Portable Oxygen Tanks

Your main concern is he DOT medically qualified? Anybody on oxygen has to have a PFT (pulminary function test) and approved by the DOT doctor. Most are not approved. But if the DOT doctor says okay and you have the long form in your possession, then he'll be okay.

If he just got put on oxygen recently, then he needs to go get another physical quick. He shouldn't be driving on an old medical card that's still not expired.

As far as the tank goes, if it's secured in a vertical position, they won't say a word. Spare bottles need to be secured vertically with the cap on the tank. I can't find it now, but I remember reading it can't be over a 35 lb bottle or so. Most little bottles aren't. You just can't have one of them big oxygen welding bottles.

 

If your husband can continue as a driver he needs to be aware of two hazards:

Oxygen reacts explosively with hydrocarbons (i.e. diesel fuel, oil, any other petroleum based product) so be sure that these items or anything that is covered with them do not come into contact with the equipment.

Oxygen is an oxidizer and will vigorously accelerate combustion.

Due to the size of the equipment the hazard risk should be small but care should still be taken.