBNPA. Direct contact with 2,2-dibromo-3-nitrilopropionamide may damage eyes and skin due to its corrosiveness. Labored breathing and weight loss were observed in laboratory animals repeatedly given high oral doses. Repeated skin exposure of laboratory animals to high doses of DBNPA caused skin damage. Very high oral doses given laboratory animals during pregnancy caused decreased weight gain, and some of the animals died. Skeletal birth defects were found in some offspring of surviving maternal animals exposed to this dose, and a lower, maternally non-toxic dose. The potential of DBNPA to cause cancer in laboratory animals has not been tested. The potential for DBNPA to cause cancer in humans has not been assessed by the U.S. EPA IRIS program, the International Agency for Research on Cancer, or the U.S. National Toxicology Program 13th Report on Carcinogens.

Based on the reviews of the generic data for the active ingredient DBNPA the Agency has sufficient information on the health effects of DBNPA and on its potential for causing adverse effects in fish and wildlife and the environment. Therefore, the Agency concludes that specific products containing DBNPA for all uses except single flow-through cooling tower uses are eligible for reregistration when labeled and used as specified in this Reregistration Eligibility Decision, since they will not pose unreasonable risks or adverse effects to humans or the environment.
USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document - 2,2-Dibromo-3-nitrilopropionamide (DBNPA) EPA 738-R-94-026 (September 1994). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Dibromo-3-nitrilopropionamide (DBNPA) is found on List C. Case No: 3056; Pesticide type: fungicide, herbicide, antimicrobial; Case Status: RED Approved; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): dibromo-3-nitrilopropionamide; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) for the case/AI.

IDENTIFICATION AND USE: 2,2-Dibromo-3-nitrilopropionamide (DBNPA) is white to "off white" crystalline solid. It is used as a pesticide(Trade Names: DBNPA, Slimicide 508, XD-7287L Antimicrobial, XD-1603.) Main uses include the following: algicide, bactericide and fungicide; preservative used mainly in pulp, paper and paperboard mill water systems and in industrial water cooling systems. It is also used as a preservative in animal glues, metalworking cutting fluids, oil recovery drilling muds, latex paints, resin/latex/polymer emulsions, latex/oil/varnish paints, and paper and paper products. HUMAN EXPOSURE AND TOXICITY: Several human incident reports concerning DBNPA are on file with the EPA. These include eye, throat, & respiratory irritation, runny nose, & headache. Generally the effects arose with spills or misuse. No treatment related effects on chromosome aberrations in proliferating cultured human lymphocyte were reported with or without metabolic activation. ANIMAL STUDIES: A primary eye irritation study in rabbits resulted in severe corneal damage. Dermal irritation was noted in rats of both sexes. Renal tubular alterations of the kidneys (minimal cytoplasmic swelling and vacuolization) were described in female rats. Developmental study in rabbits found retarded ossification of several fetal skeletal elements. The occurrence of structural alterations at a maternally non-toxic dose indicates that DBNPA is a developmental toxicant in rabbits. DBNPA did not induce micronuclei formation in mice. In Salmonella typhimurium TA98, TA100, TA1535, and TA1537 and Escherichia coli WP2uvrA the test material did not produce a positive increase in the number of revertants per plate of any of the test strains either in the presence or absence of microsomal activation. The positive controls were functional. Sister chromatid exchange (SCE) assay in Chinese hamster ovary cells after one hour exposures at DBNPA was negative.

Several human incident reports concerning DBNPA are on file with the /EPA/. These include eye, throat, & respiratory irritation, runny nose, & headache. Generally the effects arose with spills or misuse.
Acute Exposure/ A primary eye irritation study in rabbits resulted in severe corneal damage, which was considered permanent; in all treated rabbits DBNPA was corrosive to the eyes, with max opacity within 1 hr. Rabbits treated with DBNPA in a primary dermal irritation study (4 hr exposure to 0.5 g) experienced erythema & edema, with exfoliation after five days. Two dermal sensitization studies with guinea pigs found DBNPA to be a weak sensitizer.
Subchronic or Prechronic Exposure/ In a subchronic toxicity study, rats were given DBNPA for 90 days by gavage at doses of 0, 5, 13, or 30 mg/kg/day. The NOEL was 5 mg/kg/day. The LOEL was 13 mg/kg/day based on dyspnea at this dose & higher. The animals with dyspnea also had weight loss & some of them died. Doses of 0, 103, 309, or 1031 mg/kg/day of DBNPA were applied to the skin of rats (6 hrs/day; 5 days/wk) for 90 days. The systemic NOEL was 309 mg/kg/day. The systemic LOEL was 1031 mg/kg/day based on clinical chemistry findings of reduced triglyceride levels in males, reduced cholesterol as well as elevated alkaline phosphatase & chloride in females, & urine pH at or above 9 in some males. The dermal irritation NOEL was 103 mg/kg/day. Dermal irritation (erythema &/or edema) was transient in several rats of both sexes at the two highest doses.

