Routes matter. In fact, the route you take can become important. Take the Routes of Entry for example. The Routes of Entry are the four main ways that hazardous materials can gain entry into your body and cause harm. Knowing the routes of entry and understanding control measures you can take for preventing exposure to those hazardous materials becomes important.
The Canadian Centre for Occupational Health and Safety has a well prepared fact sheet on the routes of entry, linked here. The four routes of entry are:
- Inhalation – You can be harmed by breathing in the hazard.
- Skin or eye contact, sometimes known as absorption – The harm from the chemical is most often to your skin or eyes. However, many types of chemicals may enter your body and become systemic, affecting internal organs as well. An example of this is transdermal medication which allows certain types of drugs to be absorbed at a prescribed rate.
- Ingestion – You can be harmed by swallowing the chemical.
- Injection – A sharp object, such as a needle, injects the chemical into your system, or an opening in your skin provides an open pathway for materials to get inside.
Not all chemicals are alike. They can cause harm through different routes. So it becomes important to know which route we need to protect to prevent a harmful exposure. How do we do that? There are at least two ways. We can look at the warning label on the material and we can read the Safety Data Sheet (SDS).
Let’s take a look at a chemical that many of us have in our barbeque, propane. You may have seen warning signs on the cylinder that it is flammable, which is what we want when we are trying to cook food with it. Have you looked at the SDS for propane? If not, here’s the link.
First, look at Section 2, Hazard Identification and find the Hazard Statements. We already know that it is flammable. But were you expecting these statements? “May cause frostbite.” “May displace oxygen and cause suffocation.”
Now scroll down to Section 4, First Aid Measures and find the Potential Acute Health Effects. Surprisingly, it states that inhalation is not an acute hazard. But eye contact and ingestion are acute hazards. Ingestion? Yes, if the liquified gas gets onto our hands, and from there it gets into our mouth, the SDS tells us that we could get internal burns similar to frostbite. How do we protect ourselves from that? We wear gloves and wash our hands before touching anything.
This information is confirmed in Section 8, Exposure Controls/Personal Protection. The first thing the SDS tells you is to use engineering controls, which is to have adequate ventilation. Further down, you will see it advises you to wear safety glasses and gloves.
Not all hazards have the same route of entry. And just because it can be used in your home does not make it completely safe. Check out this
It’s a strong oxidizer, it’s an ingestion hazard (harmful if swallowed), it can cause skin burns and eye damage, and it’s an inhalation hazard (harmful if inhaled). To top it off, if it gets into a waterway, it is harmful to fish and algae. That covers at least three out of four of our routes of entry.