两个数字决定一切：PEL 50 与行动水平 25 µg/m³

Two Numbers Drive Everything: PEL 50 and Action Level 25 µg/m³

美国建筑业可呼吸性结晶硅（respirable crystalline silica）的容许暴露限值 PEL 是 50 µg/m³（8 小时时间加权平均），行动水平 AL 是 25 µg/m³。这两个数字触发标准里几乎全部义务：达到或超过 PEL 要求工程控制、书面暴露控制计划、清扫规定与个人防护；每年有 30 天以上达到或超过 AL 且需佩戴呼吸器的工人，必须提供医学监护。OSHA 在 2016 年把建筑业 PEL 从沿用自 1971 年的 250 µg/m³ 直接砍到 50 µg/m³，降幅 80%。参照 NIOSH 的现场测量，无控制的干式切割混凝土可以把暴露推到 1,000 µg/m³ 以上，也就是 PEL 的 20 倍——这不是四舍五入的差距，是数量级的差距。

In US construction, the permissible exposure limit for respirable crystalline silica is 50 µg/m³ as an 8-hour time-weighted average, and the action level is 25 µg/m³. These two numbers trigger nearly every obligation in the standard: engineering controls, a written exposure control plan, housekeeping rules and respiratory protection. Workers who wear a respirator 30 or more days per year must be offered medical surveillance. OSHA cut the construction PEL from 250 µg/m³, a limit inherited from a 1971 threshold limit value, down to 50 µg/m³ in 2016, an 80 percent reduction. NIOSH field data shows uncontrolled dry cutting of concrete can exceed 1,000 µg/m³, twenty times the PEL. That is not a rounding error, it is an order of magnitude.

Table 1 是什么：照做就免于空气监测

What Table 1 Is: Follow It and Skip Air Monitoring

29 CFR 1926.1153 Table 1 列出了 18 类常见作业（固定式石材锯、手持切割锯、手持及台式钻、勾缝磨光机、破碎镐、手扶式铣刨与地面研磨机、驾驶式铣刨机、破碎机、重型设备等），每一类都写明了必须采用的工程控制、以及 4 小时以内/超过 4 小时两档的呼吸器指定防护系数（APF）。只要完整实施 Table 1 对应的控制措施，雇主可以推定合规，无需做工人暴露空气采样。反过来，只要某项作业在 Table 1 中列出但你没有完整照做，就必须自己做暴露评估并用实测数据证明低于 PEL——成本远高于直接买对设备。

Table 1 of 29 CFR 1926.1153 lists eighteen common tasks, from stationary masonry saws and handheld power saws to handheld drills, tuckpointing grinders, jackhammers, walk-behind milling machines and floor grinders, drivable milling machines, crushing machines and heavy equipment. For each task it specifies the required engineering control plus the assigned protection factor of any respirator for two duration bands, four hours or less and more than four hours. If you fully implement the listed controls, compliance is presumed and no exposure air sampling is required. Skip any part of it for a listed task and you must assess exposure yourself and prove with measured data that you stay below the PEL, which costs far more than buying the right equipment.

写死的硬指标：25 CFM 每英寸磨盘直径

The One Hard Number: 25 CFM per Inch of Wheel Diameter

Table 1 里唯一给出明确风量数字的是手持磨光机。第 (xi) 项勾缝（tuckpointing，即砂浆勾缝清除）和第 (xii) 项其他用途手持磨光机都要求：使用市售专用防尘罩加除尘系统，且除尘器必须提供每英寸磨盘直径不低于 25 CFM 的风量，配备效率不低于 99% 的滤芯，并具备旋风预分离器或滤芯清灰机构。换算一下：5 英寸磨盘至少 125 CFM，7 英寸磨盘至少 175 CFM，9 英寸磨盘至少 225 CFM。选型时要看的是带管带罩后的实际工作风量，不是样本上的最大空载风量——软管越长、越细，罩口负压损失越大。

Handheld grinders are the only Table 1 entries with an explicit airflow figure. Entry (xi) for mortar removal, that is tuckpointing, and entry (xii) for grinders used for other purposes both require a commercially available shroud with a dust collection system, and the dust collector must provide 25 cubic feet per minute or greater of airflow per inch of wheel diameter, have a filter with 99 percent or greater efficiency, and include a cyclonic pre-separator or a filter-cleaning mechanism. In practice that means at least 125 CFM for a 5 inch wheel, 175 CFM for a 7 inch wheel and 225 CFM for a 9 inch wheel. Specify the airflow measured through the actual hose and shroud, not the free-air maximum printed on a brochure, because longer and narrower hoses cost you significant suction at the shroud.