Subchronic or Prechronic Exposure/ 2,2-Dibromo-3-Nitrilopropionamide (DBNPA, XD-1603L, 95.7% stated purity, run 09020-24) was given at 0, 20, 100, or 500 ppm in the drinking water (pH 4 or pH 8) for 90 days to 10 Sprague- Dawley Spartan rats/sex/group. DBPNA is unstable at pH 8 and exposure was to breakdown products. The only treatment related effect of toxicological concern was minimal renal tubular alterations of the kidneys (minimal cytoplasmic swelling and vacuolization) in female rats maintained at 500 ppm, at pH 8 (NOEL = 100, pH 8; male, 8 mg/kg/day; female 15.9 mg/kg/day).
Subchronic or Prechronic Exposure/ A 20% solution of DBNPA (lot MM890624, tetraethylene glycol vehicle) was applied undiluted for 6 hr/day, 5 days/week for 13 weeks to a 5 X 5 cm clipped patch (occluded) on the backs of 10 Fischer 344 rats/sex/group at 0, 103, 309, or 1031 mg/kg/day (0.0, 0.4, 1.2 or 4.0 mL/kg/day). Adequate ophthalmology, hematology, clinical chemistry, and urinalysis were performed with no treatment-related findings. A modified FOB was also included. Treatment related responses were localized to the application site: transient dermal irritation at 309 mg/kg/day and dermal irritation, erythema, edema, scabs, hyperkeratosis and inflammation at 1031 mg/kg/day (dermal NOEL = 103 mg/kg/day, systemic NOEL > or =1031 mg/kg/day).

An important environmental feature of 2,2-dibromo-3-nitrilopropionamide (DBNPA), the active ingredient in Dow's Antimicrobials 7287 and 8536 is that the compound rapidly degrades in dilute aqueous solutions. High performance liquid chromatography analyses of ppm-concentrations of DBNPA and its degradation products in laboratory tests of several natural water samples were used to follow the reactions involved. A hydrolysis pathway leads to dibromoacetonitrile (DBAN) and other products. The presence of organic material in the water leads to degradation by a second pathway in which monobromonitrilopropionamide (MBNPA) and several other degradation products are formed. From the data, a computer simulation model of the reactions has been developed using DACSL (Dow Advanced Continuous Simulation Language). The model describes quantitative relationships of DBNPA dosage and the natural water's organic material content, as measured by total organic carbon (TOC), in the degradation pathways of DBNPA. The model helps interpret the aquatic toxicity of the rapidly changing complex mixture produced during these degradations. Simulations of the DBNPA treatment of cooling towers were compared to limited experimental data which indicated that most of the degradation occurred by the pathway which produced the less toxic products (MBNPA et seq. rather than DBAN et seq.)

2,2-Dibromo-3-nitrilopropionamide (DBNPA) has been documented as a useful antimicrobial agent in a number of industrial applications, due to its rapid rate of kill at relatively low use-concentrations, broad spectrum of antimicrobial activity, chemical non-persistence, and low environmental impact. It is available commercially as a 20% active solution in a water/polyethylene glycol blend. A discussion on the use of a non-oxidizing, fast-acting antimicrobial agent with a short chemical half-life, in various aspects of metalworking-fluid production and utilization, presented at the 59th STLE Annual Meeting (Toronto, Ontario, Canada 5/17-20/2004), covers lubricant degradation/stability-microbial; indirect food-contact approvals for DBNPA; decomposition pathways; microbiology; DBNPA as a preservative enhancer; efficacy of DBNPA; and methods of addition of DBNPA to water-based systems.
The present invention provides an essentially pure compacted 2,2-Dibromo-3-nitrilopropionamide (DBNPA) in a granular and/or tablet and/or briquette and/or pellet form. The present invention further provides a process for preparing the same essentially pure compacted DBNPA.

