Material Safety Data Sheet User's Guide

6. Hazardous ingredients

This section of the MSDS includes the following:

Chemical name and ingredient concentration,

i) which are controlled products if they are present at a concentration equal to or greater than 0.1% in the mixture (applies to ingredients that are teratogenic, embryotoxic, carcinogenic, toxic to reproduction, mutagenic and respiratory tract sensitizers). In other cases, ingredients that are themselves controlled products and whose concentration is above 1% are disclosed;
ii) which are on the ingredient disclosure list, if their concentration is equal to or greater than the concentration on this list (even if the ingredient is not a controlled product as defined in WHMIS);
iii) which the supplier believes, based on reasonable grounds, to be harmful to the health of the workers;
iv) whose toxicological properties are unknown.

The concentration is defined as being the amount of a component in the total amount of the mixture. It can be expressed as a percentage (%) and interpreted as being a ratio:

• Weight of component/weight of mixture (W/W), or
• Weight of component/volume of mixture (W/V), or
• Volume of component/volume of mixture (V/V).

On the MSDS, the actual concentration of the ingredient can be replaced by one of the following permitted ranges of concentrations, namely:

• from 0,1 to 1 %
• from 0,5 to 1,5 %
• from 1 to 5 %
• from 3 to 7 %
• from 5 to 10 %
• from 7 to 13 %
• from 10 to 30 %
• from 15 to 40 %
• from 30 to 60 %
• from 40 to 70 %
• from 60 to 100 %

CAS registry number

The CAS number is assigned by the Chemical Abstracts Service, a division of the American Chemical Society, to precisely identify a chemical substance.

Lethal dose 50 (LD₅₀)

This is the amount of a substance that causes the death of 50% of the laboratory animals exposed to it orally (ingestion) or cutaneously. There are other routes of entry (for example by injection), but WHMIS does not take them into account.

Lethal concentration 50 (LC₅₀)

This is the concentration of a substance in the air that causes the death of 50% of the laboratory animals exposed to it by inhalation, generally for 4 hours.

Pure product:
Hazardous ingredient	CAS	Concentration	LD50	LC50
Ammonia	7664-41-7	60-100 %		Rat : 2,000 ppm/4h
Product composed of several ingredients:
Hazardous ingredient	CAS	Concentration	LD50	LC50
Methyl yellow	60-17-7	0.1-1 %	Rat, oral: 200 mg/kg Mouse, oral : 300 mg/kg
Ethylene glycol	107-21-1	60-100 %	Rat, oral : 4.7 g/kg Mouse, oral: 7.5 g/kg Rabbit, skin: 9.5 g/kg