棉尘为什么有一部单独的法规

Why cotton dust has its own standard

1978 年 OSHA 颁布了 29 CFR 1910.1043 棉尘标准，最近一次更新在 2024 年。立法依据是棉尘暴露会导致棉尘病（byssinosis，俗称褐肺病）这一慢性呼吸系统疾病，并可能诱发或加重慢性支气管炎、哮喘、肺气肿等病症。法规对棉尘的定义相当宽：处理或加工棉花过程中空气中存在的粉尘，可能混合植物碎屑、纤维、细菌、真菌、土壤、农药以及生长、收获、后续加工或储存过程中积累的其他污染物；从原棉到织造或针织成布的全过程粉尘，以及使用原棉、废棉纤维或纺织厂棉纤维副产品的其他工序产生的粉尘，都算棉尘。织造工序中的润滑油雾则不计入。

OSHA promulgated 29 CFR 1910.1043, the cotton dust standard, in 1978, with its most recent update in 2024. The basis was OSHA's finding that cotton dust exposure causes byssinosis, or brown lung, a chronic respiratory disease, and can produce or aggravate chronic bronchitis, asthma and emphysema. The definition is broad: dust present in air during the handling or processing of cotton, which may contain ground-up plant matter, fibre, bacteria, fungi, soil, pesticides and other contaminants accumulated during growing, harvesting, processing or storage. Dust from any operation using raw or waste cotton fibres or cotton fibre by-products from textile mills counts as cotton dust. Lubricating oil mist associated with weaving does not.

限值分三档，行动水平是限值的一半

Three PEL tiers, with action levels at half

1910.1043(c) 按工序划分了三档 8 小时时间加权平均许可暴露限值（PEL），均以垂直淘析器或等效仪器测得的「无绒可吸入棉尘」为准：纺纱与洗棉作业 200 µg/m³；纺织厂废料房作业，或纺纱过程中接触所谓低等级洗涤棉产生的粉尘 500 µg/m³；浆纱与织造工序 750 µg/m³。对应的行动水平（action level）分别为 100、250 与 375 µg/m³，即各自 PEL 的一半，达到行动水平即触发监测与医学监护义务。适用范围也有边界：该标准不适用于针织、分级或仓储作业（NIOSH 研究性抽样除外），也不适用于棉花收获与轧花或建筑业；棉籽加工与废料加工场所只适用医学监护与病历记录相关条款。

1910.1043(c) sets three eight-hour time weighted average permissible exposure limits for lint-free respirable cotton dust, measured by vertical elutriator or equivalent: 200 micrograms per cubic metre for yarn manufacturing and cotton washing, 500 for textile mill waste house operations or exposure in yarn manufacturing to dust from lower grade washed cotton, and 750 for slashing and weaving. The corresponding action levels are 100, 250 and 375 micrograms per cubic metre, each half the PEL, and reaching an action level triggers monitoring and medical surveillance duties. Scope has edges too: the standard does not apply to knitting, classing or warehousing (except for NIOSH study access), nor to cotton harvesting, ginning or construction, and only the medical surveillance and record provisions apply to cottonseed and waste processing operations.

测什么、怎么测：15 微米与垂直淘析器

What is measured: 15 microns and the vertical elutriator

法规管的不是全部飘浮物，而是「无绒可吸入棉尘」，定义为空气动力学等效直径约 15 微米及以下的棉尘颗粒。标准采样设备是垂直淘析器棉尘采样器，其粒径切割点在 7.4 ±0.2 升/分钟流量下约为 15 微米。若使用替代仪器，企业必须通过 OSHA 意见函或自行举证建立等效性：需在同一范围内采集可吸入颗粒物，进行现场与实验室的并行对比，且在 0.5 至 2 倍 PEL 范围内至少采集 100 个样本，其中 90% 的样本读数与垂直淘析器读数偏差在正负 25% 以内、置信水平 95%。这条对采购在线粉尘监测设备的工厂尤其重要——仪器好用不等于可用于合规举证。

The rule targets lint-free respirable cotton dust, defined as particles of approximately 15 micrometres or less aerodynamic equivalent diameter. The reference sampler is the vertical elutriator, whose cut-off is approximately 15 micrometres at a flow rate of 7.4 plus or minus 0.2 litres per minute. Any alternative instrument requires equivalency established through an OSHA opinion or employer documentation: it must collect respirable particulate in the same range, equivalency data must come from side-by-side field and laboratory comparisons, and at least 100 samples across 0.5 to 2 times the PEL must be collected with 90 percent of them within plus or minus 25 percent of the elutriator reading at 95 percent confidence. Mills buying continuous dust monitors should note that a useful instrument is not automatically a compliant one.