FIELD OF THE INVENTION
The present invention relates to compacted forms of 2,2-Dibromo-3-nitrilopropionamide (DBNPA), namely a granular and/or a tablet and/or a briquette and/or a pellet form that each has distinguished commercial and technological advantages over same material in the known powder form.

BACKGROUND OF THE INVENTION
2,2-Dibromo-3-nitrilopropionamide (DBNPA) is a biocide which is used in industrial water treatment, cooling systems and paper mills. DBNPA is an efficient biocide with a rapid microbiocidal broad-spectrum activity, especially in water systems that contain high organic loads.
The main current application of DBNPA is as a liquid formulation, which contains a mixture of water and an organic solvent such as a glycol (for example, polyethylene glycol (PEG), dipropylene glycol (DPG), ethylene glycol, etc.) and others. The active ingredient (DBNPA) is only 5-25% of such liquid formulation. The addition of an organic solvent is required for dissolution of the relatively water-insoluble DBNPA into a liquid formulation.
Prior art teaches the production of DBNPA as a powdered material which can be used for the preparation of a liquid or solid formulation.

Several types of sustained-release compositions containing DBNPA have been described:
1) EP 285 209 recites a solid sustained release antimicrobial composition (in a tablet form), comprising 1 to 90% by wt of a halogenated amide (including DBNPA) antimicrobial agent, 10 to 80% by wt of a hydrophilic polymer, 0 to 80% by wt of a compression agent and 0 to 10% by wt of a mold release agent. A composition comprising 40% DBNPA, 30% Methocel (water soluble cellulose polymer), 27% CaHPO4 (as compressing agent) and 3% stearic acid, was specifically demonstrated.
2) WO 98/25458 discloses a solid sustained-release tablet consisting of DBNPA admixed with a water-soluble natural or synthetic polymer. Besides the addition of a synthetic polymer into the formulation, the tablet is coated with an additional water-soluble cellulosic polymer.
3) WO 99/18162 discloses a biocidal powder coating composition comprising thermoplastic and/or thermosetting resins based on epoxy, polyester, acrylic or polyurethane resins. The biocide used is a liquid bio-active material (including DBNPA) and/or specially selected solid bio-active materials (for example, solid thiazine-thiones, thiolphthalimides, and others). The biocides are homogeneously mixed or bonded with the particles of the powder.
The process of preparing said biocidal powder coating composition is characterized by blending the components of the powder coating composition in a premixer, followed by feeding the mixture into an extruder, heating to a temperature high enough to melt and mix most of the major components, and cooling to a solid form.
4) EP 953 284 discloses a composition (in a tablet form) for delivering the DBNPA biocide to an oil field fracturing fluid, comprising effervescing agents such as sodium bicarbonate, citric acid and borax. The composition comprises about 35-65% DBNPA, about 15-28% sodium carbonate, 15-27% citric acid and up to about 20% borax.
5) EP 954 966 recites controlled release compositions comprising a biologically active compound, including DBNPA, and a hydroxystyrene polymer (e.g. hydroxystyrene homopolymer, methylhydroxystyrene homopolymer, halohydroxystyrene homopolymer and their copolymers). The weight ratio of DBNPA to the polymer is from 0.1:99.9 to 95:5.
The above prior art is related to sustained-release formulations (including in a tablet form) which contain various additives, such as polymeric matrix, binders and compression agents in significant amount. However, no free DBNPA compound in a compacted form has been used and/or described in the literature. The ability to provide an almost net content of the active compacted material (such as in a tablet, granule, pellet or briquette form) is most certainly a significant advantage.

The handling of the existing DBNPA powdered solid material requires severe safety precautions due to the hazardous nature of this biocide, especially in a fine powdered form.
An additional problem concerning the application of powdered DBNPA, is the tendency of the powder to agglomerate, creating lumps and a bulky material. This phenomenon reduces the flowability of the product and causes handling and safety problems.

