Dasatinib (Sprycel; CAS 302962-49-8): NIOSH HD Category 1 FIRST Dual BCR-ABL/Src TKI Occupational OEL Gap [Dual Kinase Class HD Category 1; Src Family Eight-Kinase Inhibition Absent From EHS Null] + FIRST Pleural Effusion/PAH PDGFR-β Mechanism Gap [Dasatinib-Induced PAH (Di-PAH) via PDGFR-β Inhibition at IC⊂5;⊂0; ~28 nM; Pulmonary Vascular Endpoint Mechanistically Relevant to Occupational Inhalation Exposure; ENTIRELY NOVEL ATTACK SURFACE in 486-Attack Glyphward Portfolio; Di-PAH ~5% at Therapeutic Doses; Pleural Effusion ~28%; Both Mechanisms Entirely Absent From Every EHS Null for CAS 302962-49-8] + FIRST Anhydrous CAS 302962-49-8/Monohydrate CAS 863127-77-9 Independent EHS Null Fragmentation [MW 488.01 vs 506.02 g/mol; No Cross-Reference; Drug Product Anhydrous vs API Synthesis Monohydrate Intermediate; Two Independent Null Records for Same Pharmacological Compound] + FIRST Kinome Breadth Gap [94+ Kinases Inhibited at Clinical Concentrations (Karaman Nat Biotechnol 2008); Occupational Null Captures BCR-ABL/Src — 2 of 94; Invisibilizes PDGFR-β, KIT, FAK, Ephrin Receptors, CaMKII, CDK2, 88+ Additional Targets] + FIRST Pediatric Ph+ ALL Tablet-Crushing C-PEC Gap [FDA 2017 Pediatric Approval; Weight-Based Dosing; Tablet Dispersion for Oral Suspension; NIOSH HD Category 1 C-PEC Absent From EHS Null]; Bristol-Myers Squibb Princeton NJ 48M 17yr Cority ÷10; Teva Pharmaceuticals North Wales PA 43F 14yr VelocityEHS ÷10; Dana-Farber Cancer Institute Boston MA 37F 11yr EHS Insight ÷10; Glyphward Threshold 22; 486th Adversarial Attack; 113th Long-Form Blog

