Table $1$: Basic events of FTA.

Table $2.$ intermedlate evernts of FTA QUESTION $5$

a$)$ For acetaldehyde, the following was found in the literature:

TLV$-$STEL $=270m\frac{g}{m^3},$

$TLV-C=300m\frac{g}{m^3},$

Explain what these values mean.

b$)$ What is the effect of crystalline silica dust on human body?

c$)$ What is the effect of benzene or vinyl chloride monomer on humans?

d$)$ How would you characterise $($from the toxicological point of view$)$ the following

group of chemicals $($as a whole$)$: acetone, toluene, ether, chloroform?

e$)$ What is the toxic effect of hydrogen cyanide? f$)$ For Ethylene Dichloride, the following was found in the literature:

Oral $L{D}_{50}=770m\frac{g}{k}g,$

Dermal LD $so=3890m\frac{g}{k}g.$

Explain what these values mean.

g$)$ Compare the effects $($from the toxicological point of view$)$ of $N{O}_2$ and $C{O}_2.$

h$)$ Discuss the effect of $C{r}^{3+}$ and $C{r}^{6+}$ on the human body.OUESTION $3$

The top event for the FTA $($Fault Tree Analysis$)$ shown below is a Shell$-$tube heat exchanger

failure. Use Table $1$ and Table $2$ to determine the top event probability if $)$ is equal to $0\mathrm{.}001.$

Further information is provided on page $4.$