Hexavalent Chromium and Isocyanate Exposures during Military

Overview

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Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

• 57 ppm and 63 ppm, respectively. All 12 Cr(VI) 8-hr time-weighted averages exceeded the
• 5 µg/m3, and 7 out of 12 exceeded the threshold limit value of 10 µg/m3, with means 38 µg/m3 for
• Health and Safety Executive workplace exposure limit of 20 µg/m3, with means 50.9 µg/m3 for
• velocity in the booth cross-section of 100 fpm (0.508 m/s), from Table G-10, Minimum
• the airflow is reduced to 25% of the full-flow condition used for painting.
• As shown in Table II, the supply rate of 94.4 m3/s (200,000 cfm) produced a velocity of
• across the filter (Table II). Before primer spraying, the exhaust velocity ranged from 0.955
• m/s (188 fpm) to 1.61 m/s (316 fpm), whereas the range expanded to (0.422 (83), 1.81
• this task of 57 ppm and 63 ppm, respectively. One of six samples exceeded the MEK short-
• term exposure limit (STEL: ACGIH = 300 ppm, NIOSH = 300 ppm), and two of six
• exceeded the MIBK STEL (ACGIH = 75 ppm, NIOSH = 75 ppm). One of the six personal
• than 50% breakthrough of MEK on this sample. While these values were retained in the
• classification for the remainder of the day, the MEK and MIBK 8-hr TWAs were 3.4 ppm
• and 3.7 ppm, respectively. The 8-hr TWAs were essentially the same for the hosemen, since
• summarized in Table VI. While measureable levels of 1,2,4-trimethylbenzene, 1,3,5-
• the levels were well below the OEL of 25 ppm. Mean PBZ sample results for EGBE, MEK,
• EGBE 8-hr TWAs were 0.19 ppm and 0.025 ppm for sprayers and hosemen— below the
• OELs (REL = 5 ppm, PEL = 50 ppm) — and only during primer painting were
• Table IV shows that sprayers’ and hosemen’s 8-hr TWAs for TPM were all below the OELs
• (TLV = 10 mg/m3, PEL = 15 mg/m3), and Table III reports mean 8-hr TWAs as 1.4 and 0.30
• performance ratio. TPM and Cr(VI) area means for downwind tripods were 4.8 mg/m3 TPM
• Upwind, TPM was below the LOD, while Cr(VI) means were 0.29 µg/m3 and 0.46 µg/m3
• Aircraft Topcoat Painting—During the topcoat phase, mean HDI monomer 8-hr
• TWAs were 5.95 µg/m3 for sprayers and 0.645 µg/m3 for hosemen (Table III). None of the
• than 1% HDI monomer, making pertinent the use of an OEL that encompasses exposure to
• 8-hr TWAs in Table IV show 50.9 µg/m3 for sprayers and 7.29 µg/m3 for hosemen.
• Table III shows mean personal exposures for sprayers during topcoat application: 32.2 µg/m3
• oligomer, and 45.2 µg/m3 TRIG. Means were formed from the individual results in Table X.
• acetate as clearly above LODs, with PBZ sample means 9.2, 0.95, 1.6, and 4.7 ppm,
• respectively, for sprayers and 1.8, 0.88, 1.2, and 0.94 ppm, for hosemen. While 8-hr TWAs
• sprayers as a job category had MAK and n-butyl acetate 8-hr TWAs of 1.7 and 0.86 ppm,
• respectively, with 0.29 ppm and 0.15 ppm for hosemen. All personal samples were below the
• 150 ppm), and topcoat painting was the only phase with concentrations above the LOD.
• titanium was detected at notable levels, with means 39 µg/m3 on tripod #1 and 45 µg/m3 on
• booth,” which requires 100 fpm (0.508 m/s). With mean Cr(VI) concentrations during
• comfortable margin of safety, as the highest individual and 95th percentile 8-hr TWAs were
• strategies additional to ventilation. Table IV shows Worker 007 having the highest exposures
• As monomeric HDI represents less than 1% of the NCO content of HDI paint products,
• Nitroethane 79-24-3 3.4 TWA 100 ppm TWA 100 ppm NIOSH IDLH 1000 ppm
• Trimethylbenzene 95-63-6 0.9 NIOSH IDLH 1000 ppm
• 1,3,5- NA TWA 25 ppm ACGIH TLV TWA 25 ppm; NIOSH IDLH 1000
• TWA 50 ppm TWA 5 ppm ACGIH TLV TWA 20 ppm; NIOSH IDLH 700

Methods (brief)

• isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means
• oligomer as NCO group mass—showed six of 15 personal samples exceeded the United Kingdom
• of 30 sampled workers. Four areas were sampled (Figure 2) per survey for a total of twelve.
• Each sampled worker and area sample tripod was fitted with multiple pumps and sampling
• Using Material Safety Data Sheets (MSDS) as a guide, air samples were collected for select
• zinc chromate. During the aircraft wipe-down phase, only VOC samples were collected.
• VOCs, TPM, Cr(VI), select metals, and nitroethane samples were collected during the
• primer phase. VOCs, TPM, select metals, and HDI air samples were collected during the
• topcoat phase. Both personal breathing zone (PBZ) and area air samples were collected
• during all phases. PBZ samples were collected by attaching, to a worker’s belt, an air
• sampling pump connected by Tygon® tubing to the sample media, attached to the outside of
• their Tyvek® hood. Area samples were collected on tripods at four corners surrounding the
• Figure 2. The area sample media were approximately 5 ft above the floor.
• VOCs sampled included: 2-butoxyethanol, also known ethylene glycol butyl ether (EGBE);
• trimethylbenzene; and 1,3,5-trimethylbenzene. Samples were collected on charcoal tubes
• TPM and Cr(VI) air samples were collected on pre-weighed polyvinyl chloride (PVC) filters
• select metals sampled included barium (Ba), chromium (Cr), copper (Cu), tin (Sn),
• strontium (Sr), and titanium (Ti), collected on pre-weighed PVC filters (37 mm diameter and

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Tin
• Chromium

Verification notes

• Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
• Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
• Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
• Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
• HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.