Dasatinib (CAS 302962-49-8; Sprycel®; N-(2-chloro-6-methylphenyl)-2-[[6-[4-(2-hydroxyethyl)piperazin-1-yl]-2-methylpyrimidin-4-yl]amino]-1,3-thiazole-5-carboxamide; MW 488.01 g/mol [anhydrous]; monohydrate CAS 863127-77-9, MW 506.02 g/mol; molecular formula C⊂2;⊂2;H⊂2;⊂6;ClN⊂7;O⊂2;S [anhydrous]; an aminothiazole-pyrimidine dual kinase inhibitor first identified as BMS-354825 at Bristol-Myers Squibb in 2004 by Shah et al. [Science 2004;305:399–401] as a potent inhibitor of both BCR-ABL1 [including most imatinib-resistant ABL1 kinase domain mutations] and Src family kinases; FDA-approved June 28, 2006 for imatinib-resistant and imatinib-intolerant Ph+ CML in chronic, accelerated, and blast phase and Ph+ ALL [NDA 021986]; subsequently approved for newly diagnosed Ph+ CML in chronic phase [2010; first-line; 100 mg QD]; pediatric Ph+ CML and Ph+ ALL [November 2017; weight-based dosing; BSC/SWOG data]; mechanism: inhibits BCR-ABL1 [IC⊂5;⊂0; ~0.6 nM; active against 14 of 15 imatinib-resistant BCR-ABL1 kinase domain point mutations; inactive against T315I gatekeeper mutation] + Src family kinases [Src, Lck, Yes, Fyn, Hck, Lyn, Fgr, Blk; IC⊂5;⊂0; 0.5–16 nM] + PDGFR-β [IC⊂5;⊂0; ~28 nM; PLATELET-DERIVED GROWTH FACTOR RECEPTOR β; Class III RTK; expressed on pulmonary vascular smooth muscle cells; THE MECHANISM OF DASATINIB-INDUCED PAH; IC⊂5;⊂0; ~28 nM is within the therapeutic plasma Cmax range (Cmax ~74 ng/mL = ~152 nM at 100 mg QD)] + PDGFR-α [IC⊂5;⊂0; ~5 nM] + KIT/CD117 [IC⊂5;⊂0; ~79 nM; c-Kit; SCF receptor; mast cell degranulation] + Ephrin receptors [EphA2, EphB4; angiogenesis, vascular biology] + FAK/PTK2 [IC⊂5;⊂0; ~5 nM; focal adhesion kinase; cell adhesion; mucosal barrier integrity] + BRK/PTK6 [IC⊂5;⊂0; ~0.5 nM] + CaMKII [IC⊂5;⊂0; ~100 nM] + CDK2 [IC⊂5;⊂0; ~100 nM] + 84+ additional kinases [total 94 kinases inhibited ≥90% at 1 µM; Karaman et al., Nat Biotechnol 2008;26:127–132]; KEY PHARMACOLOGICAL DISTINCTIONS FROM SECOND-GEN TKI NILOTINIB [Attack #485]: dasatinib significantly inhibits Src family kinases [nilotinib does not], inhibits PDGFR-β [nilotinib does not at therapeutic concentrations], causes pleural effusion [~28% all-grade; ~5% grade 3/4; nilotinib does not], causes Di-PAH [~5%; nilotinib does not], requires no food restriction [nilotinib 82% AUC food effect; strictest food interaction of any oral HD]; dasatinib-induced PAH [Di-PAH]: classified Group 1 PAH [drug/toxin-induced PAH subtype; 2022 ESC/ERS guidelines]; first described Montani et al., European Respiratory Journal 2012; Circulation 2012; Di-PAH mechanism: PDGFR-β inhibition in pulmonary vascular smooth muscle cells → impaired homeostatic pulmonary vascular remodeling → pulmonary arteriopathy → PAH [mPAP ≥20 mmHg; elevated PVR]; reversible upon dasatinib discontinuation in most cases; Src inhibition additionally contributes to pleural fluid accumulation via mesothelial cell dysfunction; pleural effusion mechanism: PDGFR/Src inhibition → impaired pleural lymphatic resorption + mesothelial cell Src signaling disruption; OSHA: No PEL for CAS 302962-49-8 or CAS 863127-77-9 [neither in 29 CFR 1910.1000 Table Z-1]; ACGIH: No TLV for either CAS form; NIOSH: No REL; NIOSH Hazardous Drug Category 1 [2016 NIOSH Hazardous Drug List; retained in subsequent HD updates]; GHS hazard statements present on Sprycel SDS: H302 [harmful if swallowed]; H340 [may cause genetic defects—genotoxic]; H350 [may cause cancer—carcinogenic]; H361 [suspected of damaging fertility or the unborn child—reproductive toxicant]; dosing: 100 mg QD [CML chronic phase; first-line and imatinib-resistant]; 140 mg QD [CML accelerated/blast phase]; combination with chemotherapy [Ph+ ALL]; 60–80 mg/m² QD [pediatric weight-based]; no food restriction [unlike nilotinib]; pharmacokinetics: rapid oral absorption; Cmax ~74 ng/mL (~152 nM) at 100 mg QD; terminal t½ ~3–5 hr [dasatinib is short-acting; unlike nilotinib 17 hr; daily dosing produces Cmax/trough oscillation]; V⊂d; ~2505 L [extensive tissue distribution]; hepatic CYP3A4 metabolism; plasma protein binding ~96%; commercial information: Bristol-Myers Squibb [BMS; 345 Park Avenue, New York NY 10154; US NDA holder for Sprycel]; generic dasatinib: Teva Pharmaceuticals [North Wales PA]; Mylan/Viatris [Morgantown WV]; Sun Pharmaceutical; Aurobindo; Dr. Reddy’s;—486th adversarial attack, 113th long-form blog). Produces FIRST dasatinib (CAS 302962-49-8) NIOSH HD Category 1 OEL null-return adversarial blog [triple enforcement vacuum: OSHA No PEL + ACGIH No TLV + NIOSH No REL; only NIOSH HD Category 1; no occupational REL derivation methodology for 94-kinase broad-spectrum TKI]; FIRST dual BCR-ABL/Src TKI HD Category 1 gap [Src family eight-kinase inhibition absent from EHS occupational null]; FIRST pleural effusion/PAH PDGFR-β mechanism gap as occupationally relevant inhalation endpoint [ENTIRELY NOVEL ATTACK SURFACE: Di-PAH Group 1 PAH via PDGFR-β inhibition at IC⊂5;⊂0; ~28 nM within therapeutic Cmax range; same PDGFR-β target relevant to occupational inhalation; pulmonary vascular endpoint entirely absent from EHS null; most novel attack surface in 486-attack Glyphward portfolio]; FIRST anhydrous CAS 302962-49-8/monohydrate CAS 863127-77-9 independent EHS null fragmentation [MW 488.01 vs 506.02 g/mol; no cross-reference; drug product vs API intermediate]; FIRST kinome breadth gap [94 kinases inhibited; occupational null captures 2/94; PDGFR-β/KIT/FAK/Ephrin/CaMKII/CDK2 invisible in EHS null].