In view of these disadvantages of powdered DBNPA there is a need for a safer, easy to handle and user-friendly densified particulate DBNPA. Such DBNPA should be free of said agglomeration phenomena. As was mentioned above, the densified forms known in the art have the considerable drawback of requiring the addition of binders and fillers to obtain suitable solid forms of the biocide. Therefore, compacted forms known in the art do not provide net or almost net contents of active material in the tablet, granule, briquette or pellet form. It has now been found that it is possible to prepare compacted forms of DBNPA which have sufficient strength and provide a slow release of the active material into the water without losing their compacted nature. It has further been surprisingly found that it is possible to prepare compacted forms of this biocide, without employing any binder or filler.
It is an object of the present invention to provide a compacted DBNPA particle in a granular and/or a tablet and/or a briquette and/or a pellet form. It is a further object of the present invention to provide a compacted DBNPA particle having a diameter larger than 0.5 mm., with no binder, filler or additive added. Yet a further object of the present invention is to provide a compacted DBNPA particle that contains from 0 to about 3 wt % of water content. It is yet another object of the present invention to provide a non-agglomerative DBNPA.

SUMMARY OF THE INVENTION
The present invention provides an essentially pure compacted 2,2-Dibromo-3-nitrilopropionamide (DBNPA) in a granular and/or tablet and/or briquette and/or pellet form. A process for producing the same essentially pure compacted DBNPA is provided, as well.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
A major embodiment of the present invention is to provide a process for obtaining dry-compacted DBNPA in either granular and/or tablet and/or briquette and/or pellet form. It should be pointed out, however, that as it is apparent to a person skilled in the art, the actual shape of the compacted or densified form is not an important parameter, and any obtainable shape is within the scope of the present invention.
The compacted DBNPA particle of the present invention avoids the above mentioned shortcomings of powdered DBNPA and offers a safer material, easy to handle, user friendly and at the same time meets the highly demanding environmental requirements existing for any mode of biocide application. The compacted DBNPA can be used to prepare a liquid formulation with various solvents or to generate a fresh aqueous biocide solution on site.

The application of the compacted DBNPA, according to the present invention has several advantages:
a) Use of a concentrated solid biocide (>95 wt % active material), and the avoidance of an organic solvent which is required as a co-solvent to prepare an aqueous formulation.
b) Simplification of operation and minimization of handling, resulted in less exposure of the user to the harmful biocide.
c) Increased logistic efficiency and minimization of environmental pollution.
According to the invention, it has been found that powdered DBNPA (such as 98 wt % active material) can be compacted in a dry-process, without the addition of a binder, to yield a product in either a tablet and/or a granular and/or a briquette and/or a pellet form.
According to the invention, the process for compacting powdered DBNPA provides high quality tablets at a moderate pressure of 1300 kg/cm2. More specifically, the process is characterized in that DBNPA is compressed with a pressure of at least 500 kg/cm2, to yield a compacted DBNPA pellet or tablet. Preferably, the pressure employed is between about 1000 and 2000 kg/cm2. Thus, for instance, the density obtained under a compaction pressure of 1500 kg/cm2 (2.1 g/cm3) is 88% of the theoretical density of DBNPA.
Preferred compacted biocidal products of the present invention, are those comprising at least 97% (by wt) DBNPA, and between 0 and about 3% (by wt) of water and/or inert ingredient.
The following examples are provided merely to illustrate the invention and are not intended to limit the scope of the invention in any manner.

EXAMPLES
1. Preparation of DBNPA Pellets
Powdered DBNPA was dried and compacted using an hydraulic press, under three different pressure levels: 500, 1000 and 1500 kg/cm2, using a tungsten carbide cylindrical mold 1.8 cm in diameter. The compaction was effected using dry powder and a powder which was humidified by the addition of 2 wt % H2O. The ratio of the cylindrical pellet height/diameter is about 1.
Each pellet was tested to determine its density and Crushing Strength (CS). The density of the compact was determined by measuring its dimensions and weight. CS was measured by standard compression test. Samples that were humidified by the addition of 2 wt % H2O were dried at 105° C. for 2 hours before the density and CS were measured. The results of these tests are shown in Table 1. The CS of compacted DBNPA which still contained 2 wt % H2O was 28, 44 and 70 kg/cm2 for the compaction pressures of 500, 1000 and 1500 kg/cm2 respectively.

