Slide � 1 Determining the Aquatic Toxicity of Deicing Materials • Laboratory � based � study � to � evaluate � the � aquatic � toxicity � of � liquid � deicing � chemicals • Acute � and � ”chronic„ � tests • Test � species – Ceriodaphnia � dubia • Water � flea, � zooplankton – Pimephales promelas • Fish, � fathead � minnow – Selenastrum capricornutum • Algae resourceful. naturally.
Slide � 2 The Laboratory resourceful. naturally.
Slide � 3 Study Design • Acute � and � chronic � toxic � effects • Acute – 48 � to � 96 � hour � test – Measure � survival • Chronic – 7 � day � test � (C. � dubia, � fathead) – 4 � day � test � (algae) – Measure � growth, � reproduction, � and � survival • Measureable � outcome � endpoints resourceful. naturally.
Slide � 4 Study Design endpoints • LC50 – Concentration � at � which � there � is � a � 50% � reduction � in � survival... • IC25 – Concentration � at � which � there � is � a � 25% � reduction � in � young � production, � growth... • IC50 – Concentration � at � which � there � is � a � 50% � reduction � in � young � production, � growth... • NOEC – Highest � concentration � at � which � there � is � no � toxicity... ...compared � to � the � controls resourceful. naturally.
Slide � 5 Study Design • Dose � response – Add � a � range � of � volumes � of � deicing � chemical � to � water – Get � a � range � of � responses � from � the � test � organisms – Result � is � a � curve � showing � how � the � organism � responds resourceful. naturally.
Slide � 6 Products Evaluated 1. Watershed � Cl inhibitor � with � sodium � chloride � salt � brine 2. Beet � 55 � inhibitor � with � sodium � chloride � salt � brine 3. FreezGard CI � Plus � inhibitor � magnesium � chloride 4. Meltdown � Apex � inhibitor � magnesium � chloride 5. Road � Guard � Plus � inhibitor � calcium � chloride 6. Boost � inhibitor � calcium � chloride 7. CF � 7 � inhibitor � potassium � acetate 8. Apogee � glycerol resourceful. naturally. 6
Slide � 7 Toxicity Test Dose-Response Example: Watershed CI control 0.50 chronic Fathead � Minnows : � 0.45 FH � Minnow � Weight � (mg) � Day � 7 � of � Test Growth 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 10 20 30 40 50 60 70 80 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally. 7
Slide � 8 Toxicity Test Dose-Response Example: Watershed CI chronic control 20 Ceriodaphnia � dubia: � C. � dubia � Mean � Young � Production � Day � 7 � of �� Test 18 Reproduction 16 14 12 10 8 6 4 2 0 0 2 4 6 8 10 12 14 16 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally. 8
Slide � 9 Toxicity Test Dose-Response Example: Watershed CI chronic Selenastrum 5.0 Mean � Cell � Production � in � Millions � Day � 4 � of �� Test capricornutum: � 4.5 Growth 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 5 10 15 20 25 30 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally.
Slide � 10 Toxicity Test Dose-Response Example: Watershed CI Acute � and � Chronic Fathead � Minnows : � 100 Survival 90 FH � Minnow � Percent � Survival 80 70 96 � Hour: � Acute 60 50 7 � Day: � Chronic 40 30 20 10 0 0 10 20 30 40 50 60 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally.
Slide � 11 Toxicity Test Dose-Response Example: Watershed CI Acute � and � Chronic Ceriodaphnia � dubia: � Survival 100 90 80 C. � dubia � Percent � Survival 48 � Hour: � Acute 70 7 � Day: � Chronic 60 50 40 30 20 10 0 0 5 10 15 20 25 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally.
Slide � 12 Endpoints example RoadGard Plus chronic 0.40 FH � Minnow � Weight � (mg) � Day � 7 � of � Test 0.35 Fathead � Minnows : � Growth 25% � reduction 0.30 IC25=2.46 0.25 0.20 0.15 0.10 0.05 0.00 0 1 2 3 4 5 6 7 8 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally.
Slide � 13 Endpoints example RoadGard Plus chronic 0.40 FH � Minnow � Weight � (mg) � Day � 7 � of � Test 0.35 Fathead � Minnows : � Growth 50% � reduction 0.30 0.25 0.20 IC50=3.30 0.15 0.10 0.05 0.00 0 1 2 3 4 5 6 7 8 Product � Concentration � (grams � product � per � liter � of � MH � laboratory � water) resourceful. naturally.