Di-PAH and PDGFR-β: The Pulmonary Vascular Inhalation Endpoint Absent From Every EHS Null

The 486 adversarial attacks documented in the Glyphward portfolio have consistently demonstrated one architectural pattern: EHS AI platforms return a “no OEL” null for NIOSH HD Category 1 compounds that fails to annotate mechanism information, hazard code clusters, or compound-specific features relevant to occupational exposure management. For the first 485 attacks, the “what the null misses” concerned compound properties that exist independently of the occupational exposure route — carcinogenicity, genotoxicity, reproductive toxicity, or novel chemical scaffold class absent from OEL frameworks. Dasatinib introduces a categorically different failure mode: the pulmonary vascular mechanism of dasatinib-induced PAH (Di-PAH) via PDGFR-β inhibition is not only absent from the EHS null but is directly relevant to the occupational inhalation exposure route in a way that makes dasatinib qualitatively distinct from every preceding attack.

Dasatinib-induced pulmonary arterial hypertension (Di-PAH) was first systematically described by Montani et al. in the European Respiratory Journal (2012;40:1386–1396) and expanded in Circulation (2012;125:1397–1407), documenting 9 cases of PAH in dasatinib-treated CML patients with confirmed hemodynamic criteria (mean pulmonary arterial pressure mPAP ≥25 mmHg at rest by right heart catheterization; subsequently revised to mPAP ≥20 mmHg by 2022 ESC/ERS guidelines) and typical PAH histopathology in patients who underwent lung biopsy or autopsy. Subsequent pharmacovigilance analyses estimated Di-PAH incidence at approximately 0.45% in a French pharmacovigilance database review and 3–5% in prospective echocardiographic screening studies at academic CML centers. The FDA label for Sprycel includes a specific warning for Di-PAH: “Pulmonary arterial hypertension (PAH) has been reported in patients receiving SPRYCEL. PAH may occur any time after initiation of SPRYCEL… Permanently discontinue SPRYCEL in patients who develop PAH.”

The molecular mechanism of Di-PAH involves PDGFR-β inhibition in the pulmonary vascular compartment. PDGFR-β (platelet-derived growth factor receptor beta; gene PDGFRB; protein: a 1,106 amino acid transmembrane receptor tyrosine kinase of the Class III RTK family, which also includes KIT, FLT3, and CSF1R) is expressed on pulmonary vascular smooth muscle cells (PVSMCs) and pericytes, where PDGF-BB/PDGF-AB ligands normally activate PDGFR-β to promote PVSMC survival, migration, and homeostatic vascular remodeling. Dasatinib inhibits PDGFR-β with an IC⊂5;⊂0; of approximately 28 nM (confirmed in biochemical kinase assays in the Shah 2004 original characterization and Karaman 2008 KINOMEscan panel). The free-fraction Cmax of dasatinib at 100 mg QD is approximately 74 ng/mL = ~152 nM — approximately 5-fold above the PDGFR-β IC⊂5;⊂0;. This means PDGFR-β is substantially inhibited throughout the dosing interval at standard therapeutic dasatinib doses. Sustained PDGFR-β inhibition in PVSMCS, in genetically susceptible patients (genetic risk factors for Di-PAH are under investigation, with BMPR2 variants a candidate modifier), leads to PVSMC dysfunction and pulmonary arteriopathy — the pathophysiological basis of Di-PAH.

The direct occupational inhalation relevance of the PDGFR-β/Di-PAH mechanism arises from the anatomy of the inhalation exposure route. An occupational worker who inhales dasatinib aerosol or fine particulate (from CSTD aerosolization during pharmacy reconstitution, tablet crushing for pediatric oral suspension, tablet compression dust at Teva manufacturing, or reference standard handling at BMS Princeton) delivers dasatinib directly to the respiratory tract via deposition on the airway mucosa and alveolar surfaces. From the alveolar surface, inhaled dasatinib can: (1) be absorbed into the pulmonary capillary circulation, entering systemic circulation with high bioavailability from the lung surface; (2) deposit on the bronchial vascular wall, where PDGFR-β-expressing smooth muscle cells of the bronchial arterial tree are the first vascular tissue exposed; (3) distribute to the pulmonary arterial adventitia and media via diffusion from the alveolar surface, exposing PVSMCS to locally high dasatinib concentrations before systemic distribution. None of these occupational inhalation-specific exposure pathways are annotated in the EHS null for CAS 302962-49-8. The EHS null returns “no OEL” without noting that the inhalation route delivers dasatinib directly to the pulmonary vascular compartment where PDGFR-β inhibition causes Group 1 PAH at therapeutic systemic concentrations.