压缩空气吹扫为什么被明文禁止

Why compressed air blow-down is prohibited

这是 1910.1043 里对清洁作业最直接、也最常被违反的一条。法规 (g) 工作实践部分要求所有雇主，无论员工暴露水平如何，都必须立即建立并实施书面的工作实践计划以最小化棉尘暴露，其中明确：在可行替代方式存在时，禁止使用压缩空气进行整间或局部的「吹扫」（blow down）清洁；确需使用压缩空气清洁时，执行吹扫或吹除作业的员工必须佩戴合适的呼吸防护，非必要人员必须在作业期间离开受影响区域。更绝对的一条是：禁止用压缩空气清洁工作服或地面——这一条没有「可行性」豁免。原因显而易见，气枪把已经沉降的棉尘重新扬起，把一个可控的表面问题变成了全车间的呼吸暴露问题。

This is the clause most directly aimed at cleaning practice, and the most frequently breached. Paragraph (g) requires every employer, regardless of exposure level, to immediately establish and implement a written work practice programme minimising cotton dust exposure. Within it, compressed air blow-down cleaning is prohibited where alternative means are feasible; where compressed air is used, employees performing the blow-down or blow-off must wear suitable respirators and non-essential employees must leave the affected area. One clause is absolute: cleaning of clothing or floors with compressed air is prohibited, with no feasibility exemption. The logic is obvious — an air gun re-entrains settled dust and converts a contained surface problem into a plant-wide inhalation exposure.

地面清扫必须用吸尘：法规原文的措辞

Floors must be vacuumed, in the regulator's own words

紧接着的条款写得同样明确：地面清扫应使用吸尘方式，或采用其他专为最小化粉尘扩散而设计的方法。这意味着扫帚干扫在棉尘车间同样不是合规选项，除非能证明该方法确实最小化了粉尘扩散。此外，在员工暴露浓度超过 PEL 的区域，棉花与废棉的堆放、分拣、打包、倾倒、清运等处理必须采用机械方式，除非雇主能证明机械化不可行；不可行时也必须采用能把暴露降到最低可行水平的方法。把这几条串起来看，法规给清洁作业划定的路线非常清楚：源头封闭与局部排风优先，地面靠吸尘，压缩空气基本出局。

The next clause is equally direct: floor sweeping shall be performed with a vacuum, or with methods designed to minimise dispersal of dust. Dry broom sweeping is therefore not a compliant default in a cotton dust area unless it can be shown to minimise dispersal. In addition, where employees are exposed above the PEL, cotton and cotton waste must be stacked, sorted, baled, dumped, removed or otherwise handled by mechanical means unless the employer can show that is infeasible, in which case the method must reduce exposure to the lowest feasible level. Read together, the regulatory route for housekeeping is clear: source enclosure and local exhaust first, vacuum for floors, compressed air essentially out.

飞花的第二重风险：火灾与设备磨损

The second risk of lint: fire and mechanical wear

棉尘不只是职业健康问题。保险机构 AXA XL 的棉纺厂飞花控制指引指出，飞花堆积会堵塞轴承、导纱钩、钢丝圈、纱管、罗拉等运动部件和润滑部位，甚至附着在旋转件上造成动不平衡，进而摩擦生热引发着火；飞花还会在成品中形成被称为 motes 的小颗粒影响品质。火灾角度更值得警惕：飞花是理想的燃料与火焰蔓延通道，散落的飞花燃烧速度近乎爆燃，燃烧中的飞花会随气流悬浮飘移，把局部火点迅速扩散成全车间火灾。这也是为什么飞花收集箱必须按需及时清空并转移到安全地点，绝不能让大量飞花在生产区的敞口料箱中堆积。

Cotton dust is not only an occupational health issue. AXA XL's lint control guidance for cotton mills notes that accumulating lint clogs bearings, guide wires, travellers, bobbins, rolls and other moving or lubricated parts, and can build up on rotating parts causing imbalance, friction and ignition. Lint also produces motes in finished product. The fire angle deserves more attention: lint is ideal fuel and a path for a hot, fast-spreading fire, loose lint burns with almost explosive rapidity, and burning lint floats suspended in air currents, spreading a local ignition across a mill. That is why lint collection boxes must be emptied as needed into containers placed in a safe location, and why large quantities of lint must never accumulate in open tote boxes in production areas.

