Tiered application of the neutral red release and EpiOcular™ assays for evaluating the eye irritation potential of agrochemical formulations.
Agrochemical formulations have been underrepresented in validation efforts for implementing alternative eye irritation approaches but represent a significant opportunity to reduce animal testing. This study assesses the utility of the neutral red release assay (NRR) and EpiOcular™ assay (EO) for predicting the eye irritation potential of 64 agrochemical formulations relative to Draize data. In the NRR, formulations with an NRR50 value ≤ 50 mg/mL were categorized as UN GHS Cat 1 and those >250 mg/mL were classified as UN GHS Non Classified (NC). The accuracy, sensitivity, and specificity were 78, 85 and 76% and 73, 85 and 61% for identifying UN GHS 1 and NC formulations, respectively. Specificity was poor for formulations with NRR50 > 50 to ≤250 mg/mL. The EO (ET-40 method) was explored to differentiate formulations that were UN GHS 1/2 and UN GHS NC. The EO resulted in accuracy, sensitivity, and specificity of 65%, 58% and 75% for identifying UN GHS NC formulations. To improve the overall performance, the assays were implemented using a tiered-approach where the NRR was run as a first-tier followed by the EO. The tiered-approach resulted in improved accuracy (75%) and balanced sensitivity (73%) and specificity (77%) for distinguishing between irritating and non-irritating agrochemical formulations.
The Dow Chemical Company, Midland, MI, USA. Electronic address: rssettivari@dow.com.
Raja S
RS
Settivari
Dow AgroSciences LLC, Indianapolis, IN, USA.
Ricardo Acosta
RA
Amado
Dow Chemical Services UK Ltd, Milton Park, Abingdon, Oxon, UK.
Marco
M
Corvaro
The Dow Chemical Company, Midland, MI, USA.
Nicolo R
NR
Visconti
The Dow Chemical Company, Midland, MI, USA.
Lynn
L
Kan
The Dow Chemical Company, Midland, MI, USA.
Edward W
EW
Carney
The Dow Chemical Company, Midland, MI, USA.
Darrell R
DR
Boverhof
Dow AgroSciences LLC, Indianapolis, IN, USA.
Sean C
SC
Gehen
D016475:3T3 Cells; D016573:Agrochemicals / Q000008:administration & dosage / Q000633:toxicity*; D000826:Animal Testing Alternatives; D000818:Animals; D002478:Cells, Cultured; D005123:Eye / Q000187:drug effects*; D007509:Irritants / Q000008:administration & dosage / Q000633:toxicity*; D051379:Mice; D008807:Mice, Inbred BALB C; D009499:Neutral Red; D018675:Toxicity Tests
D016573:Agrochemicals; D007509:Irritants; D009499:Neutral Red
Agrochemical formulations; EpiOcular assay; Eye irritation; In vitro; Neutral red release assay; Ocular irritation