2. Process for Tableting Powdered DBNPA (Laboratory Scale)
Powder containing at least 98 wt % 2,2-Dibromo-3-nitrilopropionamide (DBNPA) was weighed into separate portions of about 3 g each, and the portions were tableted individually in a hydraulic press with a single action die. The die had a diameter of 18 mm and the pressure applied was 500 psi equivalent to 1300 kg/cm2. The tablets were sealed in individual polyethylene bags for further measurements.
The tablets were weighed and their thickness measured for calculation of their density. The crushing strength was determined in the diametral mode with a Chatillon Digital Force Gauge (DFG-50), with a maximum force of 25 kg. A total of 40 tablets were measured and the averages of the determinations are given in Table 2.
TABLE 2 Physical Properties of the DBNPA Tablets Weight, g 3.01 ± 0.45 Thickness, mm 5.67 ± 0.86 Density, g/cm3 2.09 ± 0.15 Crushing strength, kg/cm2 10.15 ± 2.74 
The static dissolution rate of the DBNPA tablets was determined to be 0.15 gr/h±0.04, by the “weight loss of solid method.”

3. Process for Tableting Powdered DBNPA (Scaling-Up)
A scale-up of the laboratory tableting process was performed in the equipment of a tableter manufacturer, in which 200 kg of tablets were produced from powder containing at least 98 wt % DBNPA.
The tableting process was performed using a rotary, multi-die tableter, die diameter 14 mm, with automatic feeding system. No problems were observed with filling up to 250-300 tabs/min. Specific compression force 1500 to 2000 kg/cm2.
The DBNPA tablets obtained from the scale-up process were examined and compared to the ones obtained in the laboratory-scale process (Table 3).
TABLE 3 Physical Properties of the DBNPA Tablets Thick- Diam- Crushing Tab- Weight, ness, eter, Density, Strength, lets g mm mm g/cm3 kg/cm2 Scale- 3.05 ± 0.16 9.98 ± 0.11 14.2 1.93 ± 0.09 11.6 ± 3.1 up Lab. 3.00 ± 0.45 5.67 ± 0.86 18 2.09 ± 0.15 10.2 ± 2.8
The tablets produced during the scale-up process had a smaller diameter and a greater thickness than those produced at the laboratory-scale, but the average weight was the same. The density of the tablets from the scale-up was slightly lower, but the crushing strength was 10% higher. The static dissolution rate of the DBNPA tablets was determined to be 0.14±0.03 gr/h, by the “weight loss of solid method”. This result is very similar to the dissolution rate that was measured for the tablets that were prepared in the laboratory (0.15±0.04 gr/h).

4. Process for Granulating Powdered DBNPA (Compaction/Granulation)
Production of granular DBNPA by the compaction/granulation process was performed using a small WP 50 laboratory compactor, with a single 5 mm screen installed in the crushing system. Powder containing at least 98 wt % DBNPA was used. The compaction of the powder to a flake and subsequent crushing to ˜5 mm granules went smoothly, and the material was screened. 11.5 kg of 2-5 mm granules were produced. The feed rate was 110 kg/hr. The DBNPA compacted well, without the aid of a binder, and high quality granules were obtained.
The invention claimed is:
1. A non-agglomerative compacted 2,2-dibromo-3-nitrilopropionamide (DBNPA) in a form selected from the group consisting of granular form, tablets, briquettes, and pellets, free from added binders, additives, and fillers, consisting essentially of
at least 97 wt % of DBNPA and the balance is water and inert ingredients, wherein said compacted DBNPA was compressed in a compactor.
2. The non-agglomerative compacted granular DBNPA, according to claim 1, consisting of granules having a diameter larger than 0.5 mm.
3. The non-agglomerative compacted DBNPA, according to claim 1, providing a release of DBNPA into water without losing the compacted nature.
4. The non-agglomerative compacted DBNPA according to claim 1, comprising at least 98% of DBNPA.
5. The non-agglomerative compacted granular DBNPA according to claim 2, consisting of granules having a diameter of at least 2 mm.
6. The non-agglomerative compacted DBNPA according to claim 1, wherein said DBNPA is in a tablet form which has been compressed with a pressure of at least 500 kg/cm2.
7. A process for producing the non-agglomerative compacted DBNPA of claim 1, including the step of converting powdered DBNPA into said compacted DBNPA without the addition of binders and/or fillers.
8. The process for producing compacted tableted DBNPA, according to claim 7, including the step of converting powdered DBNPA into tableted DBNPA.
9. The process for producing compacted granular DBNPA, according to claim 7, including the step of converting powdered DBNPA into granular DBNPA.
10. The process for producing compacted tableted DBNPA, according to claim 7, characterized in that DBNPA is compressed with a pressure of at least 500 kg/cm2, to yield a compacted DBNPA product.
11. The process according to claim 10, wherein the pressure is between about 1000 and 2000 kg/cm2.