其余作业看“厂家推荐风量 + 99% 滤芯 + 清灰机构”

Other Tasks: Manufacturer Airflow, 99% Filter, Filter-Cleaning Mechanism

对于第 (vii) 项手持及台式钻（含冲击钻、电锤）、第 (x) 项破碎镐与手持凿击工具、第 (xiii) 项手扶式铣刨与地面研磨机，Table 1 不给绝对 CFM，而是要求除尘器达到或超过工具制造商推荐的风量，且滤芯效率不低于 99%、带滤芯清灰机构。这条“清灰机构”常被忽略：干式硅尘极细，滤芯几分钟就会糊住导致风量塌陷，没有反吹或震打机构的桶式吸尘器在实际作业 20 分钟后往往已经达不到合规风量。带脉冲反吹的工业吸尘器（如 YLBC110 重工型脉冲反吹工业吸尘器）就是为这种连续高粉尘负荷设计的。

For entry (vii) handheld and stand-mounted drills including impact and rotary hammer drills, entry (x) jackhammers and handheld powered chipping tools, and entry (xiii) walk-behind milling machines and floor grinders, Table 1 does not give an absolute CFM. Instead the dust collector must provide the airflow recommended by the tool manufacturer or greater, have a filter with 99 percent or greater efficiency, and have a filter-cleaning mechanism. That last requirement is routinely ignored. Dry silica dust is extremely fine and blinds a filter within minutes, so a plain drum vacuum without reverse-pulse or shaker cleaning often falls below compliant airflow after twenty minutes of real work. A heavy-duty industrial vacuum with pulse jet filter cleaning, such as the YLBC110 pulse reverse-jet industrial vacuum, is built for exactly this continuous high dust load.

澄清一个高频误解：99% 滤芯 ≠ HEPA，但两处必须 HEPA

Clearing Up a Common Myth: 99% Filter Is Not HEPA, But Three Places Demand HEPA

Table 1 对磨光机、钻孔、破碎的除尘器写的是“99% 或更高效率的滤芯”，而 HEPA 的定义是对 0.3 µm 颗粒捕集效率 99.97%——两者不是一回事，Table 1 并没有在所有作业上强制 HEPA。但有三处明确点名 HEPA：一是钻孔后清理孔内粉尘必须用 HEPA 过滤吸尘器（禁止压缩空气吹）；二是第 (xiii) 项手扶式铣刨/地面研磨机在室内或封闭区域作业时，两遍之间要用 HEPA 过滤吸尘器清除松散积尘；三是清扫环节（见下节）。工程上更稳妥的做法是直接按 HEPA 整机配置，既满足 99% 条款也满足点名 HEPA 的场景，避免现场判定争议。

For grinders, drills and chipping tools Table 1 specifies a filter with 99 percent or greater efficiency. HEPA is defined as 99.97 percent capture at 0.3 microns, so the two are not the same and Table 1 does not mandate HEPA for every task. Three places do name HEPA explicitly. First, a HEPA-filtered vacuum must be used to clean drilled holes, and compressed air blowing is not acceptable. Second, entry (xiii) requires a HEPA-filtered vacuum to remove loose dust between passes when walk-behind milling machines or floor grinders are used indoors or in an enclosed area. Third, housekeeping, covered below. Engineering-wise the safer route is to standardise on HEPA-rated machines so you satisfy both the 99 percent clause and every HEPA-specific scenario without arguing with an inspector on site.

