Calculations in Toxicology

Question 1

parts oer million (ppm) on weight/weight basis

Answer 1

most common method of expressing concentrations

Question 2

T/F 1 ppm = 1mg (chemical)/kg (material)

Answer 2

True

1 ppm = 1mg/1,000,00mg

1 ppm = 1 mg/kg

1 ppm = 1 µg/g

Question 3

1 ppb (part per billion)

Answer 3

1 µg/kg

Question 4

1 ppt (part per trillion)

Answer 4

1 ppt = 1 ng/kg

Question 5

how do you convert ppm to percentage

Answer 5

move decimal point 4 places to the left

1 ppm = 0.0001%

Question 6

how to make a diluted solution from a concentrated stock solution

Answer 6

ml needed = (% required dilution / % the stock) x volume required in ml

Question 7

conversion from g/ton in feed to ppm

Answer 7

100g/ton = 110 ppm

• 1g/ton = 1000mg/2000lbs*
• = 1000 mg divided by 2000/2.205*
• = 1000mg/907*
• = 1.1 mg/kg and 1 pm = 1mg/kg*
• then 100 g/ton = 110 ppm*

Question 8

conversion from the level of drug in feed as ppm to toxicity (mg/kg)

Answer 8

toxicity (mg/kg) = ((ppm in feed) x (kg feed eaten daily))/body weight in kg

Question 9

T/F every animal ingests green forage that has been sprayed by a chemical at the rate of 1 lb/acre, will be approximately exposed to 7mg/kg body weight

Answer 9

True

Question 10

conversion from toxicity (mg/kg) to level in feed as ppm

Answer 10

level in feed (ppm) = toxicity (mg/kg) / % of feed consumed daily