The National Pesticide Information Retrieval System (NPIRS) identifies 16 companies with active labels for products containing the chemical DBNPA. To view the complete list of companies, product names and percent DBNPA in formulated products click the following url and enter the CAS Registry number in the Active Ingredient field.

DBNPA's production and use as a bactericide and algicide in commercial water cooling and treatment systems and paper-pulp mill water systems may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 9X10-4 mm Hg at 25 °C indicates DBNPA will exist solely as a vapor in the ambient atmosphere. Vapor-phase DBNPA will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 8 days. Based on photolysis studies showing degradation in aqueous solution exposed to sunlight (99% loss in 28 days), DBNPA is expected to be susceptible to direct photolysis in the air, water and soil. If released to soil, DBNPA is expected to have high mobility based upon an estimated Koc of 58. Volatilization from moist soil surfaces or water is not expected to be an important fate process based upon an estimated Henry's Law constant of 1.9X10-8 atm-cu m/mole. Degradation in soil and water is expected to occur through both abiotic and biotic processes. Soil half-lives ranged from 4 to 25 hours in 7 different soils with pH values of 4.8 to 7.5. If released into water, DBNPA is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. In both anaerobic and aerobic metabolism studies, half-lives of less than 4 hours were measured for DBNPA; loss was due to both hydrolysis and biodegradation. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis half-lives of 67 days, 63 hours, and 73 minutes were measured for DBNPA at pH 5, 7, and 9, respectively. Occupational exposure to DBNPA may occur through inhalation and dermal contact with this compound at workplaces where DBNPA is produced or used. The general population may be exposed to DBNPA via dermal contact with consumer products such as latex paint containing DBNPA.

DBNPA's production and use as a bactericide and algicide in commercial water cooling and treatment systems and paper-pulp mill water systems(1) may result in its release to the environment through various waste streams(SRC).
Based on a classification scheme(1), an estimated Koc value of 58(SRC), determined from a log Kow of 0.80(2) and a regression-derived equation(3), indicates that DBNPA is expected to have high mobility in soil(SRC). Volatilization of DBNPA from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.9X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 9.0X10-4 mm Hg(2), and water solubility, 1.5X10+4 mg/L(2). DBNPA is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Biodegradation in soil may be an important environmental fate process; however, degradation in soil is expected to be due to both abiotic and biotic processes(2,4). DBNPA is susceptible to aqueous hydrolysis in moist soils and susceptible to photodegradation when exposed to sunlight(2,4). Half-lives ranged from 4 to 25 hours in 7 different soils with pH values of 4.8 to 7.5(4).

Based on a classification scheme(1), an estimated Koc value of 58(SRC), determined from a log Kow of 0.80(2) and a regression-derived equation(3), indicates that DBNPA is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 1.9X10-8 atm-cu m/mole(SRC), determined from its vapor pressure, 9.0X10-4 mm Hg(2) and water solubility, 1.5X10+4 mg/L(2). According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Degradation in water is due to both abiotic and biotic processes(2,6). Hydrolysis half-lives of 67 days, 63 hours, and 73 minutes were measured for DBNPA at pH 5, 7, and 9, respectively(2). Dibromoacetic acid is the major degradate at pH 5 while dibromoacetonitrile is the major degradate at pH values of 7 and 9(2). The half-life of DBNPA is less than 4 hours in anaerobic and aerobic metabolism studies(2). Degradates include oxalic acid, 2-cyanoacetamide, bromoacetamide, dibromoacetic acid, bromoacetic acid, and dibromoacetonitrile; the concentration of each degradate over time varies with the oxygen condition(2). DBNPA is susceptible to photodegradation in water(6); <1% of initial DBNPA remained after exposure to sunlight for 28 days(6). Sunlight degrades DBNPA in water at rates that become relatively fast compared to hydrolysis at pH less than 5(6).