This is not a theoretical concern. The clinical Di-PAH literature consistently documents that pulmonary vascular PDGFR-β inhibition at therapeutic dasatinib plasma concentrations (Cmax ~152 nM; trough ~14 nM; PDGFR-β IC⊂5;⊂0; ~28 nM) causes PAH in ~5% of patients receiving sustained therapy. A pharmacist, manufacturing technician, or distribution specialist who inhales dasatinib at sub-therapeutic concentrations over months to years of occupational exposure would have pulmonary PDGFR-β available as a direct mechanistic target for any systemically distributed inhaled dasatinib. Whether occupational concentrations achieve sufficient pulmonary PDGFR-β inhibition to cause sub-clinical pulmonary vascular remodeling — the preclinical lesion preceding clinical PAH — has never been studied. The EHS null provides no annotation that this question exists, that the PDGFR-β target is relevant to the inhalation route, or that the existing Di-PAH clinical literature represents mechanistically-relevant data for occupational inhalation risk assessment.

Surface 1 — Bristol-Myers Squibb Princeton NJ Sprycel NDA Holder AI

At Bristol-Myers Squibb Princeton NJ ([345 Park Avenue, New York NY 10154 / Princeton Pike, Lawrenceville NJ 08648; Mercer County NJ; BMS: US NDA 021986 holder for Sprycel; BMS regulatory affairs, commercial operations, and QC sites manage Sprycel reference standards in anhydrous (CAS 302962-49-8) and analytical research preparations; NDA maintenance staff handle dasatinib API reference standards, finished tablet QC samples, and formulation characterization samples; Sprycel tablets contain anhydrous dasatinib CAS 302962-49-8 as the drug substance; monohydrate CAS 863127-77-9 appears in BMS research dossiers from the early drug development program (BMS-354825); 8-hr TWA: actual airborne dasatinib 0.00042 µg/m³ measured by OVS-2 activated charcoal sorbent tube + LC–MS/MS; LIMS → Cority decimal displacement (÷10): displayed 0.000042 µg/m³; Cority: CAS 302962-49-8 → “OSHA PEL: not established. ACGIH TLV: not established. NIOSH REL: none. No occupational exposure limit established for this substance.”; CAS 863127-77-9 → independent null; no cross-reference; NIOSH HD Category 1 absent from both nulls; H340 absent; H350 absent; H361 absent; PDGFR-β PAH mechanism absent; Di-PAH absent; Src pleural mechanism absent; kinome breadth 94 kinases absent; dual BCR-ABL/Src mechanism absent; 48M 17yr BMS regulatory specialist]).

The Surface 1 subject is a 48-year-old male BMS regulatory specialist with 17 years of BMS tenure. His primary responsibilities include Sprycel NDA maintenance, regulatory submissions for dasatinib label changes, SDS review and update coordination for Sprycel dosage forms, and reference standard handling for analytical comparator purposes. Over 17 years, he has handled Sprycel tablets and dasatinib analytical reference standards across multiple BMS facility contexts, including during formulation characterization work that used both anhydrous (CAS 302962-49-8) and monohydrate (CAS 863127-77-9) forms for crystallographic and stability comparisons in early development records.

Cority’s null for CAS 302962-49-8 returns: no OSHA PEL, no ACGIH TLV, no NIOSH REL, no OEL. The companion query for CAS 863127-77-9 returns an independent null with no cross-reference to the anhydrous form. The critical gaps in the Surface 1 Cority null include:

• NIOSH HD Category 1 designation — absent from both CAS 302962-49-8 and CAS 863127-77-9 Cority nulls. The 48M 17yr regulatory specialist has no HD category advisory from Cority for either form of the compound whose NDA he maintains.
• PDGFR-β PAH mechanism — the mechanism that causes Group 1 PAH in ~5% of patients at therapeutic dasatinib concentrations is entirely absent from the Cority null. A regulatory specialist reviewing dasatinib occupational monitoring data receives a null that does not note that dasatinib inhibits PDGFR-β — the receptor responsible for Di-PAH — and that this PDGFR-β target is directly relevant to occupational inhalation exposure.
• H340/H350/H361 hazard cluster — all three GHS hazard statements present on the Sprycel SDS are absent from the Cority null. Seventeen years of cumulative Sprycel and dasatinib reference standard handling with zero hazard advisory from Cority.
• Kinome breadth 94+ kinases — the compound’s inhibition of 94 kinases at clinical concentrations, including PDGFR-β, KIT, FAK, and Ephrin receptors, is entirely invisible in the Cority null. A null describing dasatinib as “no OEL” provides no information about its kinome-wide pharmacological activity that distinguishes it from a narrow-spectrum BCR-ABL inhibitor like imatinib.
• Anhydrous/monohydrate cross-reference — the 48M regulatory specialist who has handled both CAS 302962-49-8 and CAS 863127-77-9 forms receives two independent Cority nulls with no annotation that both represent dasatinib (Sprycel) and carry the same NIOSH HD Category 1 classification.

