Restricted Methods

Restricted methods usually apply to hazardous materials or perishable items.

For hazardous materials, usually any kind of air shipping method is not allowed.

For perishable materials, usually ground or slower shipping methods are not allowed.

Example:

You have a product catalog with non-hazardous product and hazardous products.
Non-Hazardous products ship UPS Ground, UPS 2-Day, and UPS Overnight.
Hazardous products ship only via UPS Ground, and cannot be shipping to Hawaii/Alaska.

Steps:

Create a product group for the restricted products. You should have at least 2 product groups. The default product group for non-hazardous products, and a another product group for for hazardous products.
Go to Shopify Admin > Settings > Shipping and make sure you have separate zones for 48 States, and a zone for Hawaii Alaska. ( If you make an edit to your shipping zones, in the app go to Settings > General > Sync Shipping Zones, after that you should see the zones you have in the Shopify settings appear under each product group ).
In the default product group for the non-hazardous products, set-up the UPS Ground, UPS 2-Day, UPS Overnight, rates in both zones.
In the hazardous product group, set up only UPS Ground as a rate for the 48 States. Set-up no rates in the Hawaii/Alaska zone.
In the Hawaii/Alaska zone you should see a gray badge Rate Failure Enabled. If you do not see this badge, go to Settings > General, scroll to the bottom of the screen, and click Enable Rate Failure.

The outcome for this will be.

When an order contains all non-hazardous products, UPS Ground, UPS 2-Day, UPS Overnight will appear as options shipping to all zones.
When an order contain all hazardous products, only UPS Ground will appear when shipping to 48 States, and no shipping methods will appear if shipping to Hawaii/Alaska.
When an order contains both hazardous products and non-hazardous products, the Standard Shipping blended method ( you can edit the blended rate title ) will be the only method shipping to 48 States, and no shipping methods will appear if shipping to Hawaii/Alaska.

Example:

You have perishable products that need to arrive to your customer within 2 shipping days.
You have regular products that can be shipped UPS Ground, UPS 2-Day, and UPS Overnight.
You have a nearby shipping zone, that can have the perishable products shipped UPS Ground because it has only a 2-day transit time.
You have far away shipping zone, that can not have the perishable products shipping UPS Ground because it has more than a 2-day transit time, these zones need to be serviced always with a 2-Day shipping rate.

Steps:

Create a product group for the perishable items.
Go to Shopify Admin > Settings > Shipping and make sure you have separate zones for nearby zone, and and far away zone. ( If you make an edit to your shipping zones, in the app go to Settings > General > Sync Shipping Zones, after that you should see the zones you have in the Shopify settings appear under each product group ).
For the perishable product group, assign only UPS Ground to the near-by zone. And assign only Express options to the far away zone.
For your regular items assign UPS Ground only for near zone, and assign UPS Ground and Express items to far away zone.
In the far away zone for your regular items, you can choose either the express option or the ground option as the preferred method for the blended rate.

Outcome:

When someone orders a perishable product to a nearby zone, they will see UPS Ground.
When someone orders a perishable product to far away zone, they will see only Express methods.
When someone order a non-perishable product to a nearby zone, they will see UPS Ground.
When someone orders a non-perishable product to a far away zone, they will see UPS Ground and Express options.
When someone orders both non-perishable and perishable product to a nearby zone, they will see the Standard Shipping blended rate ( you can edit this blended rate title ). The rate will be the cost to to ship non-perishable via UPS Ground plus the cost to ship perishable via UPS Ground. ( You can use blending rules to reduce this price, or make one of these items ship free, when shipped together ).
When someone orders both non-perishable and perishable product to a nearby zone, they will see the Standard Shipping blended rate ( you can edit this blended rate title ). The rate will be the cost to to ship non-perishable via UPS 2-Day plus the cost to ship perishable via UPS 2-Day. ( You can use blending rules to reduce this price, or make one of these items ship free, when shipped together ).