Improved Respirator Carbons for Ammonia Hazards

改进呼吸器碳以应对氨危害

• 批准号: 9139745
• 负责人: GIRISH SRINIVAS
• 金额: $ 15万
• 依托单位: TDA RESEARCH, INC.
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2017-09-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9139745
• 关键词: Improved; Respirator; Carbons; Ammonia; Hazards

 DESCRIPTION (provided by applicant): TDA Research, Inc. (TDA), proposes to develop new types of activated carbons to protect the more than 700,000 agricultural workers, who according to the CDC are at risk from exposure to toxic levels of ammonia. In addition to agricultural workers, fire fighters, first responders and chemical industry personal are also at risk. OSHA rates 300 ppmv NH3 in air as Immediately Dangerous to Life and Health (IDLH). Levels of 150 ppmv have led to permanent scarring of lung tissue causing chronic respiratory illness. Ammonia readily dissolves in water and damages moist tissues of the body, and especially the eyes. Initial eye-tissue damage and necrosis caused by ammonia is often followed by conjunctivitis and secondary eye infection. Chronic exposure to even 6 ppmv has caused eye damage and temporary blindness, and high levels have caused permanent blindness. In poorly-ventilated buildings of the over 257,000 Animal Feeding Operations (AFO) and the over 15,500 Concentrated Animal Feeding Operations (CAFO), for example, NH3 levels routinely exceed 50 ppmv, and with low winter-ventilation rates, agricultural workers are often exposed to 100-200 ppmv. Advocates of public health are recommending that children down-wind of ammonia-releasing operations should not be exposed to more than 300 ppbv NH3 in air. Hitherto, workers have relied on respirators incorporating activated carbons produced from pyrolysis of coconut shell-a technology developed for World War I gas masks. However, the best of these has recently been discontinued, leaving manufacturers of ammonia respirators scrambling and with a critical need for new supplies of activated carbons that are specific for use in ammonia respirators. Most off-the-shelf activated carbons, designed for other purposes, are ineffective for NH3 uptake. Staff at TDA has over 20 years of experience in the design of specialty sorbents, supplying over 100 metric tons per year to customers, worldwide. In preliminary studies, TDA has demonstrated that a treated activated carbon performs significantly better for NH3 uptake compared to activated carbons now currently available. In Phase I, the carbons will be optimized for NH3 uptake. In Phase II, carbons will be scaled up for commercialization.

 描述（由申请人提供）：TDA Research, Inc. (TDA) 提议开发新型活性炭来保护超过 700,000 名农业工人，据 CDC 称，这些工人面临暴露于有毒水平的氨的风险。除了农业工人之外，消防员、急救人员和化学工业人员也面临风险。 OSHA 将空气中 300 ppmv NH3 列为对生命和健康立即危险 (IDLH)。 150 ppmv 的浓度会导致肺组织永久性疤痕，从而导致慢性呼吸道疾病。氨很容易溶解在水中并损害身体的潮湿组织，尤其是眼睛。氨引起的最初眼组织损伤和坏死通常会导致结膜炎和继发性眼部感染。长期接触即使是 6 ppmv 也会导致眼睛损伤和暂时失明，高浓度则会导致永久性失明。例如，在超过 257,000 个动物饲养场 (AFO) 和超过 15,500 个动物集中饲养场 (CAFO) 的通风不良的建筑物中，NH3 水平通常超过 50 ppmv，并且由于冬季通风率较低，农业工人经常暴露在 100-200 ppmv 的环境中。公共卫生倡导者建议，氨释放作业的下风向儿童不应接触空气中浓度超过 300 ppbv 的 NH3。迄今为止，工人们一直依赖含有椰子壳热解活性炭的呼吸器，这是为第一次世界大战防毒面具开发的技术。然而，其中最好的产品最近已停产，使得氨呼吸器制造商陷入困境，迫切需要专门用于氨呼吸器的新活性炭供应。大多数专为其他目的而设计的现成活性炭对于 NH3 吸收。 TDA 的员工在特种吸附剂设计方面拥有 20 多年的经验，每年向全球客户供应超过 100 吨的吸附剂。在初步研究中，TDA 已证明，与现有的活性炭相比，经过处理的活性炭在 NH3 吸收方面的性能明显更好。在第一阶段，碳将针对 NH3 吸收进行优化。在第二阶段，碳将扩大规模以实现商业化。