According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), DBNPA, which has a vapor pressure of 9X10-4 mm Hg at 25 °C(2), will exist solely as a vapor in the ambient atmosphere. Vapor-phase DBNPA 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 8 days(SRC), calculated from its rate constant of 2.0X10-12 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Based on photolysis studies showing degradation in aqueous solution exposed to sunlight (99% loss in 28 days)(4), DBNPA is expected to be susceptible to direct photolysis in the atmosphere(SRC).
The disappearance of DBNPA at 50 ppm in soil was more rapid than when present in an aqueous solution at a similar pH(1). Degradation in 7 soils was measured; half-lives of 4, 12, 15, 15, 6, 25, and 15 hours were reported for a sandy loam (pH 7.5), loam (pH 4.8), silty loam (pH 5.8), sandy loam (pH 6.5), loamy sand (pH 5.8), silty clay loam (pH 5.1), and loam (pH 4.8) soil, respectively(1). DBNPA has a half-life of less than 4 hours in an aerobic aquatic metabolism study(2). Dibromoacetic acid (reached 66% of applied at 0 hour, 9% at hour 5) and 2-cyanoacetamide (reached 56.5% of applied at hour 5, 2.3% at day 30) were the major degradates(2). Other degradates include oxalic acid, bromoacetic acid, bromoacetamide, and dibromoacetonitrile(2). Oxalic acid, 2-cyanoacetamide (16% by day 2) and bromoacetamide (2% by day 2) were found in the sediment layer(2). DBNPA, present at 100 mg/L, reached 0% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L in the Japanese MITI test classifying the compound as not readily biodegradable(3). Microbial degradation of DBNPA has been demonstrated by the use of tracer techniques (14C-radio-labeled) which yielded 40% 14-CO2 after two weeks in the presence of waste treatment sludge(1).

2,2-Dibromo-3-nitilopropionamide has a half-life of less than 4 hours in an anaerobic aquatic metabolism study; residues were mainly found in the aqueous layer. Concentrations of the two main degradates 2-cyanoacetamide (reached 56% of applied within 7 days) and dibromoacetic acid (reached 27% of applied at 0 hr, 17% by day 48) were measured. Other minor degradates include oxalic acid, bromoacetamide and dibromoactonitrile. 2-Cyanoacetamide, dibromoacetonitrile and bromoacetamide were found in the sediment layer. The anaerobic metabolism study includes degradation due to both biotic and abiotic mechanisms(1).
The rate constant for the vapor-phase reaction of DBNPA with photochemically-produced hydroxyl radicals has been estimated as 2.0X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 8 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Less than 1% of a 4000 ppm aqueous solution of DBNPA remained after 28 days exposure to sunlight(2); 91% of the added DBNPA was still present in the dark control after the same period of time(2). Dibromoacetic acid (63.7%) is the major degradate at pH 5 (half-life of 14.8 hours; dark control forms dibromoacetic acid at 38.6%) and at pH 7 (half-life of 6.9 hours; dark control forms dibromoacetic acid at 74.9%) in aqueous photolysis studies(2). Hydrolysis half-lives of 155, 8.8, 5.8, 2.0, and 0.34 hours were measured at pH values of 6.0, 7.3, 7.7, 8.0, and 8.9, respectively(2). The half-life of DBNPA is 67 days at pH 5, 63 hours at pH 7, and 73 minutes at pH 9(3). Dibromoacetic acid (30.6% of applied), dibromoacetonitrile (54.5% of applied), and dibromoacetonitrile (38.6% of applied) are the major degradates at pH values of 5, 7, and 9, respectively(3).

The Koc of DBNPA is estimated as 58(SRC), using a log Kow of 0.80(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that DBNPA is expected to have high mobility in soil.
An estimated BCF of 3 was calculated in fish for DBNPA(SRC), using a log Kow of 0.80(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC). Using carp (Cyprinus carpio) which were exposed over an 8-week period, DBNPA was reported to have low bioconcentration (BCF value not available)(4).
The Henry's Law constant for DBNPA is estimated as 1.9X10-8 atm-cu m/mole(SRC) derived from its vapor pressure, 9.0X10-4 mm Hg(1), and water solubility, 1.5X10+4 mg/L(1). This Henry's Law constant indicates that DBNPA is expected to be essentially nonvolatile from water surfaces(2). DBNPA's estimated Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to occur(SRC). DBNPA is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).
NIOSH (NOES Survey 1981-1983) has statistically estimated that 9,829 workers (108 of these were female) were potentially exposed to DBNPA in the US(1). Occupational exposure to DBNPA may occur through inhalation and dermal contact with this compound at workplaces where DBNPA is produced or used(SRC). The general population may be exposed to DBNPA via dermal contact with consumer products such as latex paint containing DBNPA(SRC).