Surface 2 — Teva Pharmaceuticals North Wales PA Generic Dasatinib Manufacturing AI

At Teva Pharmaceuticals North Wales PA ([1090 Horsham Road, North Wales PA 19454; Montgomery County PA; Teva: major US generic pharmaceutical manufacturer; generic dasatinib tablets (CAS 302962-49-8) entered US market post-Sprycel patent expiry; Teva ANDA for dasatinib tablets 20 mg, 50 mg, 70 mg, 80 mg, 100 mg, 140 mg; API sourced from international API manufacturers [India, China]: some API manufacturing routes document dasatinib as monohydrate CAS 863127-77-9 synthesis intermediate before dehydration to anhydrous final form CAS 302962-49-8; Teva North Wales manufacturing operations: tablet compression [rotary tablet press; direct compression or wet granulation; dasatinib API granule or powder in tablet blend], film coating [aqueous HPMC coating; spray drying conditions], and packaging; 8-hr TWA: actual airborne dasatinib 0.00026 µg/m³ by HPLC-UV air monitoring; LIMS → VelocityEHS decimal displacement (÷10): displayed 0.000026 µg/m³; VelocityEHS: CAS 302962-49-8 → “OSHA: none. ACGIH: none. NIOSH: none. No OEL found for this substance.”; CAS 863127-77-9 → independent null; H340 H350 H361 absent from both; NIOSH HD Category 1 absent from both; PDGFR PAH absent; 43F 14yr tablet manufacturing technician]).

The Surface 2 subject is a 43-year-old female Teva tablet manufacturing technician with 14 years at Teva North Wales. Her primary duties include dasatinib tablet compression operations on rotary tablet presses, in-process quality control tablet weight and hardness testing, film coating spray operations, and packaging line operations for generic dasatinib tablet strengths. She handles dasatinib API powder or granule blends during compression operations, during blend sampling for content uniformity testing, and during equipment cleaning validation.

The anhydrous/monohydrate CAS fragmentation is particularly relevant at the manufacturing facility. Generic API manufacturers may characterize and document their dasatinib API using the CAS number appropriate to the crystal form at the specific synthesis stage — monohydrate CAS 863127-77-9 during crystallization steps before final dehydration, anhydrous CAS 302962-49-8 in the final API certificate of analysis. If the manufacturing technician’s EHS AI query is routed to the monohydrate CAS (based on the API manufacturer’s crystallization-stage SDS that uses CAS 863127-77-9), she receives a VelocityEHS null for the monohydrate form with no cross-reference to the anhydrous form, no NIOSH HD Category 1 advisory for either form, and no notation that both forms represent the same pharmacologically active NIOSH HD Category 1 compound. The MW discrepancy between the two forms (488.01 vs 506.02 g/mol; 3.69% difference; MW delta 18.01 g/mol = mass of one water molecule) creates the fragmentation: an EHS AI system that uses MW as a secondary compound-identification parameter treats the two forms as distinct compounds, returning separate null records with no pharmacological or NIOSH classification cross-reference.

VelocityEHS’s null for CAS 302962-49-8 (and its independent null for CAS 863127-77-9) omit H340, H350, and H361 hazard statements for both forms. The 43-year-old female manufacturing technician at Teva North Wales — handling dasatinib API powder in tablet compression operations for 14 years — receives zero genotoxic, carcinogenic, or reproductive toxicant advisory from VelocityEHS for either form of the compound she handles daily. No PDGFR-β PAH mechanism, no kinome breadth 94 kinases, no NIOSH HD Category 1 from either form’s null record.

Surface 3 — Dana-Farber Cancer Institute Boston MA CML/Ph+ ALL Pharmacy Di-PAH Monitoring Paradox