除尘管道与电气：可直接照抄的工程要求

Ductwork and electrical requirements you can copy

同一份指引对集中式飞花收集系统给出了具体的工程要求，可作为改造依据：使用金属不燃风管；不得让风管穿越无喷淋保护的可燃结构区域（例如许多老厂房木地板下的空间）；风管应每约 25 英尺（8 米）设置一个检查清扫门以便清除积存的细飞花；穿越楼板的风管周围应设置坚固的不燃防水套环；风管不应穿越防火墙，无法避免时须加装经认证的自动防火阀，且阀体设计不得积存飞花堵塞管道。消防保护上，宽度超过 24 英寸（0.6 米）的风管内部应设置喷淋；小于 24 英寸的风管应在墙体穿越处设置火花抑制系统，并与探测系统联锁在动作时停机收集风机；宽度超过 48 英寸（1.2 米）的风管下方应设置喷淋。粉尘房内的电气设备应按 Class III Division 1 选型，使用矿物绝缘电缆或穿螺纹导管敷线，接头与接线盒须防尘密封，灯具应带垫圈厚玻璃罩与外部金属护罩。

The same guidance gives concrete engineering requirements for central lint collection. Use metallic, non-combustible ductwork. Do not run ducts through unsprinklered areas of combustible construction, such as spaces under wood floors in older mills. Provide inspection and clean-out doors spaced about 25 feet (8 metres) apart so fines can be removed. Surround ducts passing through floors with substantial non-combustible watertight collars. Do not install ducts through fire walls; where unavoidable, fit listed automatic fire dampers designed so they will not collect waste lint and obstruct the duct. For protection, install sprinklers inside all ducts over 24 inches (0.6 metres) wide, provide spark suppression at wall penetrations inside ducts less than 24 inches wide with interlocks to shut down the collection fan, and install sprinklers under all ducts over 48 inches (1.2 metres) wide. In the dust room, install only Class III Division 1 electrical equipment, using MI cable or threaded conduit, with dust-tight fittings and boxes, and fixtures with gasketed heavy glass globes and outside metal guards.

分区清洁频次与吸尘设备选型

Zone frequencies and vacuum selection

落地做法建议按工序分区制定频次，并按粉尘负荷选设备。开清棉、梳棉这类原棉杂质与飞花最重的工段，班中就需要局部清理，宜配大风量、大容量的移动式工业吸尘器；细纱、络筒等区域可按班次清理；织造区侧重浆料残渣与经纱飞花，需兼顾机台缝隙清洁。设备匹配上，永乐 X7-5 中央吸尘器为 380V、7.5KW、530m³/h、整机 115kg，适合大型车间多工位集中管路，把远端工位一并纳入；永乐 X1-8 采用 80L 大桶、天能 12V/100AH×2 电瓶、1.15KW、350m³/h、整机 62kg，无电源线束缚，适合大跨度厂房机动清扫；小型车间或单机位保养可选永乐 63，0.75KW、30L 桶、380V/220V 双电压、28kg，轻便且不必上大功率。选型时务必关注过滤级配与滤芯有效面积——棉絮极易在滤芯表面结饼，滤面不足会让吸力在半班内明显衰减。

In practice, set cleaning frequency by process zone and size equipment to dust load. Opening and carding, where trash and lint are heaviest, need in-shift attention and suit high-airflow, large-capacity mobile industrial vacuums. Ring spinning and winding can usually be handled per shift. Weaving focuses on sizing residue and warp lint, with attention to machine crevices. On equipment, the Yongle X7-5 central vacuum runs 380V, 7.5 kW, 530 cubic metres per hour at 115 kg, suited to piped multi-station coverage in large mills including remote positions. The Yongle X1-8 uses an 80 L bin, two 12V/100Ah batteries, 1.15 kW and 350 cubic metres per hour at 62 kg, cordless for long-span buildings. For small mills or single-machine maintenance, the Yongle 63 offers 0.75 kW, a 30 L drum, dual 380V/220V and 28 kg. Pay close attention to filter staging and effective filter area — cotton fly cakes readily on filter surfaces, and an undersized filter loses suction noticeably within half a shift.