What is the best gas mask and coveralls and do they have any for toddler?
That is a really good qeustion. There are two factors. 1. how active do you plan to be? 2. would you like to be able to eat in it.
At the top of the line you more or less have space suits, however they are heavy and not something you will want to run aronud in, your mobility may be constricted etc..
IMO
you have three basic options
a civillian gas mask
a military gas mask
an industrial gas mask
If cost is not a factor on filters etc..
for the military mask I like the M52/GSR which is a british and special forces version of the M50 gas mask. These masks are newer they are not super rare and they are adapted for tactical use. The big benefit of these masks is that military gas masks often have drinking tubes.
You may want to take a look at what is being used by HAZMAT teams, the CDC, etc..
The truth is you don't want a gas mask for the top line stuff you will want a closed circuit rebreather that is pressurized.
However it is often more convienient to just use a gas mask.
It may come down to the shape of your head, different gas masks fit differently, and may have different types of filters available.
For myself I picked a relatively low cost mask with a standard nato 40mm filter attachment potential. I do not expect it to protect me in all incidences, I also have a secondary particle mask for particles that may not be protected, however it is pretty much spent and needs to be replaced.
One peice suits are best for a stationary situation.
For the stuff you mention something like this may be good if you don't plan on tactical operations during the incident.
http://www.ebay.ca/itm/Dupont-Tyche...LH_DefaultDomain_0&hash=item2c7095cfe6&_uhb=1
As far as childrens sizes this is more problematic for suits... there are child sized gas masks for instance the israeli gas mask.
older russian models exist also.. there are specific instances in which you will need to carefully pick your gas mask and this requires a little knowledge on how different materials react to different types of exposures. It is absolutely absolutely important to train your child how to use a gas mask properly and keep them safely stored where a todler does not have access to them, as they are not toys and can seriously injure people if used improperly.
here are some examples of tolders masks.
http://www.ebay.ca/itm/Soviet-russi...LH_DefaultDomain_0&hash=item3f26cca5ce&_uhb=1
http://www.ebay.ca/itm/NEW-Child-Ga...LH_DefaultDomain_0&hash=item2ec100a87e&_uhb=1
http://www.ebay.ca/itm/Israeli-Yout...LH_DefaultDomain_0&hash=item257f167954&_uhb=1
You are best advised to contact companies directly about child sized suits such as Dupont, 3M and other chemical manufacturers. You best bet short of this is to get the smallest size available and tape down or roll over arms and leg portions to double it up by rolling up the parts properly then taping the ends.
There are lots of options...
none the less... look to what your militaries HAZMAT teams use as well as what the nuclear plant safety teams use
I would suggest looking into this in more detail before buying anything however without money constraints
Note this is what the US military is training with
You will note that most of the Terrorist reponse units have one peice type CBRN jump suits either with a gas mask such as the m52 type or a fully enclosed system as seen in the youtube video above.
You will be looking for the term OSHA LEVEL A in your suit but chances are you will probably settle for OSHA LEVEL B or class 2.
example
the video before this one was class 2.
This may be helpful
https://rdl.train.army.mil/catalog/...D-6BEAD5A8D6EF-1274315130406/4-02.7/chap5.htm
watch this
Other considerations are 1. are you within the lethal exposure area or outside it, if you are outside it then