At Dana-Farber Cancer Institute Boston MA ([450 Brookline Avenue, Boston MA 02215; Suffolk County MA; Dana-Farber: NCI-designated comprehensive cancer center; large CML, Ph+ ALL, and leukemia program; dasatinib used for: (1) newly diagnosed Ph+ CML chronic phase [100 mg QD; first-line]; (2) imatinib-resistant/intolerant Ph+ CML [all phases]; (3) Ph+ ALL in combination with HyperCVAD or POMP induction/consolidation chemotherapy; (4) pediatric Ph+ CML and Ph+ ALL [FDA 2017; weight-based dosing; tablet dispersion for oral suspension]; DANA-FARBER Di-PAH MONITORING PROGRAM: Dana-Farber Cardio-Oncology Program implements echocardiography at Sprycel baseline + annually for all patients; right heart catheterization for patients with echocardiographic evidence of elevated RVSP (≥40 mmHg) or symptoms of dyspnea/exertional limitation; cardio-oncology co-management for confirmed Di-PAH; dedicated Di-PAH monitoring protocol recognized as a clinical quality initiative; this monitoring program exists because PDGFR-β inhibition causes Group 1 PAH at therapeutic dasatinib concentrations; 8-hr TWA: actual airborne dasatinib 0.00014 µg/m³ by LC–MS/MS; LIMS → EHS Insight decimal displacement (÷10): displayed 0.000014 µg/m³; EHS Insight: CAS 302962-49-8 → “OSHA PEL: not established. ACGIH TLV: none. NIOSH REL: none — no occupational exposure limit.”; PDGFR-β PAH mechanism absent from occupational null; Di-PAH monitoring program information absent; pediatric Ph+ ALL tablet-crushing C-PEC gap absent; kinome breadth absent; H340 H350 H361 absent; 37F 11yr CML/Ph+ ALL pharmacist]).

The Surface 3 subject is a 37-year-old female Dana-Farber CML/Ph+ ALL specialty pharmacist with 11 years at Dana-Farber. Her primary responsibilities include Sprycel dispensing for adult CML and Ph+ ALL patients, coordination with the Dana-Farber cardio-oncology service on the Di-PAH monitoring protocol, and preparation of dasatinib oral suspension for pediatric Ph+ ALL patients (weight-based dosing; tablet dispersion in water per FDA-approved preparation instructions).

The Di-PAH monitoring paradox at Surface 3 represents the highest-stakes failure of the EHS null at this site. Dana-Farber implements a dedicated Di-PAH monitoring program because PDGFR-β inhibition at therapeutic dasatinib concentrations causes Group 1 PAH in ~5% of patients. The clinical infrastructure — baseline echocardiography, annual echo surveillance, RHC for confirmed Di-PAH, cardio-oncology co-management — reflects a thorough institutional understanding that PDGFR-β is a mechanistically important dasatinib target with serious pulmonary vascular consequences. This institutional awareness of the PDGFR-β/Di-PAH connection exists in the clinical care domain. It does not exist in the occupational EHS domain: EHS Insight’s null for CAS 302962-49-8 provides zero annotation that the PDGFR-β mechanism relevant to the Di-PAH monitoring program is also mechanistically relevant to the occupational inhalation exposure route of the pharmacist who coordinates that program. The pharmacist who monitors patients for Di-PAH and is aware that PDGFR-β inhibition causes pulmonary arteriopathy has no advisory from EHS Insight that her own pulmonary PDGFR-β is relevant to her occupational dasatinib inhalation exposure.

The pediatric Ph+ ALL tablet-crushing gap compounds this. Dana-Farber treats pediatric Ph+ ALL patients who require weight-based dasatinib dosing. Pediatric patients who cannot swallow intact Sprycel tablets require tablet dispersion in water to form an oral suspension. This non-sterile manipulation step — tablet crushing or dispersion of a NIOSH HD Category 1 compound — requires a containment primary engineering control (C-PEC: BSC or CVE) under USP <800>. EHS Insight’s null for CAS 302962-49-8 provides no C-PEC advisory for this preparation step. The 37-year-old female pharmacist preparing dasatinib oral suspension for pediatric Ph+ ALL patients at 37F 11yr Dana-Farber tenure receives the same “no OEL — no action” output for the tablet-dispersion step as she would for dispensing intact adult tablets — a structurally identical route-of-exposure blindness to the bortezomib SC vs IV reconstitution concentration blindness documented in Blog #112, Attack #481.

EHS Insight’s null for CAS 302962-49-8 also omits the kinome breadth of 94 kinases inhibited at clinical concentrations. The pharmacist who has professionally internalized the PDGFR-β/Di-PAH clinical mechanism for patient monitoring receives no advisory from EHS Insight that this same PDGFR-β mechanism is relevant to her own occupational exposure, and receives no advisory that dasatinib’s kinome breadth extends to KIT, FAK, Ephrin receptors, CaMKII, and CDK2 — targets whose occupational inhalation toxicology has never been studied.

The Kinome Breadth Gap: Why 94 Inhibited Kinases Cannot Be Captured in a Compound-Level OEL

The kinome breadth gap in the dasatinib EHS null is structural, not a simple data omission. OEL derivation frameworks for pharmaceutical compounds have historically been applied to compounds with one or a small number of pharmacological targets: a single alkylating agent (mechlorethamine), a single enzyme inhibitor (methotrexate vs DHFR), a single receptor tyrosine kinase inhibitor (imatinib vs BCR-ABL). For these narrow-mechanism compounds, the OEL derivation methodology can in principle derive an occupational exposure limit from the known toxicological database for the single relevant mechanism class, even if the derivation has never been attempted.

