George W. Giles v. Carmi flavor and Frangrance Company, Inc., 2015 Mo. App. LEXIS 965

Giles worked as a maintenance worker/welder at Ventura Foods (1997–2003) and was exposed to diacetyl used in butter flavoring. He developed respiratory symptoms (shortness of breath, cough, wheeze) beginning ~1999.
In 2001 Giles was referred to pulmonologist Dr. Yagan; both learned of published reports linking diacetyl to bronchiolitis obliterans from a popcorn plant cluster and obtained an MSDS confirming diacetyl at Giles’s workplace.
Dr. Yagan treated Giles, initially suspected occupational exposure but ultimately diagnosed asthma (methacholine challenge positive), ruled out interstitial lung disease, cleared Giles to return to work in January 2002, and did not diagnose bronchiolitis obliterans.
Giles saw another pulmonologist in 2005 who likewise diagnosed asthma and did not link the condition to diacetyl exposure. No physician diagnosed bronchiolitis obliterans until Dr. Parmet in 2011.
Giles filed suit in January 2012 (original action filed earlier and refiled consistent with the savings statute). Defendants moved for summary judgment on statute-of-limitations grounds (five-year limitations under Mo. Rev. Stat. § 516.120 and accrual rule in § 516.100).
The trial court granted summary judgment; the Court of Appeals reversed, holding a genuine factual dispute exists about when Giles’s damages were "capable of ascertainment."

Issue	Plaintiff's Argument	Defendant's Argument	Held
When did Giles’s cause of action accrue under the "capable of ascertainment" standard in § 516.100?	Giles: accrual did not occur until a diagnosis of bronchiolitis obliterans in 2011; earlier symptoms and speculation did not make damages objectively ascertainable.	Respondents: knowledge of symptoms and contemporaneous medical/scientific literature (and Dr. Yagan’s early concern) put a reasonably prudent person on notice well before 2007, so limitations expired.	Reversed summary judgment — a genuine factual dispute exists as to whether damages were "capable of ascertainment" before Jan. 4, 2007; defendants did not meet their burden on the affirmative defense.

Powel v. Chaminade Coll. Preparatory, Inc., 197 S.W.3d 576 (Mo. banc 2006) (articulates "capable of ascertainment" test: accrual occurs when a reasonably prudent person is on notice of a potentially actionable injury)
Elmore v. Owens-Illinois, Inc., 673 S.W.2d 434 (Mo. banc 1984) (occupational disease accrues at physician diagnosis when diagnosis is the first time condition and cause "come together")
Ray v. Upjohn Co., 851 S.W.2d 646 (Mo. App. S.D. 1993) (statute begins when plaintiff is aware of condition and its cause; diagnosis triggered accrual)
Reasons v. Union Pacific R.R. Co., 886 S.W.2d 104 (Mo. App. E.D. 1994) (plaintiff must know or have reason to know of permanent damage and its cause; mere suspicion is insufficient)
Grady v. Amrep, Inc., 139 S.W.3d 585 (Mo. App. E.D. 2004) (damages can be ascertainable at time of exposure when fact of damage and cause are evident without later diagnosis)
Ahearn v. Lafayette Pharmacal, Inc., 729 S.W.2d 501 (Mo. App. E.D. 1987) (medical community knowledge of causal connection can make damages objectively ascertainable even if plaintiff is unaware)