清扫条款：干扫和压缩空气基本被封死

Housekeeping: Dry Sweeping and Compressed Air Are Effectively Closed Off

标准的清扫（housekeeping）条款规定：凡是可能造成工人暴露的场合，不得采用干扫或干刷，除非湿式清扫、HEPA 过滤吸尘等替代方法不可行；不得用压缩空气吹扫衣物或表面，除非同时配备能捕集扬尘的通风系统，或确实没有其他可行方法。这意味着施工现场的扫帚和吹风机在硅尘区域基本退出——收尾清扫要么湿法，要么上 HEPA 吸尘器，大面积落尘可以配手推式扫地机（如 YLBA002 手推式扫地机）做粗清后再用工业吸尘器精清。注意扫地机本身要能做到低扬尘，滤网糊了就等于把粉尘从地面搬到了呼吸带。

The housekeeping provision prohibits dry sweeping or dry brushing where it could contribute to employee exposure, unless wet sweeping, HEPA-filtered vacuuming or other methods that minimise exposure are not feasible. It also prohibits using compressed air to clean clothing or surfaces unless the air is used together with a ventilation system that effectively captures the dust cloud, or no alternative method is available. In practice brooms and blowers are out of the silica zone. Final cleanup is either wet or HEPA vacuumed, and for large areas of settled dust a walk-behind sweeper such as the YLBA002 manual push sweeper can handle the coarse pass before an industrial vacuum does the fine pass. Make sure the sweeper itself is low emission, because a blinded sweeper filter simply moves dust from the floor into the breathing zone.

封闭驾驶室与整机泄漏：两个容易翻车的细节

Enclosed Cabs and Whole-Machine Leakage: Two Easy Ways to Fail

第一，凡是用封闭驾驶室或操作舱作为控制手段的（如驾驶式铣刨机、重型设备），标准要求驾驶室保持尽可能无积尘、门封与关闭机构完好、垫片密封良好、通过持续送新风维持正压，进气必须经过在 0.3–10.0 µm 区间效率 95% 的滤材（相当于 MERV-16 或更好），并具备制冷制热能力。第二，滤芯等级只是第一道关，整机不得有旁通泄漏——桶盖密封条老化、软管接头松脱、排风口未做二级过滤，都会让 HEPA 滤芯形同虚设。验收时应做整机泄漏检查，而不是只看滤芯出厂证书。

First, wherever an enclosed cab or booth is the control, the standard requires it to be kept as free as practicable from settled dust, to have properly working door seals and closing mechanisms, gaskets and seals in good condition, positive pressure maintained by continuous fresh air delivery, intake air filtered through media that is 95 percent efficient in the 0.3 to 10.0 micron range, equivalent to MERV-16 or better, and heating and cooling capability. Second, filter rating is only the first gate. The machine must also have no bypass leakage. A perished lid gasket, a loose hose cuff or an unfiltered exhaust port will defeat a HEPA cartridge completely. Acceptance testing should include a whole-machine leak check, not just a filter certificate from the factory.

罚款不是抽象风险：2026 年的处罚区间

Penalties Are Not an Abstract Risk: The 2026 Numbers

据行业机构援引 OSHA 2025 年 1 月处罚备忘录整理的 2026 年处罚结构：严重违规每项最高约 16,550 美元，故意或重复违规每项最高约 165,514 美元，逾期未整改按每天最高 16,550 美元计。硅尘检查的特点是“成串开单”——查到干切一项，往往连带开出暴露控制措施、书面计划、指定合格人员、医学监护、培训五张罚单。相比之下，把除尘设备一次配对（正确的风量 + 99%/HEPA 滤芯 + 清灰机构 + 无泄漏整机）的采购成本，通常只相当于一张严重违规罚单。

Industry sources citing the OSHA penalty memorandum of January 2025 put the 2026 structure at up to about 16,550 US dollars per serious violation, up to about 165,514 US dollars per wilful or repeat violation, and up to 16,550 US dollars per day for failure to abate. Silica inspections are typically written in bundles: catch a crew dry cutting and the citation package usually also covers the exposure control method, the written plan, the competent person requirement, medical surveillance and training. Set against that, the cost of specifying dust extraction correctly once, meaning the right airflow, a 99 percent or HEPA filter, a filter-cleaning mechanism and a leak-free machine, is usually about the price of a single serious citation.