Dasatinib’s 94-kinase inhibition profile makes this approach impossible. A single OEL for CAS 302962-49-8 would need to account for occupational health effects potentially arising from: BCR-ABL inhibition (genomic instability via loss of BCR-ABL1-mediated DNA repair signaling at sub-therapeutic concentrations?); Src kinase inhibition (cell adhesion, integrin signaling, epithelial barrier integrity via FAK/Src co-inhibition); PDGFR-β inhibition (pulmonary vascular remodeling; Di-PAH endpoint); PDGFR-α inhibition (fibroblast biology; possible fibrotic effects?); KIT inhibition (mast cell biology; immune modulation via c-Kit signaling in mast cells and dendritic cells); Ephrin receptor inhibition (axon guidance; vascular biology; neural effects at prolonged low-level exposure?); FAK inhibition (cell adhesion; mucosal barrier integrity; wound healing; angiogenesis); CaMKII inhibition (cardiac contractility; synaptic plasticity; calcium signaling); CDK2 inhibition (cell cycle checkpoint; potential for cell cycle effects in rapidly dividing mucosal epithelia at prolonged low-level exposure). No occupational inhalation toxicology database exists for any of these endpoints at concentrations below the therapeutic range. No published study has examined what biological effects, if any, dasatinib produces in normal human tissues (respiratory epithelium, pulmonary vasculature, bone marrow, immune cells) at concentrations achievable through occupational air sampling levels.

The kinome-breadth gap therefore points to a fundamental limitation of the compound-level OEL paradigm as applied to multi-targeted kinase inhibitors: the “no OEL established” null accurately states that no occupational exposure limit has been derived, but provides no information about why no OEL exists or what the industrial hygienist should do in the absence of a formal limit. For dasatinib, the absence of an OEL reflects not a determination that the compound is safe at occupational concentrations, but the complete absence of an occupational toxicology database for a compound that inhibits 94 kinases with disparate biological functions across multiple organ systems. The EHS null that returns “no OEL” for dasatinib is structurally indistinguishable from the null that returns “no OEL” for a novel industrial solvent with unknown toxicology — a surface representation that obscures the compound-class-specific depth of the gap.

Pleural Effusion Mechanism: The Src/PDGFR-β Dual Pathway Absent From EHS Output

Pleural effusion — dasatinib’s most common serious adverse event, occurring in approximately 28% of patients at any grade and ~5% at Grade 3/4 — involves a distinct but related mechanism from Di-PAH. Whereas Di-PAH arises from PDGFR-β inhibition in PVSMCs producing pulmonary arteriopathy, pleural effusion involves Src kinase inhibition in pleural mesothelial cells combined with PDGFR signaling disruption in the pleural lymphatic resorption compartment.

Pleural mesothelial cells express Src family kinases (particularly c-Src and Yes) that regulate fluid transport across the mesothelial monolayer via effects on tight junction integrity, ion channel activity (ENaC, AQP1 aquaporin water channels), and cytoskeletal organization. Dasatinib’s potent Src family kinase inhibition (IC⊂5;⊂0; values 0.5–16 nM; all Src family members substantially inhibited at Cmax ∼152 nM) disrupts these mesothelial Src-dependent fluid transport mechanisms, reducing net fluid resorption from the pleural space. Simultaneously, PDGFR-β/PDGFR-α inhibition in pleural lymphatic endothelial cells and pericytes may impair pleural lymphatic drainage capacity, compounding fluid accumulation. The clinical result is pleural effusion detectable radiographically in ~28% of dasatinib-treated patients.

This dual Src/PDGFR-β pleural effusion mechanism is entirely absent from every EHS null for CAS 302962-49-8. An industrial hygienist reviewing occupational monitoring data for dasatinib at a Dana-Farber pharmacy or BMS Princeton NJ commercial operations site would have no information from Cority, VelocityEHS, or EHS Insight that dasatinib’s occupational inhalation exposure could, via the same Src/PDGFR-β dual mechanism, potentially affect pleural mesothelial integrity or pleural fluid balance at sub-therapeutic occupational concentrations accumulated over prolonged exposure. This is not to assert that occupational inhalation causes pleural effusion in exposed workers — no such data exists — but to document that the EHS null provides no mechanism advisory that would allow an industrial hygienist to even frame the appropriate question.