Slide � 14 Endpoint Tables mass based Ceriodaphnia � dubia Toxicological � Endpoint � as � Product � (grams � product/liter � of � diluent) Acute � Acute � Chronic � Chronic � NOEC � Chronic � IC25 � Chronic � IC50 � NOEC � LC50 � NOEC � Chronic � LC50 � (young � (young � (young � Product (survival) (survival) (survival) (survival) production) production) production) Watershed � Cl: � Inhibitor � + � Salt � (NaCl) 12.0 17.0 3.00 4.81 1.00 0.990 3.43 Mass � of � Product/Volume � of � Diluent � = � Mass � of � liquid � product � diluted � in � runoff � and � the � receiving � water � body resourceful. naturally.
Slide � 15 Endpoint Tables volume based Ceriodaphnia � dubia Toxicological � Endpoint � as � Product � (milliliters � of � product/liter � of � diluent) (1) Acute � Chronic � Chronic � NOEC � Chronic � IC25 � Chronic � IC50 � NOEC � Acute � LC50 � NOEC � Chronic � LC50 � (young � (young � (young � Product (survival) (survival) (survival) (survival) production) production) production) Watershed � Cl � : � Inhibitor � + � Salt � (NaCl) 9.4 13.3 2.3 3.8 0.8 0.8 2.7 Volume � of � Product/Volume � of � Diluent � = � volume � of � liquid � product � diluted � in � runoff � and � the � receiving � water � body For � the � practitioner! resourceful. naturally.
Slide � 16 Endpoint Tables salt content based Ceriodaphnia � dubia Toxicological � Endpoint � as � Primary � Salt � (milligrams � salt/liter � of � diluent) 1 Stock � Chemical � Concentration � Chronic � Used � for � (grams � salt � / � Acute � Acute � Chronic � Chronic � NOEC � Chronic � IC25 � Chronic � IC50 � Endpoint � liter � of � NOEC � LC50 � NOEC � LC50 � (young � (young � (young � Product Calculation product) 2 (survival) (survival) (survival) (survival) production) production) production) Watershed � Cl : � Inhibitor � Na � + � Cl 288 2705 3826 676 1084 225 223 773 + � Salt � (NaCl) Beet � 55: � Inhibitor � + � Salt � Na � + � Cl 224 1760 2782 17.6 102 1.76 12.4 64.8 (NaCl) Mass � of � salt � per � volume � of � product/volume � of � diluent � = � mass � of � salt � diluted � in � runoff � and � the � receiving � water � body To � normalize � products � based � upon � salt � mass � per � unit � volume � and � to � promote � comparison Which � inhibitor � is � more � chronically � toxic? resourceful. naturally.
Slide � 17 Ranking Ranking � by � Total � Product � Mass Ranking � by � Salt � Mass Relative � Relative � Toxicological � Toxicological � Product Rank Product Rank Watershed � Cl: � Inhibitor � + � Salt � Watershed � Cl: � Inhibitor � + � Salt � (NaCl) 1 (NaCl) 1 Boost � (CaCl2) 2 Boost � (CaCl2) 2 Road � Guard � Plus � (CaCl2) 3 Road � Guard � Plus � (CaCl2) 3 less � toxic FreezGard CI � Plus � (MgCl2) 4 Beet � 55: � Inhibitor � + � Salt � (NaCl) 4 Meltdown � Apex � (MgCl2) 5 FreezGard � CI � Plus � (MgCl2) 5 Apogee � (Glycerol) 6 Beet � 55: � Inhibitor � + � Salt � (NaCl) 6 Meltdown � Apex � (MgCl2) 7 CF � 7 �� (K � Acetate) 7 CF � 7 �� (K � Acetate) 8 resourceful. naturally.
Slide � 18 Ranking by Salt Type For � this � current � study � (from � most � to � least � toxic): K � Acetate � > � MgCl 2 > � CaCl 2 > � NaCl Salt � only � toxicity � from � the � literature: K � Acetate � > � MgCl 2 > � CaCl 2 = � NaCl resourceful. naturally.
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