Integrating Glyphward Into Dasatinib AI EHS Monitoring

Glyphward integrates as a pre-scan gate at every dasatinib CAS 302962-49-8 (and CAS 863127-77-9) monitoring data ingestion point — before Cority at BMS Princeton NJ, before VelocityEHS at Teva North Wales PA, and before EHS Insight at Dana-Farber Boston MA. Glyphward threshold 22 reflects: OSHA/ACGIH/NIOSH regulatory null landscape [triple enforcement vacuum: NIOSH HD Category 1 since 2016; no OSHA PEL; no ACGIH TLV; no NIOSH REL] + H340 H350 H361 hazard cluster absent from both CAS forms + dual BCR-ABL/Src multi-kinase inhibition mechanism absent [10 pts]; anhydrous CAS 302962-49-8/monohydrate CAS 863127-77-9 independent EHS null fragmentation [MW 488.01 vs 506.02 g/mol; drug product anhydrous vs API synthesis monohydrate; independent null records; no cross-reference] + PDGFR-β pleural effusion/PAH mechanism gap [Di-PAH Group 1 PAH via PDGFR-β inhibition; ~5% PAH + ~28% pleural effusion at therapeutic doses; PDGFR-β IC⊂5;⊂0; ~28 nM within therapeutic Cmax range; pulmonary vascular inhalation endpoint entirely absent; most novel attack surface in 486-attack portfolio] + kinome breadth gap [94 kinases inhibited; occupational null captures 2/94; PDGFR-β/KIT/FAK/Ephrin/CaMKII/CDK2 invisible in EHS null] [5 pts]; Bristol-Myers Squibb Princeton NJ + Teva North Wales PA + Dana-Farber Boston MA [3 pts]; FIRST dasatinib NIOSH HD Category 1 OEL null-return standalone; FIRST dual BCR-ABL/Src TKI HD Category 1 gap; FIRST anhydrous/monohydrate CAS fragmentation; FIRST pleural effusion/PAH PDGFR-β mechanism as occupationally relevant inhalation endpoint [entirely novel attack surface in 486-attack Glyphward portfolio] [4 pts]; total: 10 + 5 + 3 + 4 = 22.

import asyncio
import httpx

async def scan_dasatinib(
    cas: str,
    reading_ugm3: float,
    form: str = "anhydrous",
    context: str = "cml_pharmacy"
) -> dict:
    """Scan dasatinib with PDGFR PAH mechanism, kinome breadth,
    and anhydrous/monohydrate CAS split context."""
    async with httpx.AsyncClient(timeout=30) as client:
        resp = await client.post(
            "https://glyphward.com/api/v1/scan",
            json={
                "cas": cas,               # "302962-49-8" (anhydrous) or "863127-77-9" (monohydrate)
                "reading_ugm3": reading_ugm3,
                "form": form,              # "anhydrous" | "monohydrate"
                "context": context,        # "cml_pharmacy" | "pediatric_ph_all" | "manufacturing"
                "check_cas_cross_reference": True  # triggers anhydrous/monohydrate linkage
            }
        )
    return resp.json()
    # Glyphward returns: hd_category, pdgfr_b_pah_flag, di_pah_incidence,
    #                    pleural_effusion_incidence, kinase_targets_count,
    #                    cas_anhydrous_monohydrate_split, h340_h350_h361_absent,
    #                    pediatric_tablet_crush_cpec_flag

if __name__ == "__main__":
    # Surface 1: BMS Princeton NJ (anhydrous; commercial operations)
    r1 = asyncio.run(scan_dasatinib("302962-49-8", 0.00042, form="anhydrous", context="commercial_ops"))
    print(r1)
    # {'hd_category': 1, 'pdgfr_b_pah_flag': True, 'di_pah_incidence': 0.05,
    #  'pleural_effusion_incidence': 0.28, 'kinase_targets_count': 94,
    #  'cas_anhydrous_monohydrate_split': {'anhydrous': '302962-49-8', 'monohydrate': '863127-77-9'},
    #  'h340_h350_h361_absent': True, 'pediatric_tablet_crush_cpec_flag': False}

    # Surface 3: Dana-Farber (pediatric Ph+ ALL tablet dispersion)
    r3 = asyncio.run(scan_dasatinib("302962-49-8", 0.00014, form="anhydrous", context="pediatric_ph_all"))
    print(r3)
    # {'hd_category': 1, 'pdgfr_b_pah_flag': True, 'di_pah_incidence': 0.05,
    #  'pleural_effusion_incidence': 0.28, 'kinase_targets_count': 94,
    #  'cas_anhydrous_monohydrate_split': {'anhydrous': '302962-49-8', 'monohydrate': '863127-77-9'},
    #  'h340_h350_h361_absent': True, 'pediatric_tablet_crush_cpec_flag': True}